Research abstracts

National Advisory Committee for Aeronautics \



Research, tractss
NO.79 MARCH 11, 1955


CURRENT NACA REPO

NACA Rept. 1156 z1

EXPERIMENTS TO DETERMINE NEIGHBORHOOD D
REACTIONS TO LIGHT AIRPLANES WITH AND
WITHOUT EXTERNAL NOISE REDUCTION. Fre
Elwell, Aeronautical Research Foundation. 1953.
ii, 43p. diagrs., photos., 12 tabs. (NACA Rept. 1156.
-Formerly TN 2728)

Experiments to determine neighborhood reactions to
the noise of light airplanes with and without noise-
reduction equipment were conducted at a number of
sites which might be convenient locations for landing
strips within the metropolitan area of Boston, Mass.
TWO standard airplanes and two airplanes modifiedby
reduction gears, four-bladed propellers, and engine
exhaust silencers were used. Flights were made
.lose to residential properties of varying income
S:levels, population densities, and proximity to trade
tii':enters in order to determine whether the degree of
: noise reduction previously found to be aerodynami-
ally and structurally practicable produced a signifi-
cant reduction in neighborhood objections to such air-
craft operations.


NACA Rept. 1157

ANALYTICAL DERIVATION AND EXPERIMENTAL
EVALUATION OF SHORT-BEARING APPROXIMA-
TION FOR FULL JOURNAL BEARINGS. George B.
DuBois and Fred W. Ocvirk, Cornell Uruv. 1953.
ii, 32p. diagrs., photos., 4 tabs. (NACA Rept. 1157.
Formerly TN 2808; TN 2809)

S An approximate analytical solution including the ef-
feet of end leakage from the oil film of short plain
bearings is presented because of the importance of
endwise flow in sleeve bearings of the short lengths
commonly used. The analytical approximation is
supported by experimental data and includes the end-
.Z..d i .ug1,w and that part of the circumferential flow
Which is related to surface velocity and film thick-
ness. Methods are also discussed for approximating
a maximum bearing temperature for pressure-
lubricated bearings and for evaluating the effect of
deflection in misalinement on the eccentricity ratio
at the ends of a bearing.


NACA Rept. 1166

RELATION BETWEEN ROUGHNESS OF INTERFACE
AND ADHERENCE OF PORCELAIN ENAMEL TO
STEEL. J. C. Richmond, D. G. Moore, H. B.
Kirkpatrick and W. N. Harrison, National Bureau of
Standards. 1954. ii, 9p. diagrs., photos., 7 tabs.
(NACA Rept. 1166. Formerly TN 2934)


'AVAILABLE ON LOAN ONLY.
ADDRESS REQUESTS FOR DOCUMENTS TO NACA, 1512 H ST., NW.,
THE REPORT TITLE AND AUTHOR.
iff2r./30o -

S.. ',


The' ionship between adherence and roughness of
between enamel and iron was studied.
-enamel ground coats were prepared and
appi under conditions that gave various degrees
ofl h ence. The variations were produced by
Av ing the amount of cobalt-oxide addition in the
fri (b) varying the type of metallic-oxide addition
e frit, keeping the amount constant at 0.8 weight
percent: (c) varying the surface treatment of the
metal before application of the enamel, by pickling,
sandblasting, and polishing; and (d) varying the time
of firing of the enamel containing 0.8 percent of
cobalt oxide. A positive correlation was found be-
tween adherence and roughness of the interface.

