Research abstracts

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Title:
Research abstracts
Physical Description:
93 v. : ; 27 cm.
Language:
English
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United States -- National Advisory Committee for Aeronautics
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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 )
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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:
AA00009235:00089

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National Avisory Committee ror Aeronautics


N0.281


Research Abstracts


SEPTEMBER 3, 1952


CURRENT NACA REPORTS


NACA Rept. 1049. *

SPECTRA AND DIFFUSION IN A ROUND TURBU-
LENT JET. Stanley Corrsin and Mahinder S. Uberoi.
1951. ii, 21p. diagrs., photos. (NACA Rept. 1040.
Formerly TN 2124)

In a round turbulent jet at room temperature, meas-
urement of the shear correlation coefficient as a
function of frequency (through band-pass filters) has
given a rather direct verification of Kolmogroff's
local-isotropy hypothesis. One-dimensional power
spectra of velocity and temperature fluctuations,
measured in unheated and heated jets, respectively,
have been contrasted. Under the same conditions,
the two corresponding transverse correlation func-
tions have been measured and compared. Measure-
ments have been made of the mean thermal wakes
behind local (line) heat sources in the unheated turbu-
lent jet, and the order of magnitude of the tempera-
ture fluctuations has been determined.


NACA Rept. 1048

A STUDY OF EFFECTS OF VISCOSITY ON FLOW
OVER SLENDER INCLINED BODIES OF REVOLU-
TION. H. Julian Allen and Edward W. Perkins.
1951. ii, 13p. diagrs., photos. (NACA Rept. 1048.
Formerly TN 2044)

The observed flow field about slender inclined bodies
of revolution is compared with the calculated charac-
teristics based upon potential theory. The compari-
son is instructive in indicating the manner in which
the effects of viscosity are manifest. Based on this
and other studies, a method is developed to allow for
viscous effects on the force and moment characteris-
tics of bodies. The calculated force and moment
characteristics of two bodies of high fineness ratio
are shown to be in good agreement, for most engi-
neering purposes, with experiment.



NACA Rept. 1051

AN ANALYSIS OF BASE PRESSURE AT SUPERSONIC
VELOCITIES AND COMPARISON WITH EXPERI-
MENT. Dean R. Chapman. 1951. ii, 23p. diagrs.,
photos. (NACA Rept. 1051. Formerly TN 2137)

The pressure on the base of an object travelling at
supersonic velocity is investigated for both two-


dimensional and axially-symmetric bodies. Inviscid-
fluid flow is analyzed first and the result obtained
that a strictly inviscid-fluid theory is not satisfactory.
An approximate semiempirical theory for the base-
pressure flow in a viscous fluid is then developed
from a correlation of certain experiment data.


NACA Rept. 1055

COMPARISON OF THEORETICAL AND EXPERI-
MENTAL HEAT-TRANSFER CHARACTERISTICS OF
BODIES OF REVOLUTION AT SUPERSONIC SPEEDS.
Richard Scherrer. 1951. ii, 15p. diagrs., photo.
(NACA Rept. 1055. Formerly RM A8L28; TN 1975;
TN 2087; TN 2131; TN 2148)

An investigation of the three important factors that
determine convective heat-transfer characteristics at
supersonic speeds, location of boundary-layer transi-
tion, recovery factor, and heat-transfer parameter
has been performed at Mach numbers from 1. 49 to
2. 18. The bodies of revolution that were tested had,
in most cases, laminar boundary layers, and the test
results have been compared with available theory.
Boundary-layer transition was found to be affected by
heat transfer. Adding heat to a laminar boundary
layer caused transition to move forward on the test
body, while removing heat caused transition to move
rearward. These experimental results and the im-
plications of boundary-layer-stability theory are in
qualitative agreement. Theoretical and experimental
values of the recovery factor, based on the local Mach
number just outside the boundary layer, were found to
be in good agreement for both laminar and turbulent
boundary layers on both of the body shapes that were
investigated. In general, values of the heat-transfer
parameter (Nusselt number divided by the square root
of the Reynolds number) as determined for both heated
and cooled cones with uniform and nonuniform surface
temperatures, were in good agreement with theory.
It was also found that the theory for cones could be
used to predict the values of heat-transfer parameter
for a pointed body of revolution with large negative
pressure gradients with good accuracy.


