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:
AA00009235:00093

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National Advisory Committee for Aeronautics


Research Abstracts


N0.36


JANUARY 16, 1953


CURRENT NACA REPORTS


NACA Rept. 1082


METHOD OF ANALYSIS FOR COMPRESSIBLE FLOW
THROUGH MIXED-FLOW CENTRIFUGAL IMPFL-
LERS OF ARBITRARY DESIGN. Joseph T. Han, r ok,
Ambrose Ginsburg and Walter M. Osborn. 1952.
ii, lOp. diagrs. (NACA Rept. 1082. Formerly \
NACA TN 2165)

A method is presented for the analysis of compress-
ible flow between the hub and the shroud of mixed-
flow impellers of arbitrary design. Axial symmetry
was assumed, but the forces in the meridional (hub-
shroud) plane, which are derived from tangential
pressure gradients, were taken into account. The
method was applied to an experimental mixed-flow
impeller. The analysis of the flow in the meridional
plane of the impeller showed that the rotational
forces, the blade curvature, and the hub-shroud pro-
file can introduce severe velocity gradients along the
hub and shroud Surfaces. Choked flow at the impel-
ler inlet as determined by the analysis was verified
by experimental results.


NACA TN 2845

X-RAY INSTRUMENTATION FOR DENSITY MEAS-
UREMENTS IN A SUPERSONIC FLOW FIELD.
John Dimeff, Ralph K. Hallett, Jr. and C. Frederick
Hansen. December 1952. 39p. diagrs., photos.,
2 tabs. (NACA TN 2845)

An instrument has been constructed to measure the
density of an air stream by utilizing the reduction in
intensity of an undeviated beam of X rays. This
equipment has been designed for density ranges from
2 x 10-5 to 3 x 10-4 grams per cubic centimeter.
Path-length-density products were measured within
5 x 10-5 g/cm2 for X-ray-beam areas of 5 x 10-4
cm2 and averaging times of 30 seconds, and within
1 x 10- g/cm- for beam areas of 8 x 10-3 cm2 and
averaging times of 5 minutes.


NACA TN 2850

STUDY OF PRESSURE EFFECTS ON VAPORIZA-
TION RATE OF DROPS IN GAS STREAMS. Robert
D. Ingebo. January 1953. 36p. diagrs., 5 tabs.
(NACA TN 2850)

Vaporization-rate and surface-temperature data were
obtained for four pure liquids evaporating from the
surface of a porous sphere in air streams having a
I


*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.


NO-36


I


static pressure range of 450 to 1500 millimeters of
*mercury. Data were also obtained for methanol
evaporating in streams of helium, argon, and carbon
dioxidAe Experimental heat-transfer coefficients
were 1ound to correlate a semiempirical equation
which sbows the Nusselt number to be a function of
the group ReSc, the thermal-conductivity ratio, and
the mol9cular-scale momentum-transfer ratio of
gra. itational to inertial forces. These data show the
heat-transfer coefficient to be independent of the
static pressure of the gas stream, and the effect of
pressure ,'n the vaporization rate to be determined
dfrectlv by the effect of pressure on the surface
temperature of the drop. An equation is also pre-
sented for calculating the driving potential At value
for water at a static pressure of 450 to 1500 milli-
meters of mercury by using the At* value for 1 at-
mosphere pressure and a calculated correction term
At'.


NACA TN 2853

A STUDY OF THE APPLICATION OF POWER-
SPECTRAL METHODS OF GENERALIZED HARMON-
IC ANALYSIS TO GUST LOADS ON AIRPLANES.
Harry Press and Bernard Mazelsky. January 1953.
48p. diagrs., 2 tabs. (NACA TN 2853)

The applicability of some results from the theory of
generalized harmonic analysis to the analysis of gust
loads on airplanes in continuous rough air is exam-
ined. The input and output relations in terms of
power spectrums are used to relate the standard de-
viation (root mean square) of loads in continuous
rough air to the gust response characteristics of the
airplane and the spectral characteristics of atmos-
pheric turbulence. For the case of a normally dis-
tributed output, which appears from experimental
evidence to apply to a homogeneous turbulence condi-
tion, the probability distribution of loads is shown to
be a simple function of the output power spectrum.
In order to illustrate the application of power-
spectral analysis to gust loads and to obtain an in-
sight into the relation between loads in continuous
rough air and the gust response characteristics of the
airplane, two selected series of calculations are pre-
sented. The results of these applications are com-
pared with those obtained from calculations for single
gusts and their implications are discussed.

