Research abstracts

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Title:
Research abstracts
Physical Description:
93 v. : ; 27 cm.
Language:
English
Creator:
United States -- National Advisory Committee for Aeronautics
Publisher:
National Advisory Committee for Aeronautics
Place of Publication:
Washington, D.C
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irregular
completely irregular

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Subjects / Keywords:
Aeronautics -- Abstracts -- Periodicals   ( lcsh )
Aeronautics -- Research -- Abstracts -- Periodicals   ( lcsh )
Genre:
serial   ( sobekcm )
federal government publication   ( marcgt )
abstract or summary   ( marcgt )

Notes

Statement of Responsibility:
National Advisory Committee for Aeronautics.
Dates or Sequential Designation:
Abstracts no. 1 (June 15, 1951)-no. 93 (Nov. 30, 1955).

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 001469326
notis - AGY1019
oclc - 01471285
lccn - 86657025
issn - 0499-9274
Classification:
lcc - TL501 .U5895
System ID:
AA00009235:00021

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National Advisory Committee For Aeronautics


Research Abstracts


NO.60


MARCH 30, 1954


CURRENT NACA REPORTS

NACA Rept. 1114

A THERMODYNAMIC STUDY OF THE TURBINE-
PROPELLER ENGINE. Benjamin Pinkel and
frying M. Karp. 1953. ii, 36p. diagrs. (NACA
Rept. 1114. Formerly TN 2653)

Equations and charts are presented for computing
performance parameters of a turbine-propeller en-
gine for any given set of operating conditions and
component elliciencies. In order to illustrate some
of the turbine-propeller system performance charac-
teristics, the total thrust horsepower per unit mass
rate of air flow and the specific fuel consumption are
presented for a wide range of flight engine design
operating conditions and given design component ef-
ficiencies. The performance of a turbine-propeller
engine containing a matched set of components is
presented for a range of engine operating conditions.
Tne influence of the characteristics of the individual
components of off-design-point performance is
shown. The flexibility of operation of two turbine-
propeller engines is discussed; one engine has a
divided turbine system in which the first turbine
drives only the compressor and the second turbine
independently drives the propeller, and the other
engine has a connected turbine system which drives
both the compressor and the propeller.


NACA Rept. 1115

DESIGN OF TWO-DIMENSIONAL CHANNELS WITH
PRESCRIBED VELOCITY DISTRIBUTIONS ALONG
THE CHANNEL WALLS. John D. Stanitz. 1953.
ii, 40p. diagrs., 8 tabs. INACA Rept. 1115. For-
merly TN 2593. TN 2595)

A general method of design is developed for two-
dimensional unbranched channels with prescribed
velocities as a function of arc length along the chan-
nel walls. The method is developed lor both com-
pressible and incompressible, irrotational, non-
viscous flow and applies to the design of elbows,
diffusers, nozzles, and so forth. Two types of
compressible flow are considered: the general type,
with the ratio of specific heats equal to 1.4, for ex-
ample, and the linearized type, in which the ratio of
specific heats is -1.0. Two methods of solution are
used. In part I, solutions are obtained by relaxation
methods and in part II, solutions are obtained by a
Green's function.


NACA Rept. 1116

APPLICATION OF A CHANNEL DESIGN METHOD
TO HIGH-SOLIDITY CASCADES AND TESTS OF AN
IMPULSE CASCADE WITH 900 OF TURNING.
John D. Stanitz and Leonard J. Sheldrake. 1953.
ii, 20p. diagrs., photos., 2 tabs. (NACA
Rept. 1116. Formerly TN 2652)

A technique is developed for the application of a
channel design method to the design of high-solidity
cascades with prescribed velocity distributions as a
function of arc length along the blade-element profile.
The technique applies to both incompressible and
subsonic linearized compressible (ratio of specific
heats equal to -1. 0), nonviscous, irrotational, fluid
motion. An impulse cascade with 900 turning was
designed for incompressible flow and was tested at
the design angle of attack over a range of downstream
Mach number from 0.2 to choke flow. To achieve
good efficiency, the cascade was designed for pre-
scribed velocities with maximun. allowable blade
loading according to inmitations imposed by con -
siderations of bound yeijseparation.

.e.
NACA Rept. 1124 \ \ "-3
J71-1-,14 '-'
DISPLACEMENT EFFEtI T CrF fB -
DIMENSIONAL BOUND Y LA HM I K.
Moore. 1953. ii. 5p. dik.5rlr NACA Rept. 1124.
Formerly TN 2722)

A method is described for determining the "displace-
ment surface" of a known three-dimensional com-
pressible boundary-layer flow in terms of the mass-
flow defects associated with the profiles of the two
velocity components parallel to the surface. The
result is a generalization of the plane flow concept
of displacement thickness introduced in order to
describe how a thin boundary layer distorts the outer
nonviscous flow. Numerical values are found for
the known three-dimensional boundary-layer flow
about a cone at a small angle of attack to a super-
sonic stream.



NACA Rept. 1127

ONE-DIMENSIONAL ANALYSIS OF CHOKED-FLOW
TURBINES. Robert E. English and Richard H.
Cavicchi. 1953. ii, 18p. diagrs. (NACA
Rept. 1127. Formerly TN 2810)


'AVAILABLE ON LOAN ONLY
ADDRESS REQUESTS FOR DOCUMENTS TO NACA, 1724 F ST., NW., WASHINGTON s25, D. C, CITING CODE NUMBER ABOVE EACH TITLE,
THE REPORT TITLE AND AUTHOR.
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2


It is indicated that the area ratios and equivalent
blade speed are the controlling factors in the design
and operation of high work output turbines. For the
usual class of turbine, increasing the equivalent
blade speed of a given stage makes the internal flow
conditions less critical. Flow conditions within
choked-flow turbines are not usually sensitive to
manufacturing errors in area ratio even near the
stator choking limit. Six criteria are stated that
will aid in establishing from test data of multistage
turbines which blade rows are choked and which are
not. The variation in internal flow conditions with
operating conditions for a turbine equipped with an
adjustable stator is determined for one application of
stator adjustment.


NACA Rept. 1130

SOME EFFECTS OF FREQUENCY ON THE CONTRI-
BUTION OF A VERTICAL TAIL TO THE FREE
AERODYNAMIC DAMPING OF A MODEL OSCIL-
LATING IN YAW. John D. Bird, Lewis R. Fisher
and Sadie M. Hubbard. 1953. ii, 17p. diagrs.,
photo. (NACA Rept. 1130. Formerly TN 2657)

The directional damping and stability of a fuselage -
vertical-tail model oscillating freely in yaw were
measured at a Mach number of 0.14 and compared
with the damping and stability obtained by considera-
tion of the effects of unsteady lift. The effects of
vertical-tail aspect ratio and compressibility as
predicted by the theoretical treatments are dis-
cussed in relation to the experimental stability char-
acteristics obtained by the free-oscillation and by
the curved-flow procedures.


NACA TN 3073

EXPERIMENTAL STRESS ANALYSIS OF STIFFENED
CYLINDERS WITH CUTOUTS. PURE BENDING.
Floyd R. Schlechte and Richard Rosecrans.
March 1954. 41p. diagrs., photo., 7 tabs. (NACA
TN 3073)

Bending tests were made on a cylindrical semi-
monocoque shell of circular cross section. The
cylinder was tested without a cutout and then with a
rectangular cutout which was successively enlarged
through six sizes varying from 300 to 1300 in cir-
cumference and from 1 to 2 bays in length. Strain
measurements were made with resistance-type wire
strain gages near the cutout on the stringers, the
skin, and the rings for each size of cutout, and the
stresses obtained are presented in tables.