NACA TN 2747

CHARTS AND APPROXIMATE FORMULAS FOR THE
ESTIMATION OF AEROELASTIC EFFECTS ON THE
LATERAL CONTROL OF SWEPT AND UNSWEPT
WINGS. Kenneth A. Foss and Franklin W. Diederich.
July 1952. 70p. diagrs., 2 tabs. (NACA TN 2747)

Charts and approximate formulas are presented for
the estimation of static aeroelastic effects on the
spanwise lift distribution, rolling-moment coeffi-


*AVAILABLE ON LOAN ONLY.
ADDRESS REQUESTS FOR DOCUMENTS TO NACA, 1724 F ST., NW., WASHINGTON 25, D. C., CITING CODE NUMBER ABOVE EACH TITLE;
THE REPORT TITLE AND AUTHOR.







2


cient, and rate of roll due to aileron deflections on
swept and unswept wings at subsonic and supersonic
speeds. Some design considerations brought out by
the results of this paper are discussed


NACA TN 2751

A SIMPLE APPROXIMATE METHOD FOR CALCU-
LATING SPANWISE LIFT DISTRIBUTIONS AND AER-
ODYNAMIC INFLUENCE COEFFICIENTS AT SUB-
SONIC SPEEDS. Franklin W. Diederich. August
1952. 63p. diagrs., tab. (NACA TN 2751)

Several approximate methods for calculating lift dis-
tributions at subsonic speeds are combined and ex-
tended to form a simple step-by-step procedure for
calculating symmetric and antisymmetric lift distri-
butions on swept and unswept wings. The extension
of the method to the calculation of aerodynamic in-
fluence coefficients and of spanwise moment distribu-
tions is indicated.


NACA TN 2752

A STUDY OF THE STABILITY OF THE LAMINAR
BOUNDARY LAYER AS AFFECTED BY CHANGES IN
THE BOUNDARY-LAYER THICKNESS IN REGIONS
OF PRESSURE GRADIENT AND FLOW THROUGH
THE SURFACE. Neal Tetervin and David A. Levine.
August 1952. 83p. diagrs. tab. (NACA TN 2752)

Calculations made by the Schlichting method for the
computation of laminar-boundary-layer velocity pro-
files and the Lin method for the computation of their
critical Reynolds numbers demonstrate that in a re-
gion of fallir, pressure on an impervious surface an
increase in boundary-layer thickness can cause the
velocity profile shape to be (ha rxced enough by the in-
crease in effective pressure gradient so that the ratio
of the local critical Reynolds number to the local
boundary-layer Reynolds number is increased. Sim-
ilar effects occur when there is flow through the sur-
face; in this case the effects depend on the effective
flow through the surface as well as on the effective
pressure gradient. These calculations suggest that
the disturbing effect of roughness particles can be de-
creased by a sufficient increase in boundary-layer
thickness without a decrease in stability.



NACA TN 2753

EFFECTS OF MACH NUMBER VARIATION BE-
TWEEN 0.07 AND 0.34 AND REYNOLDS NUMBER
VARIATION BETWEEN 0.97 x 106 AND 8.10 x 106
ON THE MAXIMUM LIFT COEFFICIENT OF A
WING OF NACA 64-210 AIRFOIL SECTIONS. James
E. Fitzpatrick and William C. Schneider. August
1952. 34p. diagrs., photos., tab. (NACA TN 2753)

The effects of Mach number and Reynolds number on
the maximum lift coefficient of a wing of NACA
64-210 airfoil sections are presented. The wing was
tested with and without partial-span and full-span


NACA
RESEARCH ABSTRACTS N0.28


split flaps deflected 60. Peak maximum lift coeffi-
cients were measured at Mach numbers between 0.12
and 0.20, depending on the Reynolds number range
and flap configuration.