NACA Rept. 1180

THEORETICAL STUDY OF THE TRANSONIC LIFT
OF A DOUBLE-WEDGE PROFILE WITH DETACHED
BOW WAVE. Walter G. Vincenti and Cleo B.
Wagoner. (Portions of this work were reported at
the eighth International Congress on Theoretical and
Applied Mechanics, Istanbul, Turkey, August 20-28,
1952). 1954. ii, 24p. diagrs., 2 tabs. (NACA
Rept. 1180. Formerly TN 2832)

Numerical calculations are described of the aerody-
namic characteristics at small angle of attack of a
thin, doubly symmetrical, double-wedge profile n
the range of supersonic flight speed in which the bow
wave is detached. The analysis is carried out within
the framework of the transonic (nonlinear) small-
disturbance theory. The following results are pro-
vided as functions of the transonic similarity param-
eter: (1) chordwise lift distribution, (2) lift-curve
slope, and (3) position of center of lift.


NACA RM E53E29

IGNITION-DELAY DETERMINATIONS OF
FURFURYL ALCOHOL AND MIXED BUTYL
MERCAPTANS WITH VARIOUS WHITE FUMING
NITRIC ACIDS USING MODIFIED OPEN-CUP AND
SMALL-SCALE ROCKET ENGINE APPARATUS.
Dezso J. Ladanyi, Riley O. Miller and Glen
Hennings. February 1955. 17p. diagrs., photos.,
4 tabs. (NACA RM E53E29)

Approximate linear relations were obtained when the
logarithm of ignition delay was plotted against the
reciprocal of absolute temperature for furfuryl alco-
hol and white fuming nitric acid (16 percent water) in
the small-scale rocket engine (approximately 50 lb
thrust) and for mixed butyl mercaptans and white fuming
nitric acid (2 percent water) in the modified open-cup
apparatus. Zero-temperature coefficients of ignition
delay were obtained for furfuryl alcohol and white
fuming nitric acid (2 percent water) in both apparatus
for the temperature ranges investigated.


WASHINGTON 25, D. C, CITING CODE NUMBER ABOVE EACH TITLE;





2

NACA RM E54K10

SOME MEASUREMENTS OF BOILING BURN-OUT.
Warren H. Lowdermilk and Walter F. Weiland.
February 1955. 18p. diagrs., photo., 3 tabs.
(NACA RM E54K10)

Measurements of boiling burnout heat flux for water
flowing upward through an electrically heated tube
were obtained for ranges of velocity from 0.1 to 19
feet per second; pressure from atmosphere to 2000
pounds per square inch; length-diameter ratios of
25, 37. 5, and 50; and inlet subcooling from zero to
4000 F. Unsteady flow was obtained for burnout
conditions with a restriction located downstream of
the point of burnout. A compressible fluid plenum
chamber located between the restriction and the exit
of the test section resulted in steady-flow burnout
with a tenfold increase in the burnout heat flux.

NACA RM E54L10

MEASURED EFFECTIVE THERMAL CONDUCTIVITY
OF URANIUM OXIDE POWDER IN VARIOUS GASES
AND GAS MIXTURES. J. S. Boegli and R. G.
Deissler. March 1955. 20p. diagrs., tab. (NACA
RM E54L10)
This study was undertaken as part of a series of in-
vestigations to determine the effective conductivity of
U02 powder with a density of 59.5 percent of the den-
sity of the solid U02 at temperatures between 2000
and 15000 F. Experimental effective conductivities
of the gas-powder mixtures were determined for
helium, argon, and nitrogen gases, and mixtures of
helium-argon and xenon-krypton gases. All tests
were performed at a gas pressure above the break-
away pressure, where the thermal conductivity is
independent of pressure. A method for determina-
tion of the relative thermal conductivity of the solid
was devised from knowledge of the effective
conductivity of the powder and the conductivity of the
gases used in the two-phase system. This method
was applied to the U02 used in this investigation.


NACA TM 1340

LIFT ON A BENT, FLAT PLATE. (Auftrieb einer
geknickten ebenen Platte). F. Keune. February
1955. 15p. diagrs. (NACA TM 1340. Trans. from
Bericht der Aerodynamischer Versuchsanstalt
GCttingen. Luftfahrtforschung, Mar. 20, 1936,
Annual Volume, p. 85-87)

The lift on a bent, flat plate is calculated exactly by
the use of conformal mapping. Results are pre-
sented in terms permitting direct determination of
the angle of zero lift, the lift coefficient, and the
lift-curve slope for any flap-chord ratio, flap-
deflection angle, and angle of attack.