NACA TN 3074

A PRELIMINARY INVESTIGATION OF THE
EFFECTS OF GUSTY AIR ON HELICOPTER-BLADE
BENDING MOMENTS. Joseph W. Jewel, Jr. and
Paul J. Carpenter. March 1954. 28p. diagrs.,
photos. (NACA TN 3074)

A preliminary investigation has been made at the
Langley helicopter test tower to determine the bend-


NACA
RESEARCH ABSTRACTS NO.60


ing moments excited on typical helicopter rotor
blades in quiet and gusty air. The results obtained
from this investigation indicate that the effect a of-.
gusts on rotor-blade bending moments appear to be
secondary compared with the vibratory moments
attributed to the unsymmetrical rotor downwash for
the 26-mph condition tested and analyzed. It was
also found that the addition of weights at the blade
tips reduced the magnitude of the blade vibratory
bending moments.


NACA TN 3075

MEASUREMENTS OF PRESSURE AND TEMPERA-
TURE FOR APPRAISAL OF THE TEMPERATURE
METHOD OF AIRSPEED CALIBRATION IN THE
LOWER STRATOSPHERE. Lindsay J. Lina.
March 1954. 12p. diagrs., photo. (NACA
TN 3075)

An investigation was made to determine whether the
temperature and pressure conditions in the lower
stratosphere would meet the requirements of the
temperature method for accurate calibration of air-
speed installations. Measurements of temperature
and pressure were made in flights of a swept-wing
fighter airplane on four clear days in March and
April 1953 over land near Langley Field, Virginia.
The results indicated that, although the temperature
lapse rate was favorable to the method, large and
erratic variations of temperature with time and dis-
tance precluded accurate calibration. Unfavorable
atmospheric conditions had also been found previous-
ly in an investigation of the upper troposphere
(NACA TN 2807).


NACA TN 3096

THEORETICAL PREDICTION OF PRESSURE DIS-
TRIBUTIONS ON NONLIFTING AIRFOILS AT HIGH
SUBSONIC SPEEDS. John R. Spreiter and Alberta
Alksne. March 1954. (ii), 84p. diagrs. (NACA
TN 3096)

Theoretical pressure distributions on nonlifting
circular-arc airfoils in flows with high subsonic
free-stream velocity are found by determining
approximate solutions of an integral equation for
transonic flow proposed by Oswalitsch. Solutions
are obtained using an iteration process which differs
from the classical methods in that the quadratic
nature of the integral equation is recognized. Ex-
cept for phenomena which are predominantly in-
fluenced by viscous effects, the results are in good
accord with experimental data.


NACA TN 3097

TURBULENT BOUNDARY-LAYER AND SKIN-
FRICTION MEASUREMENTS IN AXIAL FLOW
ALONG CYLINDERS AT MACH NUMBERS BE-
TWEEN 0.5 AND 3.6. Dean R. Chapman and Robert
H. Kester. March 1954. 53p. diagrs., photos.,
5 tabs. (NACA TN 3097)








NACA
RESEARCH ABSTRACTS NO. 60


Direct-force measurements have been made of the
average skin-friction coefficient for completely tur-
bulent flow along the cylindrical portion of heat-
insulated cone-cylinder bodies of revolution having
overall fineness ratios of 10, 15, and 25. Numerous
boundary-layer surveys were made. Reynolds num-
bers between 4 million and 32 million were investi-
gated. At a Mach number of 2.0, data were obtained
for different pressure distributions by distorting the
flexinle-plale walls of the wind tunnel. The results
show no significant effect of small pressure gradi-
ents and only a small effect of cylinder fineness ratio
on the average skin-friction coefficient. For each
fineness ratio the effect of Mach number is large
and essentially the same for all Reynolds numbers
investigated. Determinations of friction by the
momentum method differed considerably from the
more reliable direct-force measurements.


NACA TN 3099

IMPINGEMENT OF WATER DROPLETS ON AN
ELLIPSOID WITH FINENESS RATIO 5 IN AXISYM-
METRIC FLOW. Robert G. Dorsch, Rinaldo J.
Brun and John L. Gregg. March 1954. 50p. diagrs.,
tab. (NACA TN 3099)

The presence of radomes and instruments that are
sensitive to water films or ice formations in the nose
section of all-weather aircraft and missiles necessi-
tates a knowledge of the droplet impingement char-
acteristics of bodies of revolution. Because it is
possible to approximate many of these bodies with an
ellipsoid of revolution, droplet trajectories about an
ellipsoid of revolution with a fineness ratio of 5 were
computed for incompressible axisymmetric air flow.
From the computed droplet trajectories, the following
impingement characteristics of the ellipsoid surface
were obtained and are presented in terms of dimen-
sionless parameters: (1) total rate of water impinge-
ment, (2) extent of droplet impingement hone,
(3) distribution of impinging water, and (4) local
rate of water impingement.


NACA TN 3100

STATISTICAL STUDY OF TRANSITION-POINT
FLUCTUATIONS IN SUPERSONIC FLOW. J. C.
Evvard, M. Tucker and W. C. Burgess, Jr. Appen-
dix B. MATHEMATICAL PROCEDURES. Hugo
Heermann. March 1954. 32p. diagrs., photos., tab.
(NACA TN 3100)

The random movement of the transition point on a 100
cone at a free-stream Mach number of 3.12 was in-
vestigated by means of a large number of high-speed
schlieren photographs. The distribution functions
which statistically define the transition-point loca-
tion were determined for a range of test-section
Reynolds number and two levels of free-stream tur-
bulence intensity. The intensity was varied by
changing tunnel settling-chamber configurations.
Temnperature-recovery-factor distributions were also
obtained. The axial extent of the distribution func-
tion determined from the schlieren data increased
with turbulence level. The axial spread of the transi-
tion region denoted by the recovery-factor measure-
ments roughly corresponded to that of the appropriate
distribution function. These data suggest that a


3


relatively sharp transition from laminar to turbulent
flow takes place and that this flow pattern moves
randomly along the aerodynamic surface. With the
use of the statistical distribution functions obtained
from the data and surface temperatures (as time-
averaged by the surface thermocouples), the instan-
taneous surface-temperature distributions were cal-
culated for two Reynolds numbers.


NACA TN 3102

AN ANALYTICAL AND EXPERIMENTAL STUDY OF
THE TRANSIENT RESPONSE OF A PRESSURE-
REGULATING RELIEF VALVE IN A HYDRAULIC
CIRCUIT. Harold Gold and Edward W. Otto.
March 1954. 54p. diagrs., photo., 3 tabs.
(NACA TN 3102)

The transient response of the pressure-regulating
relief valve in a hydraulic circuit is analyzed by
means of an electrical analogy of the hydraulic cir-
cuit. Measurements of the transient response of a
hydraulic relief valve are presented and are com-
pared with responses calculated from the differential
equation of the equivalent electric network. The
comparison of experimental and analytical responses
shows that the response of the relief valve can be
adequately predicted by means of the equivalent net-
work. The analysis of a typical relief valve by
means of the equivalent network indicates that
viscous damping is negligible and that the principle
damping is derived from the flow resistance of the
various elements of the hydraulic circuit. An ex-
pression is analytically developed that yields
directly the area-lift relation for the relief valve for
stable valve operation over the wide flow-rate
ranges.