NACA TN 2854

AVERAGE SKIN-FRICTION DRAG COEFFICIENTS
FROM TANK TESTS OF A PARABOLIC BODY OF
REVOLUTION (NACA RM-10). Elmo J. Mottard and
J. Dan Loposer. January 1953. 18p. diagrs.,
photos. (NACA TN 2854)







2


Average skin-friction drag coefficients were obtained
from boundary-layer total-pressure measurements on
a parabolic body of revolution (NACA RM-10) basic
fineness ratio 15) in water at Reynolds numbers from
4. 4 x 106 to 70 x 106. The tests were made in the
Langley tank no. 1 with the body sting-mounted at a
depth of two maximum body diameters. The arith-
metic mean of three drag measurements taken around
the body was in good agreement with flat-plate re-
sults, but, apparently because of the slight surface
wave caused by the body, the distribution of the
boundary layer around the body was not uniform over
part of the Reynolds number range.


NACA TN 2861

ANALYTICAL INVESTIGATION OF ICING LIMIT
FOR DIAMOND-SHAPED AIRFOIL IN TRANSONIC
AND SUPERSONIC FLOW. Edmund E. Callaghan
and John S. Serafini. January 1953. 18p. diagrs.
(NACA TN 2861)

Calculations have been made for the icing limit of a
diamond airfoil at zero angle of attack in terms of
the stream Mach number, stream temperature, and
pressure altitude. The icing limit is defined as a
wetted-surface temperature of 32 F and is related
to the stream conditions by the method of Hardy.
The results show that the point most likely to ice on
the airfoil lies immediately behind the shoulder and
is subject to possible icing at Mach numbers as high
as 1. 4.


NACA TN 2866

ICING PROTECTION FOR A TURBOJET TRANS-
PORT AIRPLANE: HEATING REQUIREMENTS,
METHODS OF PROTECTION, AND PERFORMANCE
PENALTIES. Thomas F. Gelder, James P. Lewis
and Stanley L. Koutz. January 1953. i, 57p.
diagrs., tab. (NACA TN 2866)

The heating requirements for several methods of
icing protection for a typical turbojet transport air-
plane operating over a probable range of icing condi-
tions are evaluated, and the airplane performance
penalties associated with providing this protection
from various energy sources are assessed. Con-
tinuous heating requirements and airplane penalties
for the turbojet transport are considerably increased
over those for lower-speed aircraft. Heating re-
quirements can be substantially reduced by use of a
cyclic de-icing system and choice of the proper
energy source.


NACA RM E52J13

PREDICTION OF FLAME VELOCITIES OF HYDRO-
CARBON FLAMES. Gordon L. Dugger and Dorothy
M. Simon. January 1953. 23p. diagrs., 3 tabs.
(NACA RM E52J13)

The effects of four combustible-mixture variables on
the laminar flame velocities of hydrocarbon-oxygen-
nitrogen mixtures are predicted by semitheoretical


NACA
RESEARCH ABSTRACTS N0.36


methods based on (1) Semenov equation (thermal
mechanism), (2) Tanford-Pease equation (active-
particle-diffusiQn mechanism), and (3) Manson equa-
tion (momentum-pressure-drop equation using active-
particle concentrations). A semiempirical factor,
calculated from flame velocity data, is required by
each of these equations. When these factors are
calculated for each variable separately, mean devia-
tions between calculated and measured flame veloci-
ties are 2 to 15 percent for the variables studied,
namely, hydrocarbon structure, equivalence ratio,
oxygen-nitrogen ratio, and initial temperature.
When the semiempirical factor for one variable is
used to predict the effect of another variable, the
mean deviations are approximately doubled.
Empirical equations are summarized which give
better predictions, but require more constants.