NACA TM 1370

SOME MEASUREMENTS OF TIME AND SPACE
CORRELATION IN WIND TUNNEL. (Quelques
Mesures de Correlation Dans le Temps et L'Espace
en Soufflerie). A. Favre, J. Gaviglio and R. Dumas.
February 1955. 21p. diagrs. (NACA TM 1370.
Trans. from La Recherche Aeronautique, no. 32,
Mar. -Apr., 1953, p. 21-28).

Results are presented of research obtained by
means of an apparatus for measurement of time and
space correlation and of a spectral analyser in the


NACA
RESEARCH ABSTRACTS NO. 79

study of the longitudinal component of turbulence
velocities in a wind tunnel downstream of a grid of
meshes. Application to the case of a flat-plate
boundary layer is illustrated. These researches
were made at the Laboratoire de Mecanique de
1'Atmosphere de I'. M. F.M. for the O. N. E. R. A.

NACA TN 3281

INTERGRANULAR CORROSION OF HIGH-PURITY
ALUMINUM IN HYDROCHLORIC ACID. I EFFECTS
OF HEAT TREATMENT, IRON CONTENT, AND
ACID COMPOSITION. M. Metzger and J. Intrater,
Columbia University. February 1955. 38p. photos.,
8 tabs. (NACA TN 3281)

The intergranular corrosion of high-purity aluminum
in hydrochloric acid was studied as a function of iron
content, heat treatment, and acid composition under
conditions where the rate of intergranular penetra-
tion was of the order of 1 millimeter per week. The
behavior of specimens quenched to retain a single-
phase structure indicated the rate of attack on the
high-angle grain boundaries to be influenced by the
segregation in these boundaries of iron and possibly
other impurity atoms.


NACA TN 3322

AN ACCURATE AND RAPID METHOD FOR THE
DESIGN OF SUPERSONIC NOZZLES. Ivan E.
Beckwith and John A. Moore. February 1955.
57p. diagrs., 3 tabs. (NACA TN 3322)

A procedure is given for designing two-dimensional
nozzles in which the streamline coordinates are
computed directly from tabulated flow parameters
and appropriate equations. The method of char-
acteristics was used to obtain the first part of the
flow which consists of a continuous expansion from
a uniform sonic flow to a radial flow. The Foelsch
equations are used for the transition from this radial
flow to the final uniform flow. Information is pre-
sented which enables the designer to select and com-
pute rapidly the wall contour for any nozzle or series
of nozzles for a wide range of length-to-height ratio,
Mach number, and wall angle at the inflection point.


NACA TN 3325

SIMILAR SOLUTIONS FOR THE COMPRESSIBLE
LAMINAR BOUNDARY LAYER WITH HEAT
TRANSFER AND PRESSURE GRADIENT. Clarence
B. Cohen and Eli Reshotko. February 1955. 67p.
diagrs., 2 tabs. (NACA TN 3325)
Stewartson's equations for the compressible laminar
boundary layer with pressure gradient and heat
transfer are solved for pressure gradients varying
from that causing separation to the infinitely favor-
able gradient and for wall temperatures from abso-
lute zero to twice the free-stream stagnation tem-
perature. For the case of favorable pressure gra-
dientswith heated walls, it is shown that the velocity
within a portion of the boundary layer must exceed
the local external velocity. The variation of a
Reynolds analogy parameter, which indicates the
ratio of skin friction to heat transfer, is from zero
to 7.4 for a surface of temperature twice the free-
stream stagnation temperature and from zero to
2.8 for a surface held at absolute zero, where the
value 2 applies to a flat plate.