NACA TN 3103

COOLING REQUIREMENTS FOR STABILITY OF
LAMINAR BOUNDARY LAYER WITH SMALL PRES-
SURE GRADIENT AT SUPERSONIC SPEEDS. George
M. Low. March 1954. 16p. diagrs., tab. (NACA
TN 3103)

The amount of cooling required to stabilize the two-
dimensional supersonic laminar boundary layer for
all Reynolds numbers is calculated for flows with
pressure gradients of a magnitude usually encoun-
tered over slender aerodynamic shapes. Only two-
dimensional disturbances are treated in the stability
calculations. It is determined that small pressure
gradients have an appreciable effect on stability. The
cooling due to radiation alone may suffice, at moder-
ate supersonic Mach numbers, to completely stabilize
the boundary layer over wings with favorable pres-
sure gradients. For flows with adverse pressure
gradients, the cooling required for complete stability
is considerably greater than that for flat-plate flows.


NACA TN 3104

EXPERIMENTAL INVESTIGATION OF SUBLIMA-
TION OF ICE AT SUBSONIC AND SUPERSONIC
SPEEDS AND ITS RELATION TO HEAT TRANSFER.
Willard D. Coles and Robert S. Ruggeri. March
1954. 29p. diagrs., photo. (NACA TN 3104)








4

An experimental investigation was conducted in the
3.84- by 10-inch tunnel to determine the mass trans-
fer by sublimation, heat transfer, and skin friction
for an iced surface at subsonic and supersonic
speeds. The results show that the Stanton numbers
of sublimation and heat transfer were increased 40
to 50 percent for an iced surface of moderate rough-
ness as compared with those obtained for a bare
plate. For ice surfaces of equivalent roughness, the
ratio of sublimation to heat-transfer Stanton numbers
was found to be 0.90. Sublimation Stanton numbers
obtained at a Mach number of 1.3 showed no appreci-
able deviation from those obtained at subsonic
speeds. Sublimation as a means of removing ice
formations of appreciable thickness is so slow as to
be of little value in the de-icing of aircraft at high
altitudes.


NACA TN 3105

AERODYNAMICS OF SLENDER WINGS AND WING-
BODY COMBINATIONS HAVING SWEPT TRAILING
EDGES. Harold Mirels. March 1954. ii, 96p.
diagrs. (NACA TN 3105)

A general method, based on two-dimensional cross-
flow concepts, is presented for obtaining the lift and
moments on highly swept wings. Emphasis is placed
on obtaining solutions for wings having swept trailing
edges. The method is applicable for all problems
where the velocity boundary conditions can be made
homogeneous by differentiation in the streamwise or
spanwise directions. Lift, roll, and pitch solutions,
for highly swept wings, are presented. Both direct
problems and inverse problems are considered.
Applications of the method for the solution of wing-
body problems and unsteady two-dimensional incom-
pressible flow problems are also indicated.


NACA TN 3107

EFFECT OF HEAT TREATMENT UPON THE
MICROSTRUCTURE AND HARDNESS OF A
WROUGHT COBALT-BASE ALLOY SATELLITE 21
(AMS 5385). F. J. Clauss and J. W. Weeton.
March 1954. 26p. diagrs., photos. (NACA
TN 3107)

An investigation has been made to study the response
of wrought Stellite 21 to heat treatment. A period of
72 hours at 22500 F was sufficient for effective solu-
tion treatment of this alloy. Pearlitic structures
formed at grain boundaries of solution-treated speci-
mens during isothermal transformation at 19500,
17500, and 15000 F. A Widmanstaetten structure
also formed during transformation at 17500 and
15000 F. Little visible precipitate formed by trans-
formation at 12000 F for times up to 72 hours.
Water quenching from 22500 F followed by aging at
temperatures from 12000 to 19500 F resulted in
precipitation principally along slip lines and twin
boundaries. Spheroidization and agglomeration of
precipitates occurred at temperatures as low as
15000 F. Isothermal or aging treatments above
12000 F increased the hardness of the solution-
treated specimens. A maximum hardness of
Rockwell C-42 was developed by aging 72 hours in
the temperature range from 14000 to 15000 F, as


NACA
RESEARCH ABSTRACTS NO.60

compared to Rockwell C-20 to C-22 for theolution-
treated condition. Overaging or softening occulfedi
within 72 hours at temperatures of 17500 F and *
above for aging, and 19500 F for isothermal trans-
formation.


NACA TN 3108

RELATION OF MICROSTRUCTURE TO HIGH-
TEMPERATURE PROPERTIES OF A WROUGHT
COBALT-BASE ALLOY SATELLITE 21 (AMS 5385).
F. J. Clauss and J. W. Weeton. March 1954. 49p.
diagrs., photos., tab. (NACA TN 3108)

An investigation was conducted to determine the ef-
fects of microstructure on stress-rupture life of
heat-treated wrought Stellite 21. Wrought Slellile 21,
which may be considered a typical cobalt-base
precipitation-hardening alloy, was found to respond
readily to solution treatment and to isothermal and
aging heat treatments to form pearlitic and
Widmanstitten structures as well as scattered
precipitates. The results obtained in this investiga-
tion, although determined specifically for the alloy
wrought Stellite 21, lead to conclusions that are
believed to have general significance in the heat
treatment of other high-temperature alloys. The
optimum high-temperature properties are associated
with a dispersion of fine precipitate scattered
throughout the grains of the microstructure. Such
scattered precipitation was produced by solution
treatment followed by a low-temperature aging treat-
ment to develop nucleation sites and higher-
temperature age to develop visible precipitation in
the scattered nucleation sites.


NACA TN 3109

AN INVESTIGATION OF LAMELLAR STRUCTURES
AND MINOR PHASES IN ELEVEN COBALT-BASE
ALLOYS BEFORE AND AFTER HEAT TREATMENT.
J. W. Weeton and R. A. Signorelli. March 1954.
50p. diagrs., photos., 12 tabs. (NACA TN 3109)

An investigation of the occurrence and nature of
lamellar structures and minor phases of eleven
cobalt-base high-temperature alloys (rolled, cast,
and high-carbon Stellite 21, 422-19, X-63, 6059, 61,
X-40, S-816, 1-336, and J). The minor phases TaC,
NbC, Cr3C2, Cr7C3, Cr23C6, MgC, Cr203 type
oxides, spinels, and sigma were identified by X-ray
diffraction analysis. Sigma phase patterns appeared
strongest where large numbers of carbides were also
present, indicating that carbide precipitation may
facilitate sigma phase formation. The most preva-
lent carbide indicated was Cr23C6. One of the two
phases of the pearlitic structure consisted pre-
dominantly of the carbide Cr23C6.