NACA RM E52J24

FLAME VELOCITIES OF PROPANE- AND
ETHYLENE-OXYGEN-NITROGEN MIXTURES.
Gordon L. Dugger and Dorothy D. Graab. January
1953. 23p. diagrs., 3 tabs. (NACA RM E52J24)

Laminar flame velocities of propane and ethylene
with oxygen-nitrogen mixtures containing 0. 166 to
0. 496 mole fraction of oxygen were determined as a
function of mixture composition at 311 and 4220 K
by a Bunsen-burner method. For each case flame
velocity increased linearly with oxygen concentration.
Empirical equations including the effects of initial
temperature and oxygen concentration were obtained.
Thermal and diffusion theories were used to predict
the relative effect of oxygen concentration on maxi-
mum flame velocity within 5 to 15 percent. No line-
ar correlations between maximum flame velocity and
calculated active particle concentrations were ob-
tained.


NACA RM E52J28

SPARK IGNITION OF FLOWING GASES. III EF-
FECT OF TURBULENCE PROMOTER ON ENERGY
REQUIRED TO IGNITE A PROPANE-AIR MIXTURE.
Clyde C. Swett, Jr. and Richard H. Donlon.
January 1953. 7p. diagrs. (NACA RM E52J28)

An investigation was conducted to determine the ef-
fect of turbulence generated by different sizes of
wire grid on the minimum spark-ignition energy of a
flowing propane-air mixture. Test conditions were:
pressure, 5 inches of mercury absolute; tempera-
ture, 80 F; fuel-air ratio, 0. 0835 (by weight);
velocity, 50 to 250 feet per second; spark duration,
500 microseconds; and electrode spacing, 0. 37 inch.
The wire sizes of the turbulence promoters ranged
from 0. 006 to 0. 105 inch in diameter and the pro-
moters were located either 4-3/8 or 6-3/8 inches
upstream of the spark electrodes. The investigation
was conducted with turbulence having superimposed
flow pulsations and duct resonance. The required
ignition energy increased with wire size of the turbu-
lence promoter and with gas velocity and decreased
with distance from the promoter to the spark elec-
trodes. The required ignition energy therefore in-







NACA
RESEARCH ABSTRACTS NO.36


creased with those factors that are reported to
generate increased intensity of turbulence. At a
velocity of 250 feet per second, three times more
energy was required with the 0. 105-inch wire-
diameter promoter than with no promoter.


NACA TM 1324

STEADY VIBRATIONS OF-WING OF CIRCULAR
PLAN FORM. (Ob ustanovivshikhsya kolebaniyakh
kryla krugovoi formy v plane). THEORY OF WING
OF CIRCULAR PLAN FORM. (Teoriya kryla
konechnogo razmakha krugovoi formy v plane).
N. E. Kochin. January 1953. 93p. diagrs.
(NACA TM 1324. Trans. from: Prikladnaya
Matematika i Mekhanika, v. 6, no. 4, 1942, p. 287-
316; Prikladnaya Matematika i Mekhanika, v. 4, no. 1,
1940, p. 3-32).

This paper treats the problem of determining the lift,
moment, and induced drag of a thin wing of circular
plan form in uniform incompressible flow on the basis
of linearized theory. As contrasted to a similar
paper by Kinner, in which the acceleration potential
method was used, the present paper utilizes the con-
cept of the velocity potential. Calculations of the
lift and moment are presented for several deformed
shapes. It is shown that considerable deviations
exist between the strip theory analysis and the more
exact theory. The lift, moment, and induced drag
are also determined for a harmonically oscillatory
circular plan form wing. As constrastedto a similar
paper by Schade, in which the acceleration potential
method was used, the present paper utilizes the con-
cept of the velocity potential. Expressions for lift,
moment, and induced drag are given and finally
specialized to the case of a slowly oscillating circu-
lar wing.