NACA
RESEARCH ABSTRACTS NO. 79
NACA TN 3330

INGESTION OF FOREIGN OBJECTS INTO TURBINE
ENGINES BY VORTICES. Lewis A. Rodert and
Floyd B. Garrett. February 1955. 23p. diagrs.,
photos. (NACA TN 3330)

The ingestion of foreign objects by vortices formed
between engine inlet and ground surface was inves-
tigated with a 5000-pound-thrust axial-flow jet
engine. Pebbles, typical of objects that damage jet
engines, were projected into the air by the vortices
and were drawn into the engine by the high-velocity
inlet-air stream. Vortex formation depended on
engine speed, engine height, and surface wind.
Pebbles lodged in surface cracks were more readily
picked up than those exposed on a smooth surface.
A motion-picture supplement may be obtained on
loan from NACA Headquarters, Washington, D. C.

NACA TN 3339

EXPERIMENTS ON TURBULENT FLOW THROUGH
CHANNELS HAVING POROUS ROUGH SURFACES
WITH OR WITHOUT AIR INJECTION. E. R. G.
Eckert, Anthony J. Diagiula and Patrick L.
Donoughe. February 1955. 45p. diagrs., photos.,
tab. (NACA TN 3339)

Experiments were conducted to study the flow char-
acteristics along porous rough surfaces with and
without air injection for turbulent flow in a channel.
Four degrees of roughness were studied with ratios
of air-injection velocity to mainstream velocity
from 0 to approximately 0.017. Velocity distribu-
tions along the rough porous surfaces and friction
coefficients are presented.

NACA TN 3340

GENERALIZATION OF GAS-FLOW-
INTERFEROMETRY THEORY AND
INTERFEROGRAM EVALUATION EQUATIONS FOR
ONE-DIMENSIONAL DENSITY FIELDS. Walton L.
Howes and Donald R. Buchele. February 1955. 70p.
diagrs, photos. (NACA TN 3340)

Generalized equations concerned with gas-flow inter-
ferometry are applied in developing interferogram
evaluation equations for one-dimensional density
fields. Theoretical limitations and systematic
errors of the equations are investigated. Criteria
for applicability and for avoiding apparent-ray-trace
crossing are presented. The theory indicates that
errors caused by an extended light source and test-
section windows are negligible in practice. Analyti-
cal and experimental checks of the validity of the
evaluation equations are presented. Theoretical
results are compared with those of previous analyses.


NACA TN 3352

EXPERIMENTAL INVESTIGATION OF MISALINING
COUPLES AND ECCENTRICITY AT ENDS OF MISA-
LINED PLAIN BEARINGS. G. B. DuBois, F. W.
Ocvirk and R. L. Wehe, Cornell University.
February 1955. 81p. diagrs., photo., 3 tabs. (NACA
TN 3352)

An experimental investigation was conducted to
study the behavior of full journal bearings under
steady load when acted on by a steady misalining
couple. Displacements of the ends of the journal
axis were measured with either an axial couple


3

applied in the plane of the central load or a twisting
couple in the plane normal to the central load. Oil-
flow-rate and bearing-temperature measurements
were also made to determine the effect of misalining
couples on these quantities.

NACA TN 3355

PRELIMINARY INVESTIGATION OF A STICK
SHAKER AS A LIFT-MARGIN INDICATOR. James
P. Trant, Jr. February 1955. 19p. diagrs.,
photos. (NACA TN 3355)

Preliminary tests with simulator equipment were
made to determine the ability of subjects to use
frequency or amplitude of vibration of the pilot's
control stick, or both, as an indicator for maintain-
ing a desired lift margin below the stall. The re-
sults showed that the desired lift margin could prob-
ably be maintained, provided the allowable variation
from the desired angle of attack or lift coefficient
produced either changes in amplitude of vibration of
about 100 percent or changes in frequency of 40 per-
cent, or both.