NACA TN 3111

FRICTION AND WEAR INVESTIGATION OF
MOLYBDENUM DISULFIDE. II EFFECTS OF
CONTAMINANTS AND METHOD OF APPLICATION.
Marshall B. Peterson and Robert L. Johnson.
March 1954. 19p. diagrs., photos., tab. (NACA
TN 3111)









NACA
RESEARCH ABSTRACTS NO. 60

An experimental study was conducted using a low-
speed kinetic -friction apparatus to show the effects of
method of application and contaminants on the lubri-
cating characteristics of molybdenum disulfide MoS2.
Friction coefficients for a purified grade of MoS2 can
vary from 0.025 to 0.12 merely by changing the
method of application. Contaminants present in
commercial grades of MoS2 do not increase friction
but can (for example, 0.5 percent silica) adversely
affect wear. In room atmosphere, small amounts of
oil (5 to 10 percent) reduce friction below that ob-
tained with either purified MoS2 or with oil alone. At
least 10 percent MoS2 should be present in the oil to
obtain the lowest friction. The lowest friction values
were obtained at the highest temperatures used
(3000 F) where the adverse effects of moisture were
minimized.



NACA TN 3112

ANALOG STUDY OF INTERACTING AND NON-
INTERACTING MULTIPLE-LOOP CONTROL
SYSTEMS FOR TURBOJET ENGINES. George J.
Pack and W. E. Phillips, Jr. March 1954. 33p.
diagrs., photos. (NACA TN 3112)

An analog investigation of several turbojet control
configurations was made. Both proportional and
proportional-plus integral controllers were studied,
and compensating terms for engine interaction were
added to the control system. Data were taken on the
stability limits and the transient responses of these
various configurations. Analytical expressions in
terms of the component transfer functions were
developed for the configurations studied and the
optimum form for the compensation terms was de-
termined. It was found that the addition of the in-
tegral term, while making the system slower and
more oscillatory, was desirable in that it made the
final values of the system parameters independent of
source of disturbance and also eliminated droop in
these parameters. Definite improvement in system
characteristics results from the use of proper com-
pensation terms. At comparable gain points the
compensated system is faster and more stable.
Complete compensation eliminates engine interaction
permitting each loop to be developed to an optimum
point independently.



NACA TN 3126

A DESIGN STUDY OF LEADING-EDGE INLETS FOR
UNSWEPT WINGS. Robert E. Dannenberg.
March 1954. 56p. diagrs., photos., 3 tabs.
(NACA TN 3126. Formerly RM A9KO2b)

A method is presented for calculating the profile co-
ordinates for an inlet to be placed in the leading edge
of an airfoil from formulas. The method includes an
application of the principles of thin-airfoil theory
which permits the change in velocity distribution
caused by a variation in inlet profile to be calculated.
Wind-tunnel tests of leading-edge inlets in an airfoil
having the NACA 631-012 section were made to
evaluate the effects of the inlets on the aerodynamic
characteristics of the airfoil. The results indicated


5

that the airfoil with an inlet devised by the design
method had satisfactory aerodynamic characteristics.


NACA TN 3127

THE EFFECTIVENESS AT HIGH SUBSONIC MACH
NUMBERS OF A 20-PERCENT-CHORD PLAIN
TRAILING-EDGE FLAP ON THE NACA 65-210 AIR-
FOIL SECTION. Louis S. Stivers, Jr. March 1954.
15p. diagrs. (NACA TN 3127)

The lift-control characteristics of a 20-percent-
chord plain trailing-edge flap on the NACA 65-210
airfoil section have been analyzed for Mach numbers
from 0.30 to 0.875 utilizing section lift-coefficient
data. In addition, the relative merits of the plain
flap, a spoiler, and a dive-recovery flap employed
separately as a lift-control device on the NACA
65-210 airfoil section have been determined from
increments of section lift, drag, and pitching-
moment coefficients which accompanied the deflec-
tion of each control device. The Reynolds number
of the data varied with Mach number from about
1 x 106 to 2 x 106.


NACA TN 3129

INVESTIGATION OF A SLAT IN SEVERAL DIFFER-
ENT POSITIONS ON AN NACA 64A010 AIRFOIL
FOR A WIDE RANGE OF SUBSONIC MACH NUM-
BERS. John A. Axelson and George L. Stevens.
March 1954. 35p. diagrs., photos., 7 tabs. (NACA
TN 3129)

An investigation of a slat in several different posi-
tions on an NACA 64A010 airfoil has been conducted
over a Mach number range from 0.25 to 0.85,
corresponding to a Reynolds number range from
3.4 million to 8.1 million. Section force coefficients
and chordwise distributions of pressure and result-
ant loading are presented for several different loca-
tions of the slat. The loading on the slat rather
than the effects of the air flowing through the gap
was found to be the primary factor determining slat
performance.


NACA TN 3143

EXPERIMENTAL DETERMINATION OF THERMAL
CONDUCTIVITY OF LOW-DENSITY ICE. Willard D.
Coles. March 1954. 12p. diagrs., photo. (NACA
TN 3143)

The thermal conductivity of low-density ice has been
computed from data obtained in an experimental in-
vestigation of the heat transfer and mass transfer by
sublimation for an iced surface on a flat plate in a
high-velocity tangential airstream. The results are
compared with data from several sources on the
thermal conductivity of packed snow and solid glaze
ice. The results show good agreement with the
packed-snow values, and the extension of the curves
for packed snow to the solid ice regime indicates
that the curves are applicable to ice over the entire
density range.











NACA TN 3162

EFFECTS OF SUBSONIC MACH NUMBER ON THE
FORCES AND PRESSURE DISTRIBUTIONS ON FOUR
NACA 64A-SERIES AIRFOIL SECTIONS AT ANGLES
OF ATTACK AS HIGH AS 280. Louis S. Stivers, Jr.
March 1954. 145p. diagrs., photos., 8 tabs.
(NACA TN 3162)

A high-speed wind-tunnel investigation has been made
of the NACA 64A010, 64A410, 64A006, and 64A406
airfoil sections at angles of attack as high as 280.
Pressure-distribution, lift, drag, and moment char-
acteristics were determined for each airfoil section
at Mach numbers ranging from 0.30 to about 0.93,
with corresponding Reynolds numbers varying from
approximately 0.9 x 100 to 1.9 x 106. The a = 0.8
(modified) mean line was employed for the cambered
airfoil sections.


NACA TN 3164

FURTHER STUDIES OF THE MECHANISM BY
WHICH HYDROGEN ENTERS METALS DURING
CHEMICAL AND ELECTROCHEMICAL PROCESS-
ING. L. D. McGraw, W. E. Ditmars, C. A.
Snavely and C. L. Faust, Battelle Memorial
Institute. March 1954. 37p. diagrs., 4 tabs.
(NACA TN 3164)

This investigation was a continuation of efforts to
develop fundamental concepts which would be useful
in preventing or alleviating hydrogen damage to steel.
NACA Technical Note 2696 presented a new mecha-
nism which postulates that the entry of hydrogen into
metals from chemical and electrochemical action
occurs when hydrogen-metal alloy formation is
simultaneous with discharge (or release) of hydrogen
atoms. In the present work the phenomena relating
to hydrogen entry into steel were studied further.
In general, the results support the newly postulated
concepts.