BRITISH


N-17876*

National Gas Turbine Establishment (Gt. Brit.)
A DIRECT, EASILY COMPUTABLE METHOD FOR
THE EVALUATION OF CENTRIFUGAL AND
THERMAL STRESSES IN DISCS, AND STRESS
CHANGES DUE TO PLASTIC FLOW AND CREEP.
R. L. Brooking, J. Brown and B. R. Atkins. July
1952. 68p. diagrs., 7 tabs. (NGTE R. 122)

A method is presented below by the use of which
stressing of turbine disks may be performed. It per-
mits the evaluation of stresses due both to rotation,
and to existence of a thermal gradient radially
across the disk. The method is extended to cover
the calculation of the stress changes which occur at
any point under conditions where stresses exceed the
elastic limit of the disk material (plastic flow), or
where the disk is rotating for long periods of time
under given conditions (creep). The method is a
direct one in that it involves neither initial stress
assumptions nor successive approximations. It may
be described as a small-difference, step-by-step
method, and can be set out in an easily computable


3


form, the operation of which requires little mathe-
matical knowledge. Two examples of the application
of the method are given. One treats an aeroengine
turbine disk in which the stress changes due to
plastic flow are included, and the results obtained by
this are compared with those obtained using a some-
what more mathematical method due to Prof. Hartree.
Good agreement is exhibited. The second example
shows the evaluation of the stress distribution in a
rotor after 10,000 hours under steady running condi-
tions, the latter example showing also the application
to this problem of a current theory on creep data.


N-20200*

National Gas Turbine Establishment (Gt. Brit.)
THE RELATIONSHIP BETWEEN THE CREEP AND
TENSILE PROPERTIES AT ELEVATED TEMPER-
ATURE OF NIMONIC 80. A. Graham and K. F. A.
Walles. August 1952. 45p. diagrs., 9 tabs.
(NGTE R. 100)

A variety of empirical formulas is available to rep-
resent the effect of stress, time, rate, and temper-
ature, on deformation, and the report describes the
experimental side of an attempt to combine the more
promising of them into a comprehensive theory
which may be usefully applied to a commercial ma-
terial.


N-20231*

Forest Products Research Lab. (Gt. Brit.)
INVESTIGATIONS INTO GLUES AND GLUING.
PROGRESS REPORT SIXTY-NINE AUGUST 1952.
THE COMPARATIVE DURABILITY OF PLYWOOD
GLUES IN ENGLAND AND IN NIGERIA (SERIES IV).
SECOND YEAR'S ANALYSIS. J. F. S. Carruthers,
P. Burgess and A. M. Thomas. (Superseding Pro-
gress Rept. 62, May, 1951). llp. 2 tabs. (Forest
Products Research Lab.)

Since 1940 this Laboratory has been conducting tests
on the durability of plywood adhesives in various
environments in the United Kingdom. This report is
concerned with an extension of these experiments to
include exposures in the tropics.


N-20232*

Forest Products Research Lab. (Gt. Brit.)
INVESTIGATIONS INTO GLUES AND GLUING.
PROGRESS REPORT SIXTY-FOUR JANUARY,
1952. THE DURABILITY OF ASSEMBLY GLUES -
SERIES A. FIFTH-YEAR REPORT ON THE PLY-
CLAD FRAME TESTS. R. A. G. Knight, L. S.
Doman and G. E. Soane. 14p. photos., 6 tabs.
(Forest Products Research Lab.)

This report records the observations made of the
durability of assembly glues tested by a ply-clad
frame unit, one side of which has been fully exposed
to weather and the other protected by a hutch through
which unheated outside air can circulate.