NACA TN 3368

ANALYSIS OF BEHAVIOR OF SIMPLY SUPPORTED
FLAT PLATES COMPRESSED BEYOND THE
BUCKLING LOAD INTO THE PLASTIC RANGE.
J. Mayers and Bernard Budiansky. February 1955.
44p. diagrs. (NACA TN 3368)

An analysis is presented of the postbuckling behavior
of a simply supported square flat plate with straight
edges compressed beyond the buckling load into the
plastic range. The method of analysis involves the
application of a variational principle of the deforma-
tion theory of plasticity in conjunction with computa-
tions carried out on a high-speed calculating ma-
chine. Numerical results are obtained for several
plate proportions and for one material. The results
indicate plate strengths greater than those that have
been found experimentally on plates that do not
satisfy straight-edge conditions.

NACA TN 3369

MINIMUM-DRAG BODIES OF REVOLUTION IN A
NONUNIFORM SUPERSONIC FLOW FIELD. Conrad
Rennemann, Jr. February 1955. 25p. diagrs.
(NACA TN 3369)

A general expression for the cross-sectional-area
distribution of the minimum-drag body of revolution
of given volume and length in a nonuniform super-
sonic flow field is derived on the basis of Linearized
theory. This result is applied to the determination
of the minimum-drag body of revolution of given
volume and length located in the flow field of a
parabolic body of revolution. The interference
pressures from a main body acting on a satellite
body have a negligible effect on the shape for mini-
mum wave drag of the satellite body.


NACA TN 3371

ANALYSIS OF ACCELERATIONS, GUST VELOCI-
TIES, AND AIRSPEEDS FROM OPERATIONS OF A
TWIN-ENGINE TRANSPORT AIRPLANE ON A
TRANSCONTINENTAL ROUTE FROM 1950 TO 1952.
Thomas L. Coleman and Walter G. Walker.
February 1955. 16p. diagrs., 3 tabs. (NACA
TN 3371)





4

VGH time-history data obtained from one type of
twin-engine transport airplane during operations
from 1950 to 1952 on a transcontinental route are
analyzed in order to determine the magnitude and
frequency of occurrence of gust accelerations, gust
velocities, and the associated airspeeds and alti-
tudes. The present results compared favorably with
results previously obtained for a similar type of twin-
engine airplane during other operations. The pres-
ent operations indicate a less severe acceleration
history than that shown for the other airplane,
apparently because of the lower operating airspeed
in rough air.


NACA TN 3389

AXIALLY SYMMETRIC SHAPES WITH MINIMUM
WAVE DRAG. Max. A. Heaslet and Franklyn B.
Fuller. February 1955. 46p. diagrs. (NACA
TN 3389)

Optimum bodies consisting of a basic cylinder with
added peripheral volume are derived and presented
in terms of the effective radius-length ratio. Varia-
tion of this parameter from 0 to = encompasses the
spectrum of results from slender to two-dimensionaL
A reciprocal theorem leads to simple interpretations
of variational problems.


NACA TN 3396

ICING LIMIT AND WET-SURFACE TEMPERATURE
VARIATION FOR TWO AIRFOIL SHAPES UNDER
SIMULATED HIGH-SPEED FLIGHT CONDITIONS.
Willard D. Coles. February 1955. 33p. diagrs.,
photos. (NACA TN 3396)

The variation of wet-surface temperature and the
conditions that will result in ice-free surfaces for
high-speed flight through clouds were investigated
experimentally. The results are compared with
calculated values obtained with an analytical method..
The analytical results were generally conservative,
giving wet-surface temperatures 20 to 40 F lower
than the experiments and predicting the formation of
ice at values of ambient-air temperature up to 120 F
higher than the experiments. The location of ana-
lytically determined critical regions on the bodies
for the initial formation of ice was experimentally
substantiated.