NACA TN 2755

ANALYSIS OF LANDING-GEAR BEHAVIOR.
Benjamin Milwitzky and Francis E. Cook. August
1952. 98p. diagrs., photo., 3 tabs. (NACA
TN 2755)

The behavior of the conventional oleo-pneumatic land-
ing gear during impact is analyzed. The applicability
of the analysis to actual landing gears is established
by comparing calculated results with drop-test data.
In addition to the more exact treatment, studies are
made to determine the effects of variations in such
parameters as the force-deflection characteristics of
the tire, the orifice discharge coefficient, and the
polytropic exponent for the air-compression process
in the shock strut, which may not be known accurately
in practical design problems. An investigation is
also made to determine the extent to which represen-
tation of the system can be simplified and still yield
useful results. Generalized solutions for the behav-
ior of a simplified system, which may be useful in
preliminary design, are presented for a wide range
of landing-gear and impact parameters.



NACA TN 2756

NOISE FROM INTERMITTENT JET ENGINES AND
STEADY-FLOW JET ENGINES WITH ROUGH BURN-
ING. Leslie W. Lassiter. August 1952. 21p.
diagrs. (NACA TN 2756)

Sound measurements were made on a pulse jet and a
subsonic ram jet of the types used for helicopter
rotor propulsion and on a turbojet with afterburner.
The pulse jet was found to produce a discrete fre-
quency spectrum in which the component correspond-
ing to the engine firing frequency was generally pre-
dominant. An analysis of pulse jet noise, based on
resonant-tube theory, is presented. The analysis
allows a reasonable estimate of the noise level, if
certain of the flow parameters of the engine are
known. The small subsonic ram jet and the turbojet
afterburner unit were found to produce discrete fre-
quency spectrums somewhat similar to that of the
pulse jet.


NACA TN 2757

EXPERIMENTAL STUDIES OF NOISE FROM SUB-
SONIC JETS IN STILL AIR. Leslie W. Lassiter and
Harvey H. Hubbard. August 1952. 35p. diagrs.,
photos., tab. (NACA TN 2757)

Experimental studies have been made of the noise
from a series of model subsonic jets ranging in di-
ameter from 0.75 to 12.0 inches and the results are
compared with data obtained for a turbojet engine.
The effects of such parameters as jet size, exit gas






NACA
RESEARCH ABSTRACTS N0.28


velocity, density, and turbulence level on the noise
generated in the mixing region of a jet are evaluated.
The velocity and turbulence level were found to have
the greatest effect on the noise intensities and the
frequency content was found to be a function of jet
size and the observer's location. The noise gen-
erated by the turbojet engine was found to be closely
related to that generated by simple model jets and an
empirical relation is given to allow the extrapolation
of available jet-noise data to other operating condi-
tions.


NACA TN 2758

WEAR AND SLIDING FRICTION PROPERTIES OF
NICKEL ALLOYS SUITED FOR CAGES OF HIGH-
TEMPERATURE ROLLING-CONTACT BEARINGS.
I ALLOYS RETAINING MECHANICAL PROPER-
TIES TO 600 F. Robert L. Johnson, Max A. Swikert
and Edmond E. Bisson. August 1952. 30p. diagrs.,
photos., 3 tabs. (NACA TN 2758)

Wear and sliding friction properties of a number of
nickel alloys operating against hardened SAE 52100
steel were studied. These alloys include "L" nickel,
wrought monel, cast monel, cast modified "H" monel,
cast "S" monel, Invar, Ni-Resist 3, and Nichrome V.
Some of the alloys studied may be useful as possible
cage material for high-temperature, high-speed bear-
ings for aircraft turbines or for bearings to operate
in corrosive media. Desirable operating properties
of all the materials could be associated with the de-
velopment on the rider surface of a naturally formed
film of nickel oxide. On the basis of wear and fric-
tion properties, Ni-Resist 3, modified "H" monel,
and Invar were the best materials studied in this in-
vestigation although they did not perform as well as
nodular iron. "L" nickel performed well with light
loads but was not effective at higher loads when the
surface film broke down.