3 1262 09079 7597 III I
312200979


4


N-20233*

Forest Products Research Lab. (Gt. Brit.)
INVESTIGATIONS INTO GLUES AND GLUING.
PROGRESS REPORT SIXTY-SEVEN SEPTEMBER,
1952. DURABILITY OF ASSEMBLY GLUES -
SERIES B. FIFTH-YEAR REPORT ON LAMINATED
BEAMS. R. J. Newall and J. E. Grosert. (Super-
seding Progress Rept. 54, May, 1950). 9p. diagrs.
(Forest Products Research Lab.)

This report describes one of the series of inEstiij-
tions bein1. made by the Laboratory of the durability
of adhesives in various kinds of joints under different
exposure conditions. The test units in this case are
laminated beams of different widths made with
assembly glues representative of the main types,
namely animal, casein, urea- and phenol-
fi mnaldehydt resins.


N-20257*

Aeronautical Research Council (Gt. Brit.)
OBSERVATIONS ON A THIN CAMBERED AEROFOIL
BEYOND THE CRITICAL MACH NUMBER. E. W.
E. Rogers. July 7, 1950. 23p. diagrs., photos.
(ARC 13, 238; Perf. 685; FM 1455)

In the course of surface pressure measurements and
wake traverses on an airfoil section of 10-percent
thickness-chord ratio, tested at high subsonic speeds
in the 20 in. x 8 in. (50. 8 cm, x 20. 3 cm) high speed
tunnel of the National Physical Laboratory, it was
discovered that at a particular incidence (3. 7) an
extensive region of supersonic velocity (M = 1.15)
existed without the formation of a well-defined shock
wave or a rise of drag. The drag coefficient in fact
decreased markedly as the Mach number was raised
from a low value, and this was accompanied by a
rearward movement on the upper surface of the posi-
tion of boundary layer transition corresponding to a
favorable change of the surface pressure gradient.
In an attempt to explain this phenomenon, some
analysis is made of the observed pressure distribu-
tion curves, and the measured transition positions
are compared with those estimated from the ob-
served drag coefficients. Direct shadow photographs
illustrate the development of the shockwave pattern.


N-20260+

Aeronautical Research Council (Gt. Brit.)
A NOTE ON THE BOUNDARY LAYER AND STALL-
ING CHARACTERISTICS OF AEROFOILS.
D. D. Carrow. October 5, 1950. 21p. diagrs.
(ARC 13, 424; Perf. 697; S & C 2435)

A qualitative explanation is suggested for the changes
which occur in the stalling characteristics of airfoils
as the Reynolds number is increased. This explana-
tion is based on the variation, with Reynolds number,
in the state of the boundary layer along the upper
surface at just below the stalling incidence.


MISCELLANEOUS


NACA Rept. 1041

Errata No. 1 on "EQUATIONS AND CHARTS FOR
THE RAPID ESTIMATION OF HINGE-MOMENT AND
EFFECTIVENESS PARAMETERS FOR TRAILING-
EDGE CONTROLS HAVING LEADING AND TRAIL-
ING EDGES SWEPT AHEAD OF THE MACH LINES".
Kennith L. Goin. 1951.




UNPUBLISHED PAPERS


12887 *

TURBULENT HETEROGENEOUS COMBUSTION.
i(Turbulentnoe geterogennoe gorenie). S. A.
Goldenberg. 16p. diagrs. (Trans. from Izvestia
Akademii Nauk SSSR, no. 8, August 1950, p. 1154-
1164).

An experimental investigation was made of the pro-
cess of combustion of carbon in the form of a cylind-
rical tube for turbulent flow of the gases with veloci-
ties from 22 to 145 meters per second. On the basis
of the hydrodynamic characteristics determining the
transport of the masses in the turbulent flow (the
coefficient of turbulent diffusion), an approximate
analytical method is given for the computation of the
combustion process. The temperature dependence
was obtained for the coefficient of gas exchange with-
in the temperature range 500 to 1050, which is ex-
pressed by the formula a z 8.5 x 105 exp
(-18, 000/RT).


NACA-Langley 1-16-53 4000




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