NACA TN 3167

THERMAL CONDUCTANCE OF CONTACTS IN AIR-
CRAFT JOINTS. Martin E. Barzelay, Kin Nee Tong
and George Hollo, Syracuse University. March 1954.
47p. diagrs., photos., 2 tabs. (NACA TN 3167)

Tests were conducted to determine the factors in-
fluencing the thermal conductance across the inter-
face between 75S-T6 aluminum-alloy and AISI Type
416 stainless-steel structural joints. From the re-
sults it was concluded that (1) the thermal conduct-
ance of the interface joint increases with mean tem-
perature level, while it remains approximately
constant with changes in heat flow; (2) thin foils of
good conducting materials inserted between the in-
terfaces improve the heat transfer noticeably;
(3) common strength-giving bonding materials pro-
duce joints with very poor thermal conducitivit; and
(4) none of the three modes of heat transfer (metal-
to-metal conduction, air-film conduction, and radia-
tion) has any predominance over another across the
interface joints and, furthermore, there is an inter-
dependence among these three which has not pre-
viously been recognized.


NACA
RESEARCH ABSTRACTS NO.60


NACA TN 3177

ION TRACER TECHNIQUE FOR AIRSPEED MEAS- *
UREMENT AT LOW DENSITIES. W. B. Kunkel and
L. Talbot, University of California. March 1954.
31 p. diagrs. (NACA TN 3177)

A study has been made of the aerodynamic and pro-
duction detection problems associated with ion tracer
velocity measurement techniques, with particular
emphasis on those aspects unique to low-density gas
dynamics. A critical survey was made of the various
techniques which have been employed and specific
suggestions are offered relative to the successful use
of ion tracer velocity measuring methods at low
densities. A description is also included of some ex-
perimental work carriedout with an ion-pulse air-
speed indicator developed by the Ames Aeronautical
Laboratory Low Pressures Group of the National
Advisory Committee for Aeronautics for use in low-
density wind tunnels.


NACA TN 3190

FATIGUE INVESTIGATION OF FULL-SCALE
TRANSPORT-AIRPLANE WINGS. SUMMARY OF
CONSTANT-AMPLITUDE TESTS THROUGH 1953.
M. J. McGuigan, Jr., D. F. Bryan and R. E. Whaley.
Appendix A. NOTES ON THE USE OF BONDED
WIRES TO DETECT FATIGUE CRACKS. M. H.
Levin. March 1954. 45p. diagrs., photos., 3 tabs.
(NACA TN 3190)

Results are presented of constant-amplitude fatigue
tests on the wings of C-46 airplanes. Eight complete
wings were tested at four alternating load levels
ranging from 7-1/2 to 22 percent of the design ulti-
mate load factor. All tests were conducted with a
1 g mean load, which is about 22 percent of the de -
sign ultimate load factor. All failures which
occurred are classified in five types according to the
structural stress raisers in which they originated.
Effective stress-concentration factors were deter-
mined for each stress raiser Where failures
occurred, the rate and manner of fatigue-crack
propagation was investigated, and the effect of the
magnitude of load on these items was determined.
The scatter in fatigue life of the wings was analyzed
statistically. The load-lifetime relationship of the
test structure was compared with that of several
other full-scale and component structures which have
been subjected to fatigue tests. An appendix by M. H.
Levin presents information on the use of bonded
wires to detect small fatigue cracks; another appen-
dix deals with the use of fiber glass as a method of
structural repair.


NACA RM 53L22

ADDITIONAL FATIGUE TESTS ON EFFECTS OF
DESIGN DETAILS IN 355-T6 SAND-CAST
ALUMINUM ALLOY. I. D. Eaton and John A. Youra,
Aluminum Company of America. March 1954.
24p. diagrs., photos., 5 tabs. (NACA RM 53L22)

Additional static and fatigue tests were made on
aluminum-alloy 355-T6 sand-cast specimens. Direct
stress fatigue tests were made on plate-type spect-







NACA
RESEARCH ABSTRACTS NO.60

mens with a single 1-inch-diameter as-cast cored
hole and on specimens in which the cored hole was
reamed to 1 -1/16 inch diameter. In addition, direct-
stress fatigue tests were made on 0.300-inch-
diarrmeter specimens, with various degrees of porosity,
machined from the butt ends of plate-type specimens.
Comparisons are made with results of earlier tests,
on plate-type specimens with variations in design
details such as bosses and ribs, given in NACA
Technical Note 2394.



NACA RM E53J30

EFFECT OF ICE FORMATIONS ON SECTION DRAG
OF SWEPT NACA 63A-009 AIRFOIL WITH PARTIAL-
SPAN LEADING-EDGE SLAT FOR VARIOUS MODES
OF THERMAL ICE PROTECTION. Uwe H. von Glahn
and Vernon H. Gray. March 1954. 59p. diagrs.,
photos. (NACA RM E53J30)

Studies were made to determine the effect of ice
formations on the section drag of a 6.9-foot-chord
360 swept NACA 63A-009 airfoil with partial-span
leading-edge slat. In general, the icing of a thin
swept airfoil will result in greater aerodynamic
penalties than for a thick unswept airfoil. Glaze-ice
formations at the leading edge of the airfoil caused
large increases in section drag even at a liquid-water
content of 0.39 gram per cubic meter. The use of an
ice-free parting strip in the stagnation region caused
a negligible change in drag compared with a com-
pletely unheated airfoil. Cyclic de-icing when
properly applied caused the drag to decrease almost
to the bare-airfoil drag value.


NACA RM E53K24

KINETIC STUDY OF MASS TRANSFER BY SODIUM
HYDROXIDE IN NICKEL UNDER FREE-
CONVECTION CONDITIONS. Don R. Mosher and
Robert A. Lad. March 1954. 14p. diagrs.,
photo., tab. (NACA RM E53K24)

An investigation was conducted using static capsules
fabricated from "L" nickel tubing to determine the
effect of temperature level, temperature gradient,
and test duration on corrosion and mass transfer by
molten sodium hydroxide under free-convection con-
ditions. A base temperature range from 10000 to
16000 F with temperature differences to 5000 was
studied. The rate of mass transfer was found to be
strongly dependent on both temperature level and
gradient. The rate shows little tendency to decrease
for test durations up to 200 hours, although the con-
centration of nickel in the melt approaches a limiting
value after 100 hours.


NACA RM E53L21

PRELIMINARY INVESTIGATION OF THE "FREEZE-
CASTING" METHOD FOR FORMING REFRACTORY
POWDERS. W. A. Maxwell, R. S. Gurnick and A.
C. Francisco. March 1954. 19p. diagrs.,
photos., 2 tabs. (NACA RM E53L21)

A method of preparing intricately shaped objects
from refractory powders was investigated. The


7

method consists in preparing an extremely thick slip
with a small amount of binder, casting the slip into
a mold, and freezing to retain the shape of the cast-
ing. The casting is then dried by sublimation and
may subsequently be sintered by conventional means.
It was found possible to cast high-solid-content slips
by employing vibration during the casting process.
Turbosupercharger blades of good appearance and
free from radiographic flaws were produced. The
factors affecting the density of a casting before
sintering were determined.