NACA TN 2759

WEAR AND SLIDING FRICTION PROPERTIES OF
NICKEL ALLOYS SUITED FOR CAGES OF HIGH-
TEMPERATURE ROLLING-CONTACT BEARINGS.
II ALLOYS RETAINING MECHANICAL PROPER-
TIES ABOVE 600 F. Robert L. Johnson, Max A.
Swikert and Edmond E. Bisson. August 1952. 29p.
diagrs., photos., 3 tabs. (NACA TN 2759)

Wear and sliding friction properties of a number of
nickel alloys operating against hardened SAE 52100
steel were studied. The alloys were cast beryllium
nickel, heat-treated beryllium nickel, cast Inconel,
Nimonic 80, Inconel X, Refractalloy 26, and Discaloy.
Some of the alloys studied may be useful as material
for cages of rolling-contact bearings that operate at
high speeds with temperatures above 600 F in pro-
jected aircraft turbine engines or for bearings that
operate in corrosive mediums. Desirable operating
properties and the absence of extreme mass welding
of all the materials studied could be associated with
the development of the sliding surfaces of a naturally
formed film of nickel oxide. On the basis of wear
and friction properties, cast Inconel performed very
well in these experiments and compares favorably
with nodular iron. Nimonic 80 also showed promise
as a possible cage material.


3


NACA TN 2760

DERIVATION OF STABILITY CRITERIONS FOR
BOX BEAMS WITH LONGITUDINALLY STIFFENED
COVERS CONNECTED BY POSTS. Paul Seide.
August 1952. 21p. diagr. (NACA TN 2760)

An investigation has been made of the elastic stabili-
ty of an idealized box beam with longitudinally
stiffened covers connected by posts and subjected to
end moments and axial loads. Stability criterions
which give the axial stiffness of the posts required to
achieve desired stress values in the box-beam covers
are derived.


NACA TN 2761

INSTRUMENT-FLIGHT RESULTS OBTAINED WITH
A COMBINED-SIGNAL FLIGHT INDICATOR MODI-
FIED FOR HELICOPTER USE. Almer D. Crim,
John P. Reeder and James B. Whitten. August 1952.
13p. diagrs., photos. (NACA TN 2761)

A flight indicator which combines heading, altitude,
bank-angle, and pitch-attitude information was modi-
fied for helicopter use and evaluated by means of
instrument flights in a single-rotor helicopter. The
modifications consisted of adding fuselage-rate-of-
pitch signals to the instrument and increasing the
ratio between heading and bank signals. The com-
bined signal flight indicator enables the pilot to main-
tain more precise control of heading, altitude, and
airspeed and required less concentration than with
conventional instruments.


NACA TN 2764

ACCURACY OF APPROXIMATE METHODS FOR
PREDICTING PRESSURES ON POINTED NONLIFT-
ING BODIES OF REVOLUTION IN SUPERSONIC
FLOW. Dorris M. Ehret. August 1952. 26p.
diagrs. (NACA TN 2764)

The accuracy and range of applicability of the line-
arized theory, second-order theory, tangent-cone
method, conical-shock-expansion theory, and New-
tonian theory for predicting pressure distributions on
pointed bodies of revolution at zero angle of attack
are investigated. Various body shapes are included
in the investigation and a wide range of supersonic
Mach numbers and fineness ratios is included. It
is found that, for most combinations of Mach number
and fineness ratio, one of the approximate methods
will give pressure drag within 10 percent.


NACA TN 2767

DYNAMICS OF MECHANICAL FEEDBACK-TYPE
HYDRAULIC SERVOMOTORS UNDER INERTIA
LOADS. Harold Gold, Edward W. Otto and Victor L.
Ransom. August 1952. 63p. diagrs., photos.
(NACA TN 2767)

An analysis of the dynamics of mechanical feedback-
type hydraulic servomotors under inertia loads is de-
veloped and experimental verification is presented.






4


This analysis, which is developed in terms of two
physical parameters, yields direct expressions for
the following dynamic responses: (1) the transient
response to a step input and the maximum cylinder
pressure during the transient and (2) the variation of
amplitude attenuation and phase shift with the fre-
quency of a sinusoidally varying input. Close agree-
ment was obtained between analytically determined
responses and measured responses.



NACA TN 2768

SUPERSONIC FLOW WITH WHIRL AND VORTICITY
IN AXISYMMETRIC CHANNELS. Ralph J. Eschborn.
August 1952. 41p. diagrs. (NACA TN 2768)

Axially symmetric supersonic steady flow with vorti-
city and rotation about the axis is treated by the meth-
od of characteristics. Several cases are calculated
for flow in annular channels.