NACA TN 3397

AN EVALUATION OF NON-NEWTONIAN FLOW IN
PIPE LINES. Ruth N. Weltmann. February 1955.
40p. diagrs., tab. (NACA TN 3397)

An analysis is presented of a method for determining
pressure losses due to the flow of non-Newtonian
materials in pipe lines by using basic flow data
obtained from measurements of flow curves, which
are rate-of-shear shearing-stress curves. The
advantages of properly designed rotational visco-
meters over capillary viscometers for measuring
these flow curves and interpreting them to obtain the
basic flow parameters are discussed. Dimension-
less parameters are calculated from these basic
flow data and are used to construct a generalized
friction diagram to describe the flow characteristics
of Newtonian and non-Newtoruan materials in pipe
lines.


NACA
RESEARCH ABSTRACTS NO. 79
NACA TN 3398

A THERMAL EQUATION FOR FLAME QUENCHING.
A. E. Potter, Jr. and A. L. Berlad. February 1955.
18p. diagrs, tab. (NACA TN 3398)

A thermal quenching equation is derived; the equa-
tion is essentially an extension of a previously pro-
posed diffusional concept. By proper choice of the
rate-controlling chemical reaction, the equation be-
comes suitable for use with rich as well as lean fuel-
air mixtures. The equation was tested, using pub-
lished quenching-distance data for propane-oxygen-
nitrogen flames, which include the effect of oxygen-
nitrogen ratio, equivalence ratio, pressure, and ini-
tial temperature.

NACA TN 3402

BOUNDARY LUBRICATION OF STEEL WITH
FLUORINE- AND CHLORINE-SUBSTITUTED
METHANE AND ETHANE GASES. S. F. Murray,
Robert L. Johnson and Max A. Swikert. February
1955. 17p. photos., diagrs., 2 tabs. (NACA
TN 3402)

Sliding-friction experiments were made with steel
surfaces in atmospheres of halogenated gases.
Under the conditions of this investigation, the most
stable or fully fluorinated gases gave no surface
protection. Several fluornnated compounds contain-
ing two or more chlorine atoms per molecule served
as effective boundary lubricants (reduced friction
and prevented excessive wear, surface welding, and
metal transfer) in a manner comparable with a
conventional Liquid lubricant. Run-in procedure,
bearing materials, and moisture availability appear
to be critical in boundary lubrication by gaseous
materials.

NACA TN 3405

TEMPERATURE-COMPOSITION LIMITS OF SPON-
TANEOUS EXPLOSION FOR NINE ALKYLSILANES
WITH AIR AT ATMOSPHERIC PRESSURE. Rose L.
Schalla and Glen E. McDonald. February 1955.
13p. diagrs. (NACA TN 3405)

To provide sale-handling information, the spontane-
ous explosion limits of nine alkylsilanes were deter-
mined as a function of temperature and fuel-air com-
position at a pressure of I atmosphere. Over a fuel
concentration range of about 2 to 9 percent by vol-
ume, the fuels studied were nonexplosive below the
following temperatures: telramethylsilane
(CH3)4Si, 4500 C; trimethylsilane (CH3)3SiH,
3000 C; diethylsilane (C2H5)2SiH2, 2550 C;
dimethylsilane (CH3)2SiH2, 2200 C; ethylsilane
(C2H5)SiH3. 2150 C; isobutylsilane (i-C4Hg)SiH3,
2000 C; n-butylsilane (n-C4H9)SiH3, 1850 C;
methylsilane (CH3)SiH3, 1250 C; and vinylsilane
H2C = CH-SiH3, 900 C.

NACA TN 3409

CHAIN BREAKING AND BRANCHING IN THE
ACTIVE-PARTICLE DIFFUSION CONCEPT OF
QUENCHING. Frank E. Belles and A. L. Berlad.
February 1955. 37p. diagrs, 3 tabs. (NACA
TN 3409)

General quenching-distance equations that take into
account gas-phase chain breaking and branching and





NACA
RESEARCH ABSTRACTS NO. 79
the effect of the wall efficiency for destruction of
active particles are derived as extensions of the
original simple theory of quenching by diffusion of
active particles. The general characteristics of the
equations are discussed. Quenching distance data
from the literature for propane-oxygen-nitrogen
mixtures are treated in a consistent manner. The
effects of elevated initial mixture temperature are
predicted and agree qualitatively with observed
trends. It is lound that the simple theory correlates
all the data satisfactorily.