NACA RM E53L21b

A FLOW CALORIMETER FOR DETERMINING
COMBUSTION EFFICIENCY FROM RESIDUAL
ENTHALPY OF EXHAUST GASES. Albert Evans
and Robert R. Hibbard. March 1954. 21p.
diagrs., 2 tabs. (NACA RM E53L21b)

A flow calorimeter for determining the combustion
efficiency of turbojet and ram-jet combustors from
measurement of the residual enthalpy of combustion
of the exhaust gas is described. Briefly, the
calorimeter catalytically oxidizes the combustible
constituents of exhaust-gas samples, and the result-
ant temperature rise is measured. This tempera-
ture rise is related to the residual enthalpy of com-
bustion of the sample by previous calibration of the
calorimeter. Combustion efficiency can be calcu-
lated from a knowledge of the residual enthalpy of the
exhaust gas and the combustor input enthalpy. An
accuracy of t0.2 Btu per cubic foot was obtained with
prepared fuel-air mixtures, and the combustion
efficiencies of single turbojet combustors measured
by both the flow-calorimeter and heat-balance
methods compared within 3 percentage units. Flow
calorimetry appears to be a suitable method for
determining combustion efficiencies at high combus-
tor temperatures where ordinary thermocouples can-
not be used. The method is fundamentally more
accurate than heat-balance. methods at high combus-
tion efficiencies and can be used to verify near-100-
percent efficiency data.





BRITISH REPORTS


N-28582*

Forest Products Research Lab. (Gt. Brit.)
TRIALS OF TIMBERS FOR PLYWOOD MANUFAC-
TURE. AGBA GOSSWEILERODENDRON
BALSAMIFERUM-HARMS NIGERIA. (32 POUNDS
PER CUBIC FOOT AT 15 PER CENT MOISTURE
CONTENT) PROGRESS REPORT TWENTY-THREE.
October 1953. 14p. 6 tabs. (Forest Products
Research Lab.)

Average quality logs of Agba were selected and
tested to provide comparable data with those of
Khaya and Sapele. Results of processing are given.
Characteristics are presented of the veneer and
finally the potentialities of Agba for plywood manu-
facture are given.









N-28777*

Aeronautical Research Council (Gt. Brit.)
THE LOSS IN CLIMB PERFORMANCE, RELATIVE
TO THE OPTIMUM, ARISING FROM THE USE OF A
PRACTICAL CLIMB TECHNIQUE. K. J. Lush.
1953. 12p. diagrs., 2 tabs. (ARC R & M 2756;
ARC 12,563. Formerly AAEE/Res/243)

A practical climb technique will not in general com-
ply with the condition for optimum climb performance
and will give an inferior climb. An assessment of
the loss of performance involved is, therefore, desir-
able. A practical climb technique is considered
which is defined by a fixed relation between equiva-
lent air speed (or Mach number) and pressure alti-
tude, and a rough estimate made of the loss in per-
formance involved in using such a technique with a
turbine jet aircraft over a range of air temperature,
engine speed, thrust, or aircraft weight. An approxi-
mate method of calculating a suitable relation is
given in an appendix. If the technique for optimum
climb is not fixed by compressibility effects, use of
such a practical climb technique will result in a loss
of performance, relative to the optimum, less than the
greater of 1 percent and 1/2 ft/sec in rate of climb
over a wide range of aircraft weight or a moderate
range of air temperature, engine speed or thrust.
Approximate limits are quoted in table 2. More pre-
cise limits may be estimated for any particular air-
craft. If the technique for optimum climb is deter-
mined by compressibility effects such a practical
climb technique can give optimum performance over
a wide range of weight, air temperature, and engine
speed.



N-28778*

Aeronautical Research Council (Gt. Brit.)
THE ELASTIC STABILITY OF SANDWICH PLATES.
J. H. Hunter-Tod. 1953. 39p. diagrs. (ARC
R Ez M 2778; ARC 12,550. Formerly College of
Aeronautics, Cranfield, Rept. 25)

This paper treats the elastic stability of supported
rectangular plates of sandwich construction with iso-
tropic and aeolotropic fillings under compression and
shear loading. Formulas are developed for critical
stresses for flat and curved panels in compression
and flat panels in shear for the buckling of the whole
panel, also for the wrinkling or local failure of the
faces of flat panels in compression. It is established
that for a wide range of conditions the critical stress
for panels buckling in compression is independent of
the form of the filling providing it is symmetrical
about the normal; of the elastic constants of the fill-
ing only the transverse shear is of concern. As a
result a simple extension of the equivalent plate
theory of greatly improved accuracy is developed
enabling the use of equations treating the plate as a
whole.



N-28779*

Aeronautical Research Council (Gt. Brit.)
THE TURBULENT BOUNDARY LAYER IN COM-
PRESSIBLE FLOW. W. F. Cope. 1953. 8p. diagrs.,
tab. (ARC R & M 2840; ARC 7634 (rev.). Formerly
Nat. Piyti'al Lab., Engineering Dept. rept.)


NACA
RESEARCH ABSTRACTS NO.60

The flow of a compressible gas past a flat plate is in-
vestigated for a turbulent boundary layer. TheJ local
and mean skin-friction coefficients are calculated for
both power and log laws of velocity distribution. The
calculations show a considerable reduction of both co-
efficients with increasing. M. In the course of the
analysis, assumptions have been made whose accura -
cy is not proven, though they are consistent with
those made in incompressible gas dynamics. The re-
sults are applied to calculate the contribution to fR
of skin friction for a typical projectile of various
calibers. The calculation shows that it should be
possible by a properly selected series of wind-tunnel
and full-scale experiments to ascertain if the large
reduction in skin friction occurs, but that it is un-
likely that it will be possible to discriminate between
the two hypotheses about velocity distribution.



N-28780*

Aeronautical Research Council (Gt. Brit.)
FOUR STUDIES IN THE THEORY OF STRESS CON-
CENTRATION. H. L. Cox. January 1950. ii, 58p.
diagrs., 9 tabs. (ARC R & M 2704. Formerly Nat.
Physical Lab., Engineering Div. Repts. 359 48;
361/48; 360/48; 362/48; 444A/50)

The four papers comprised in this monograph are a
study of some of the theoretical aspects of experi-
mental work in progress in the National Physics
Laboratory from 1937 to 1947. The greater part of
the work is related to failure of materials by fatigue
and chief attention is paid to this mode of failure.
Parts II and IV deal with the development of means to
compute the stress distribution in the neighborhood
of holes, grooves, and fillets. Part I is mainly con-
cerned with the effect of holes and internal flaws.
Part III deals with the effect of surface irregularities
on fatigue strength.



N-28781*

Aeronautical Research Council (Gt. Brit.)
A THEORETICAL APPROACH TO THE DESIGN OF
HYDROFOILS. C. H. E. Warren. 1953. 20p.
diagrs., 5 tabs. (ARC R & M 2836; ARC 10,181.
Formerly RAE Tech. Note Aero 1739; Tech.Note
Aero 1826)

An investigation has been made into the application of
the theory of thin sections to the design of hydrofoils
having high cavitation speeds. Consideration is given
to both symmetrical sections, which themselves are
suitable for struts, and camber-lines, which, when
used with the symmetrical sections, lead to cambered
sections which are suitable for lifting surfaces. In
all the aim has been to keep the peak local velocities
to a minimum and the sections developed differ from
"low-drag" airfoil sections mainly in that, being hy-
drofoils, the sections have sharp leading edges. The
theoretical optimum section consists of an elliptic
symmetrical section superimposed on a logarithmic
camber-line. Typical practical sections will cavuate
at a speed lower by about 5 knots than the theoretical
optimum section of the same thickness/chord ratio
and at the same lift coefficient. For strut sections, it
is shown that sections having high cavitation speeds
at zero incidence tend to be inferior to other sections
at incidences as small as 20. For lifting surface







NACA
RESEARCH ABSTRACTS NO.60

sections it is shown thai although a high cavitation
speed demands a low design lift coefficient, a high
loading at cavitation demands a high design lift
coefficient. Operation above cavitation speeds or
over wide ranges of lift coefficient is not considered.