NACA RM E52F05

ANALYSIS OF FULLY DEVELOPED TURBULENT
HEAT TRANSFER AT LOW PECLET NUMBERS IN
SMOOTH TUBES WITH APPLICATION TO LIQUID
METALS. Robert G. Deissler. August 1952. 20p.
diagrs. (NACA RM E52F05)

An analysis was made of heat transfer at low Peclet
numbers for fluids flowing turbulently in smooth
tubes. Previous analyses for flow of gases and
liquid metals at low Peclet numbers gave higher heat-
transfer coefficients than were indicated experi-
mentally. When the mixing-length theory was modi-
fied in order to account for the heat transferred by
conduction to a turbulent particle as it moves trans-
versely, the predicted results were brought into
agreement with the experimental results.


NACA RM E52F27

MINIMUM IGNITION ENERGIES OF SIX PURE
HYDROCARBON FUELS OF THE C2 AND C6 SERIES.
Allen J. Metzler. August 1952. 22p. diagrs., 3 tabs.
(NACA RM E52F27)

Minimum spark-ignition energies at reduced pres-
sures are reported for ethane, ethylene, acetylene,
n-hexane, cyclohexane, and benzene; and the mean
energy-pressure dependence is established to be
1.76
E 1/P Minimum ignition energies E at 1
atmosphere predicted by this relation for these fuels
correlate with the maximum fundamental flame
velocity Umax and may be expressed approximately
as Umax l/E0"'8. Such interdependence of the min-
imum ignition energy and maximum fundamental
flame velocity permits a reasonable estimation of
either from the other with an accuracy sufficient to
discern large differences in various pure fuels.


NACA
RESEARCH ABSTRACTS NO.28



BRITISH REPORTS


N-16746*

Royal Aircraft Establishment (Gt. Brit.)
THE FATIGUE SITUATION FOR CIVIL AIRCRAFT.
P. B. Walker. May 1952. 4p. (RAE Structures
129)

This report is a reproduction for official use of a
paper published in "The Aeroplane" for 25th April,
1952. The fatigue situation is reviewed briefly by
eliminating all issues that appear to be secondary.
There are found to be two main objectives: (a) to
prevent fatigue accidents and (b) to obtain a long fa-
tigue life. These are related to the broad technical
picture which is also reviewed briefly. The con-
clusion reached is that the second objective is the
more difficult to achieve.


N-16747*

Royal Aircraft Establishment (Gt. Brit.)
FLASH WELDING OF HIGH TENSILE STEEL TUBES
- TEMPERATURE MEASUREMENTS. H. Brooks.
December 1951. 28p. diagrs., photo., 6 tabs.
(RAE Tech. Note Met. 153)

Measurements have been made to determine the ef-
fects of process variables on the temperatures pro-
duced in high tensile alloy steel tubes by the flashing
phase of the welding cycle. The most important ef-
fects are those of flashing distance and speed. Ini-
tially, increases of flashing distance cause large
temperature rises, but the effect diminishes as
steady thermal conditions are approached. The
steepness of the steady-state thermal gradients de-
pends on the flashing speed, high speeds giving steep
gradients. The effect is also apparent for nonsteady
conditions if the gradients produced by different
flashing speeds are compared on the basis of equal
flashing distances. Average interface temperatures
approximating to the steel melting point can only be
attained at flashing speeds of about 1. 0 in/min and
higher. Machine secondary voltage was found to
have a small inverted effect, higher temperatures
being obtained with low voltages than with high.
Within the range investigated, the effect of final die
opening was'negligible. Each particular set of
flashing conditions produces very similar tempera-
tures in tubes of different compositions and sizes.


N-16748*

Aeroplane and Armament Experimental Establishment
(Gt. Brit.) THE LOW SPEED PERFORMANCE OF A
HELICOPTER. A. L. Oliver. May 15, 1952. 12p.
diagrs. (AAEE Rept. A. A. E. E. /Res/264)

The analysis and estimation of helicopter perform-
ance is dependent upon the accurate assessment of
rotor induced velocity. An empirical curve relating
the flow through the rotor to the flight speed is used
for vertical flight and the momentum theory is suffi-
ciently accurate for a tip speed ratio greater than






NACA
RESEARCH ABSTRACTS NO.28


about 0.1, but no simple method has been generally
available for the intermediary speed range. Sets of
empirical curves covering this speed range and based
on the analysis of low speed flight performance are
given in this report. The charts give values of the
rotor induced velocity varying smoothly from the ver-
ical flight state to the forward flight region in which
the momentum theory becomes accurate. The charts
are presented in forms suitable for determining
steady flight performance and also for estimating ro-
tor thrust during accelerated motion in, for example,
take-off flight.