BRITISH REPORTS

N-34309'

Royal Aircraft Establishment (Gt. Brit.)
METHODS OF DETERMINATION AND OF FIXING
BOUNDARY LAYER TRANSITION ON WIND TUNNEL
MODELS AT SUPERSONIC SPEEDS. K. G. Winter,
J. B. Scott-Wilson and F. V. Davies. September
1954. 27p. diagrs., photos. (RAE Tech. Note
Aero 2341)

An account is given of methods used in supersonic
wind tunnels for observation of boundary-layer
phenomena, in particular of the sublimation and oil
film techniques. Examples are given of the uses of
these techniques. On the fixing of transition, a
rough guide is given for the minimum size of wire
required, with an example of the use of wires. The
results of a brief experiment on the profile of an
artificially promoted turbulent boundary layer are
given.

N-34820'

Royal Aircraft Establishment (Gt. Brit.)
SOME NOTES ON A PROPOSAL TO USE A BLOWER
TUNNEL FOR VISION IN RAIN TESTS ON AIRCRAFT
WINDSCREENS. F. J. Bigg. September 1954. 16p.
diagrs., 2 tabs. (RAE Tech. Note Mech. Eng. 187)

For research work on vision through aircraft wind-
screens in rain, it has been suggested many times
that ground tests should be made using a blower tun-
nel with simulated rain. This note describes some
tests and calculations, which have recently been
made, from which it has become apparent that it is
"'not poEsible to produce realistic rain conditions by
this method. The possibility of using a large vertical
wind tunnel has also been considered theoretically
and it is concluded that this would also be imprac-
ticable.


N-34821*

Royal Aircraft Establishment (Gt. Brit.)
DEVELOPMENT OF AN AIR MASS-FLOW RATE
METER. W. J. G. Cox. October 1954. 47p.
diagrs., photos. (RAE Tech. Note Instn. 142)

The development of an air mass flow rate meter to
cover a very wide range is described which, es-
sentially an analogue computer, gives a two-sweep
pointer direct presentation of air mass flow rate,
independent of pressure, temperature, and velocity
changes within the range of the instrument. The
pointers are driven by a servo system which is
error-actuated from the computing bridge network,
secondary feedback being employed to maintain
stability with a saturated angular output rate of ap-


5

proximately 330 per second. Specifications and
performance figures are given for the individual
transducer elements and the complete instrument.
error estimationsare made, and the servo stability
is discussed.

N-34849'

Royal Aircraft Establishment (Gt. Brit.)
THEORETICAL LOAD DISTRIBUTIONS ON FIN-
BODY-TAILPLANE ARRANGEMENTS IN A SIDE-
WIND. J. Weber and A. C. Hawk. August 1954.
113p. diagrs., 6 tabs. (RAE Aero 2518)
A theory is developed for calculating thedistributions
of side force and lift on fin-fuselage-tailplane ar-
rangements in a sidewind but with the tailplane set at
zero angle of attack. The results can be extended to
other arrangements and to compressible subcritical
flow and are required for stability and stressing
analysis. This paper is a continuation of a report in
which the interference between fin and fuselage was
considered. The addition of the tailplane brings
changes in the load distribution as well as in the
overall forces. The main functions needed for rep-
resentative cases are given in tables and charts.
Results for other geometrical arrangements can be
obtained by interpolation.