N-28782'

Aeronautical Research Council (Gt. Brit.)
WIND-TUNNEL TESTS ON THE PREVENTION OF
BOUNDARY-LAYER SEPARATION BY DISTRIBUTED
SUCTION AT THE REAR OF A THICKAEROFOIL
(NPL 153). N. Gregory, R. C. Pankhurst and W. S.
Walker. 1953. 7p. diagrs., tab. (ARC R & M 2788.
Formerly ARC 13,446, Peri. 702; FM 1485)

Tests of a preliminary nature have been carried out
on a 33-percent-thick symmetrical airfoil (NPL 153)
with suction through a porous-surlace from 0.80
chord to the trailing edge, which was rounded and
fitted with a Thwaites flap. The distributed suction
was found to prevent separation and to reduce the
wake drag to zero. The overall effective drag (in-
cluding an allowance for the power required for the
suction) was reduced slightly, but still remains fairly
high. No hysteresis was observed in the change of
drag with suction quantity. The flap was essential to
stabilize the flow: without it, the flow with suction
was unsteady and the wake drag was appreciable.
When the flap was deflected 200, there was no in-
crease in the suction quantity required to prevent
separation.



N-28783*

Aeronautical Research Council (Gt. Brit.)
NOTE ON AERODYNAMIC CAMBER. H. C. Garner.
1953. 14p. (ARC R .- M 2820. Formerly ARC
13,092; S .', C 2391; Perf. 656)

An explanation is given of the theoretical significance
of camber derivatives. The various available
methods of making experimental measurements with
particular reference to the use of a curved-flow tun-
nel are discussed. There is particular need for
systematic information about the influence of curva-
ture of flow on control hinge-moments as a step
towards the understanding of three-dimensional
viscous flow.



N-28784*

Aeronautical Research Council (Gt. Brit.)
NOTE ON THE USE OF THE THREE-DIMENSIONAL
SHOCK-WAVE RECORDER FOR STUDYING INTER-
FERENCE IN A SUPERSONIC WIND TUNNEL. A. 0.
Ormerod. 1953. 9p. diagrs., photo. (ARC R & M
2798; ARC 13.940. Formerly RAE Tech. Note Aero
2088)

A description is given of the shock-wave recorder
which has been used to investigate wind-tunnel inter-
ference on a sting-mounted wing having 500 of
sweepback. Diagram of the shock-wave patterns
round the wing is given for Mach numbers 1.4, 1.6,
and 1.8 and angles of attack of 0o and 40.


9

N-2878e

Aeronautical Research Council (Gt. Brit.)
NATURAL FREQUENCIES AND MODES OF A
MODEL DELTA AIRCRAFT. D. R. Gaukroger.
1953. 32p. diagrs., tab. (ARC R & M 2762; ARC
13,377. Formerly RAE Structures 75)

Resonance tests on a model delta wing are described.
Consideration is given to the effect of inertia distri-
bution on the first three normal symmetric modes of
vibration. The mean center-of-gravity position,
fuselage pitching moment of inertia and wing inertia
axis have been independently varied, and the effect of
concentrated tip masses has been examined. Re-
sults are given which are intended as a general guide
in flutter calculations.



N-28854*

Royal Aircraft Establishment (Gt. Brit.)
A SIMPLE METHOD OF PROVIDING AUTOMATIC
ZERO ADJUSTMENT IN A POSITION-CONTROL
SERVOMECHANISM EMPLOYING A D.C.
AMPLIFIER. L. A. J. Lawrence. October 1953.
17p. diagrs. (RAE Tech.Note GW 280)

A system is described for the removal of accumu-
lated drift from the output of a position-control
servomechanism employing a d-c amplifier. The
factors governing the accuracy of the zero at the
instant of adjustment and its subsequent accuracy are
both discussed, together with practical results and
circuit details.


N-28855*

Royal Aircraft Establishment (Gt. Brit.)
ON THE LAMINAR BOUNDARY LAYER SEPARA-
TION FROM THE LEADING EDGE OF A THIN
AEROFOIL. P. R. Owen and L. Klanfer. October
1953. 19p. diagrs., 6 tabs. (RAE Aero 2508)

Low-speed wind tunnel tests have shown that when a
laminar boundary layer separates from the leading
edge of a thin airfoil at angle of attack, the flow often
becomes attached to the surface again some distance
downstream. It is suggested that the length of the
"bubble" depends primarily on the Reynolds number
based on the displacement thickness at the separation
point. This Reynolds number in turn depends on the
distance of the velocity peak on the upper surface of
the airfoil from the stagnation point and it is inferred
that, at a Reynolds number based on the chord, a long
bubble is more likely to occur when the velocity peak
is close to the stagnation point.


N-28856*

Aeronautical Research Council (Gt. Brit.)
TABULATION OF THE BLASIUS FUNCTION WITH
BLOWING AND SUCTION. H. W. Emmons and D. C.
Leigh. June 5, 1953. 81p. diagrs., 3 tabs. (ARC
15,966; FM 1913)

The present solutions were obtained in connection
with the solution of a combustion problem. The
Whole possible range of blowing and suction values is







10


covered in this paper. Calculations were done on
the Electronic Delay Storage Automatic Calculator
and the results are included in table form.



N-28858*

Aeronautical Research Council (Gt. Brit.)
LARGE SCALE ATMOSPHERIC FLOW PATTERNS
IN THE LABORATORY. T. V. Davies. May 5, 1953.
6p. diagr., photos. (ARC 15,876; FM 1896)

A brief description is given of laboratory apparatus
which simulates the large scale features of atmos-
pheric motion. Also given are principal results ob-
tained together with the explanation of the corre-
spondence between experimental flows and atmos-
pheric flows. The research work has been conducted
principally at the Department of Meteorology,
Chicago University, but more recently at other
meteorological departments in the U. S. A.


N-28935*

Aeronautical Research Council (Gt. Brit.)
SUMMARY OF THE THEORETICAL WORK DONE ON
THE STABILITY OF THIN PLATES, 1939 TO 1946.
D. M. A. Leggeti. 1953. 8p. (ARC R & M 2784.
Formerly ARC 13,366; Strut 1376)

Attention is drawn to the more important problems of
the stability of thin plates which were requiring solu-
tions at the beginning of the war, and progress made
towards their solution during the subsequent 7 years
is indicated. Three types of problems are discussed:
the critical buckling load of a flat rectangular plate
when the edges are not all simply supported, the post-
buckling behavior of a long flat plate under shear, and
the initial and post-buckling behavior of a curved
plate under various combinations of shear, compres-
sion, and normal pressure.



N-28968*

Royal Aircraft Establishment (Gt. Brit.)
TESTS ON THE RELATIVE EFFICIENCY OF
CHROMATE PIGMENTS IN ANTI-CORROSIVE
PRIMERS. H. G. Cole. November 1953. 20p.
diagr., 7 tabs. (RAE Tech.Note Met. 185)

Seawater spray corrosion tests have been made on
two magnesium alloys, aluminum alloy, and mild
steel, painted with primers made from 18 chromate
pigments incorporated in turn in a litho-oil/
coumarone medium. Best all round protection was
given by zinc monoxy chromate, calcium chromate,
and strontium chromate, and good protection by
potassium zinc chrome (zinc yellow) and zinc tetroxy
chromate. Four complex cadmium chromes and
three lead chromates gave poor results. Of the zinc
and alkaline earth pigments, those giving best pro-
tection were of intermediate solubility.