N-16754*

Royal Aircraft Establishment (Gt. Brit.)
A DEAD WEIGHT CALIBRATOR CAPABLE OF
MEASURING PRESSURES GREATER OR LESS THAN
ATMOSPHERIC FROM A VARIABLE DATUM PRES-
SURE. K. R. Honick and F. Solari. February
1952. 9p. diagrs., photo. (RAE Tech. Note
AP 1010)

A dead weight calibrator is described which is capa-
ble of measuring pressures both greater and less
than atmospheric above or below a variable datum
pressure. Possible applications to the service test-
ing of airspeed indicators, Mach meters, and altim-
eters are discussed.


N-16760*

Royal Aircraft Establishment (Gt. Brit.)
THE DETERMINATION OF SKIN TEMPERATURES
ATTAINED IN HIGH SPEED FLIGHT. F. V. Davies
and R. ". Monaghan. February 1952. 65p. diagrs.,
7 tabs. (RAE Aero 2454)

This report discusses the factors affecting skin tem-
peratures attained by high-speed missiles and pre-
sents some methods of solution. These have been
reduced to graphical or tabular form and are set out
in order of complexity. Graphical or algebraic solu-
tions may be quickly obtained if steady conditions are
assumed, and for some flight cases these are reason-
able approximations to corresponding transient solu-
tions. If the temperature time variation is required,
then longer numerical integration processes have to
be performed. Account may be taken of external
radiation and heat loss to the interior if their effects
are considered significant. Although the emphasis of
this report is on the calculation of average tempera-
tures attained by thin skins, a method of calculating
the temperature-space-time variation through three-
dimensional bodies has been included assuming steady
conditions at the surface. Numerical examples are
included for each section of the report.



N-16787*

Aeronautical Research Council (Gt. Brit.)
EXPERIMENTS ON DISTRIBUTED SUCTION
THROUGH A ROUGH POROUS SURFACE.
Cambridge University Aeronautical Laboratory.
1952. 7p. diagrs. (ARC CP 84)


Flight tests in which suction was applied through a
slightly rough porous surface to maintain laminar
flow in the boundary layer have shown that when the
pressure on the surface was uniform there was an
upper limit to the airspeed outside the layer above
which no reasonable suction would prevent transition
to turbulence. Comparison between these and similar
tests on a smoother surface suggest that there will
be, associated with every porous surface, two limit-
ing speeds, one above which no reasonable suction
will maintain laminar flow and one below which the
surface can be regarded as aerodynamically smooth.
Consideration is given to the way in which these
speeds will vary with the kinematic viscosity of the
air, in conditions which lead to dynamical similarity.



N-16788*

Aeronautical Research Council (Gt. Brit.)
A BRIEF SURVEY OF SOME METHODS AND INFOR-
MATION CONCERNING THE AERODYNAMIC DE-
RIVATIVES OF WINGS IN UNSTEADY MOTION AT
TRANSONIC AND SUPERSONIC SPEEDS. W. E. A.
Acum. 1952. 17p. diagrs., tab. (ARC CP 85)

Reviews, briefly, present theories concerning the
problem of the oscillating wing in supersonic flow and
the methods by which it is handled. Includes discus-
sions of two- and three-dimensional wings and of
wings of various plan forms. It discusses not only
simple-harmonic or continuous motions but discusses
sudden motions as when a sharp edged gust is en-
countered. There is a bibliography.


N-16789*

Aeronautical Research Council (Gt. Brit.)
PRESSURE AND BOUNDARY LAYER MEASURE-
MENTS ON A 59 SWEPTBACK WING AT LOW
SPEED AND COMPARISON WITH HIGH SPEED RE-
SULTS ON A 45 SWEPT WING. PARTS I & 11H.
Tunnel Staff of Aero Department & G. G. Brebner.
1952. 62p. diagrs., 19 tabs. (ARC CP 86)

The low speed pressure distributions has been meas-
ured over a range of incidence on a 59 swept wing of
symmetrical section t/c 14 percent, aspect ratio 3. 61,
and taper ratio 4 to 1. These results have been com-
pared, using the linear perturbation theory, with
those on a 45 swept wing aspect ratio 5. 87 at
M = 0. 8. There is fairly good agreement at zero
incidence but lift distribution does not appear to be
predicted so well. The results on the 59 wing show
clearly the large effects of sweepback on both the
pressure distribution at zero incidence and the lift
distribution near the center section of the wing.
Comparisons with theoretical estimates at zero inci-
dence show good agreement.