NACA
RESEARCH ABSTRACTS NO.60


N-28969'
q.
Royal Aircraft Establishment (Gt. Brit.)
CRACK SENSITIVITY, SHEAR STRENGTH, CREEP
AND WATER ABSORPTION OF BIAX1ALLY
STRETCHED PERSPEX. A. S. Atkinson and W. W.
Wright. October 1953. 8p. diagrs., 3 tabs. IRAE
Tech.Note Chem. 1208)

Preliminary tests on samples oi biaxially stretched
polymethyl methacrylate have indicated that the
process reduces sensitivity to cracks, increases the
shear strength and reduces creep to an extent which
may have practical advantages. On the other hand
there is probably an increase in the maximum water
absorption.





UNPUBLISHED PAPERS


N- 12563*

National Bureau of Standards.
CORROSION OF ALUMINUM-ZINC-MAGNESIUM -
COPPER ALLOYS. Fred M. Reinhart.
December 15, 1951. (i), 19p. diagrs., photos., tab.
(National Bureau of Standards. Rept. 1334)

Aluminum-zinc -magnesium-copper alloys, clad and
unclad, anodized and unanodized, were exposed in
marine environments to determine their corrosion
behavior, and for comparison, specimens of anodized
aluminum-copper-magnesium alloys, clad and un-
clad, were also exposed. Results from this experi-
ment are presented in this report.


N-15972

A NEW METHOD IN THE DYNAMICS OF A VISCOUS
FLUID. (Novyi Metod v Dinamike Vyazkoi Zhidkosti).
V. G. Nevzglyadov. 7p. (Trans. from Akademiia
NaukSSSR, Doklady, v.77, no.4, 1951, p.573-576)

The velocity vector of an incompressible fluid is
written as the sum of two vectors; one satisfies the
equation of potential flow, the other is small com-
pared with the first. The flow equation is then ob-
tained by replacing the velocity vector in the Navier-
Stokes equation by the sum of these two vectors and
neglecting products of the additional velocity vector
and its derivatives. The resulting linear equation for
the unknown additional velocity vertor reduces to
Oseen's when the vector obtained from the solution of
the potential flow problem is replaced by the velocity
vector very far from the body. The equation for the
additional velocity vector is not solved; but it is
assumed that, on a streamline near the body, the
components of the additional velocity vector and their
derivatives are determined by a polynomial approxi-
mation to the velocity components that is valid from
this streamline to the surface of the body.







NACA
RESEARCH ABSTRACTS NO. 60

N-27945'

National Bureau of Standards.
ZINC AND CADMIUM PLATED FASTENERS ON
ALCLAD 75S-T6 ALUMINUM ALLOY. Fred M.
Reinhart and David B. Ballard. May 6, 1953. ii,
23p. photos., 2 tabs. (National Bureau of
Standards. Rept. 2477)

This initial progress report contains the results
after 9 months of exposure in tidewater, 12 months
in marine and urban atmospheres. It is tentatively
concluded that the galvanic corrosion with cadmium
plated steel fasteners would be less damaging to
Alclad 75S-T6 aluminum alloy than would that with
zinc plated steel fasteners.



N-29104*

Cornell University, Graduate School of Aeronautical
Engineering. ON THE RELATION AMONG STRESS,
STRAIN, VELOCITY FROM TESTS ON COPPER
WIRES SUBMITTED TO LONGITUDINAL IMPACT.
C. Riparbelli. July 1953. (Rev.) 82p. diagrs.,
photos. (Cornell University, Graduate School of
Aeronautical Engineering)

The relation among stress, strain and time rate of
strain is found by experiments of tensile impact on
copper wires. The results agree with the hypothesis
that the velocity of propagation of a small disturbance
is the same, whether the material is strained
entirely within the elastic range or whether the dis-
turbance is introduced and propagated in the
presence of plastic flow. Results indicate that the
rate of plastic flow is proportional to the excess of
the strain.



N-29362'

DEGREE OF APPROXIMATION OBTAINED BY
ENERGY METHODS IN CALCULATING EIGEN-
VALUES. (Sull'Approssimazione dei procedimenti
energetic per it calcolo di autovalori). Ottorino
Sesini. February 1954. 15p. diagr. (Trans. from
Onore di Modesto Panetti, 1950, p. 94-99)

A critical examination is made of the energy methods
for the approximate calculation of the eigenvalues in
engineering problems. The methods used by Bryan-
Timoshenko in his calculations of critical loads and
those used by Lord Rayleigh or Stodola in calculating
the natural frequency of vibrating elastic systems or
the speed of rotating shafts are considered.





MISCELLANEOUS


N-27708*


AERODYNAMICS THEORY, EXPERIMENT,
APPLICATION. Hugh L. Dryden. 9p. diagrs.,
photos. (Reprint from Aeronautical Engineering
Review, v. 12, no. 12, December 1953).


11

Typical examples from various time periods in the
growth of aerodynamics in the first half-century of
flight are given. For clarity, theory, experiment,
and application are treated as separate lines of
effort. Today the term aerodynamics is applied to
this triplet of activities, which, starting as separate
and almost distinct threads, are now :horoughly in-
terwoven into the fabric of modern aerodynamics.
The great strength of aerodynamics and aeronautical
engineering lies in the close integration and team-
work of the three groups within the last 20 or 25
years.


N-3074C


INDEX OF NACA TECHNICAL PUBLICATIONS.
JUNE, 1951 MAY, 1953. 1953. viii, 230p.
(NACA)

There is a classified listing of subject categories; a
chronological listing of NACA publications under each
subject category; an alphabetical index to the subject
categories; and an author index.


NACA Rept. 1127

Errata No. 1 on "ONE-DIMENSIONAL ANALYSIS OF
CHOKED-FLOW TURBINES." Robert E. English
and Richard H. Cavicchi. 1953.


NACA RM 54A04

Errata No. 1 on "EFFECTS OF MOLECULAR
WEIGHT ON CRAZING AND TENSILE PROPERTIES
OF POLYMETHYL METHACRYLATE. I. Wolock,
M. A. Sherman and B. M. Axilrod. February 17,
1954.




DECLASSIFIED NACA REPORTS


NACA RM L51F04

HYDRODYNAMIC DIRECTIONAL BEHAVIOR OF A
SWEPT PLANING-TAIL HULL. Donald D.
Arabian. January 10, 1952. 15p. diagrs.
(NACA RM L51F04) (Declassified from
Confidential, 3/9/54)

A qualitative investigation of the low-speed direc-
tional behavior of a swept planing-tail hull was made
in the Langley tank no. 2 in still water and still air
with the use of a free self-propelled model. The
configuration was directionally unstable over a range
of low speed. It was, however, directionally con-
trollable at all speeds by use of the rudder and ele-
vator. Several modifications that were investigated
did not improve the controllability.


THE FOLLOWING REPORT
HAS BEEN DECLASSIFIED
FROM CONFIDENTIAL, 3/10/54.

RM L9J20


NACA-Langley 3-30-54 4M




UNIVERSITY OF FLORIDA
61 0UM
53 092




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