N-16790*

Aeronautical Research Council (Gt. Brit.)
STRUCTURAL ASPECTS OF SULCTION WINGS. E.
H. Mansfield. 1952. 24p. diagrs. (ARC CP 87)






6


This report considers the structural design problems
arising directly from the use of distributed wing suc-
tion. Possible types of construction are discussed
and estimates are made of the increase in aircraft
all up weight due to these constructions and due to the
extra power required for suction.


N-16791"

Aeronautical Research Council (Gt. Brit.)
FATIGUE TESTS ON TYPICAL TWO SPAR LIGHT
ALLOY STUL(C TIRES (METEOR 4 TAILPLANES)
UNDER REVERFSED LOADING K. D. Raithby.
1952. 24p. diagrs. photos., 3 tabs. (ARC CP 88)

Results are given for fatigue tests on six Meteor 4
tail planes vibrated in flexure under simple reversed
loading, r.,'.,inii from _10 percent to t30 percent of
the static f.tilijL load. Corresponding endurances
varied from about 5 x 10 to 0.06 x 106 cycles, for
complete failure of a spar boom. In each test, the
allerirjtiii load was kept constant, although progres-
sive skin c ,ji 1:iiiir caused a considerable change in
alternating stress at the section where eventual fail-
ure of the spar boom occurred. The test results are
discussed in relation to the establishment of endur-
ance curves for a typical two-spar structure.


N-lt.792"

Aeronautical Research Council (Gt. Brit.)
NOTES AND GRAPHS FOR BOUNDARY LAYER CAL-
CULATIONS IN COMPRESSIBLE FLOW. W. F.
Cope. 1952. 22p. diagrs. (ARC CP 89)

Formulas are given for calculating the skin-friction
coefficients and the various parameters associated
with the boundary layer up to Mach numbers of 4.
The calculations have been made for a laminar bound-
ary layer with a sinusoidal velocity distribution; for
a turbulent boundary layer with a "power law" veloc-
ity distribution, the distribution following "one-fifth, "
"one-seventh, "one-ninth, and "one-eleventh" pow-
er laws; and for a turbulent boundary layer with a
"log law" velocity distribution.


N-16842*

Royal Aircraft Establishment (Gt. Brit.)
CORROSION AND FATIGUE TESTS ON MAGNESIUM
ALLOYS TREATED BY A FRENCH GALVANIC PRO-
CESS. H. G. Cole. February 1952. 13p. diagrs.,
4 tabs. (RAE Tech.Note Met.156)

The Frasch galvanic process carried out in a solu-
tion of zinc dichromate containing a small amount of
free chromic acid (Example I of B.P. Application
22986/46) gave good protection to three types of mag-
nesium alloy and provided an excellent base for paint.
Neither the Frasch galvanic process nor the RAE
electrolytic chromate treatment caused any signifi-
cant reduction of fatigue strength of magnesium alloy
extruded bar to D.T.D.259. Chromate treatment in
the RAE hot half hour bath caused an increase in fa-
tigue strength.


NACA
RESEARCH ABSTRACTS NO.28


N-16843*

Royal Aircraft Establishment (Gt. Brit.)
MEASUREMENT OF MAXIMUM LIFT COEFFICIENT
OF AN AIRCRAFT WITH FLAPS AND LEADING
EDGE SLATS (PRESTWICK PIONEER VL.516).
R. Maine. January 1952. 14p. diagrs., 3 tabs.
(RAE Tech.Note Aero 2143)

This note describes flight measurements of maximum
lift coefficients with various combinations of flaps
and slats. The maximum lift coefficient with flaps
fully down and slats open was originally only 2.41 but
this was increased to 2.71 by sealing some handholds
in the wing leading edge. The measured increments
in maximum lift coefficient due to the flaps and slats
are compared with estimated values.



MISCELLANEOUS


NACA Rept. 1055

Errata No. 1 on "COMPARISON OF THEORETICAL
AND EXPERIMENTAL HEAT TRANSFER CHARAC-
TERISTICS OF BODIES OF REVOLUTION AT
SUPERSONIC SPEEDS". Richard Scherrer. 1951.



UNPUBLISHED PAPERS


N-9717*

Calif. Inst. of Tech. Guggenheim Aeronautical Lab.
INVESTIGATION OF DIRECT AND ALTERNATING
CURRENT GLOW ANEMOMETERS. A. J. A.
Morgan and T. Vrebalovich. August 1950. ii, 49p.
diagrs., photos. (Calif. Inst. of Tech. Guggenheim
Aeronautical Lab.)

The glow anemometer is particularly suited for the
measurement of turbulence in applications for which
the hot-wire is unsuitable as in supersonic flow. The
experimental work, so far, has been directed towards
the perfection of a workable instrument with the de-
sired characteristics. A resume of this work is
given in the present report and divides itself naturally
into direct-, intermittent-, and alternating-glow
studies.


N-12000*

Johns Hopkins U.
ASYMPTOTIC EXPANSION OF THE WHITTAKER'S
FUNCTION Wk m(Z) FOR LARGE VALUES OF k, m,
z. Chieh-Chien Chang, Boa-Teh Chu and Vivian
O'Brien. September 1951. i, 54p. diagrs. (Johns
Hopkins U.)

This problem of behavior, although mathematical in
nature, arises in approximating to the third order the
hodograph solution of transonic flow as shown in a
previous report of the senior author. Debye's meth-
od of steepest descent has been applied, with Langer's
method used as a check and comparison. Subsonic,
sonic and supersonic flows have been investigated.





NACA
RESEARCH ABSTRACTS NO.28 7


Some numerical examples of the asymptotic solutions
have been caluclated for comparison with exact values.
The subsonic and sonic cases seem to check reason-
ably well even for fairly small eigenvalues; the
supersonic case does not check nearly so well for
moderate n.


N-12131*

ON THE ADDITIONAL LIFT CAUSED BY A COM-
PRESSION SHOCK. (Uber den durch einen Verdich-
tungsstoss verursachten Zusatzauftrieb). H. B.
Helmbold. February 1952. 17p. diagrs. (Trans.
from Ingenieur-Archiv, v. 17, 1949, pp. 280-287).

The additional lift of the compression may be calcu-
lated by interpreting the shock as a compression sink
with which a system of spatially distributed expansion
sources of opposite-equal total strength is connected.
The lift-reducing influence of the expansion sources
may be determined in the first approximation accord-
ing to the streamline analogy.


N-12764*

ON THE PROBLEM OF ROLLING-IMPACT STRESS
OF AIRPLANE LANDING GEARS. (Zur Frage der
Rollstossbeanspruchung von Flugzeugfahrwerken).
K. Schlaefke. May 1952. 25p. diagrs. (Trans.
from Aerodynamische Versuchsanstalt Gottingen E.
V., Technische Berichte, v. 11, no. 9, 1944, pp. 289-
296).

In connection with a previous article on landing im-
pact, this article deals with the behavior of airplane
landing gears while rolling over ground obstacles.
After a brief survey of past reports, the differential
equation of the oscillation process is set up and gen-
erally solved. Subsequently, the numerical calcula-
tion is carried out far enough so that a number of
questions about appropriate improvement of landing
gears can be answered.



N-12823*

Washington U., Seattle. Aeronautical Lab.
AN APPROACH TO THE PROBLEM OF DEVELOP-
ING FUNCTIONS SATISFYING BOUNDARY CON-
DITIONS OF PLATE THEORY. Harold C. Martin.
1951. 19p. diagrs. (Washington U., Seattle. Aero-
nautical Lab.)

An approach is made to the problem of selecting func-
tions satisfying certain boundary conditions appearing
in the theory of thin elastic plates. The problems
used for illustrating the suggested method are: (1)
stress function for the middle plane stresses of the
clamped rectangular plate (large deflections), and (2)
deflection function for the uniform cantilever plate
(small deflections).


NACA-Langley 9-10-52 -4000




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