N-34878'

Aeronautical Research Council (Gt.Brit.)
THE CRITICAL WHIRLING SPEEDS AND NATURAL
VIBRATIONS OF A SHAFT CARRYING A SYM-
METRICAL ROTOR. E. Downham. 1954. 13p.
diagrs., photo. (ARC R. M 2854; ARC 13,917.
Formerly RAE Structures 97)

The experiments described in this report are part of
a program of model experiments designed to estab-
lish an accurate method for calculating the critical
whirling speeds of complex systems. The critical
whirling speeds and natural vibrations of a single
shalt flexibly supported and carrying a flexible rotor
of appreciable moment of inertia have been investi-
gated and good agreement has been obtained between
experimental and calculated results for the rotating
system.


N-34879'

Aeronautical Research Council (Gt. Brit.)
THE INFLUENCE OF ROLLING MOMENTS ON
SPIN RECOVERY AS OBSERVED IN MODEL-
SPINNING TESTS. D. J. Harper. 1954. 13p.
diagrs., tab. (ARC R& M 2831: ARC 13,538.
Formerly RAE Aero 2365)

Several aspects of model-spinning test technique
have been brought into prominence by full-scale
developments. Correlation between model and full-
scale recoveries has been poor in some cases, and
it appears that full-scale recovery may depend on
some other means in addition to the normal use of
rudder and elevator. Analysis of data shows the
effects of applied rolling moments and of aileron
deflections on both spin and recovery to be closely
related to the distribution of loading of the aircraft.
The ordinary model-test result can be in error due
to scale effects on rolling moments. This report
collects the available model data on the effects of
applied rolling moments, and also includes model
data on the use of ailerons to assist recovery.





6

N-34880*

Aeronautical Research Council (Gt. Brit.)
THEORETICAL SUPERSONIC DRAG OF NON-
LIFTING INFINITE-SPAN WINGS SWEPT BEHIND
THE MACH LINES. T. Nonweiler. 1954. 22p.
diagrs., 3 tabs. (ARC R & M 2795; ARC 13,896.
Formerly RAE Tech. Note Aero 2073)

The wing sections assumed to be arbitrary but
identical over the entire wing span. The drag is
found according to the linear equations of supersonic
flow by considering the flow due to a system of
superposed source planes. The drag is found to be
finite and the effect of the speed of flight independent
of the section shape assumed. The variation of drag
with the section shape is shown to be proportional to
the integral over the chord of the product of the
local wing thickness and the value of the excess
pressure existing in incompressible flow at the same
position. Methods of reducing drag by changing the
section shape are considered.

N-34928*

Royal Aircraft Establishment (Gt. Brit.)
TRIALS OF 3 FT. DROGUE TARGET. D. R.
Bettison and A. Eldridge. August 1954. 14p.
diagrs., photo., 4 tabs. (RAE Tech. Note Mech.
Eng.185)

It was established by flight trials that the 1-ft 6-in.
throat x 3-ft tail x 15-ft long'drogue target manufac-
tured in R. F. D. 3272/N nylon rip-stop is satisfactory
for speeds up to 300 kts I. A. S. D. T. D. 778 material
is inadequate for present requirements for all drogue
sizes, and it recommended that it be replaced by a
stronger material.

N-34929*

Royal Aircraft Establishment (Gt. Brit.)
SOLUTION OF AERO-ELASTIC-PROBLEMS BY
MEANS OF INFLUENCE COEFFICIENTS. D.
Williams. November 1954. 12p. diagr. (RAE
Structures 169)

It is shown that, on the basis of the data provided by
two sets of influence coefficients for a wing (or other
surface) and "elastic" set giving deflections (and
hence incidence angles) in terms of applied loads,
and an aerodynamic set giving aerodynamic loads in
terms of incidence angles all "static" aeroelastic
problems can easily and expeditiously be solved by
the use of a digital computer. It is also suggested
that the same method of approach may well be used
for solving oscillatory aeroelastic problems such as
flutter.

N-34930*

Nat. Gas Turbine Establishment (Gt. Brit.)
A NOTE ON THE COOLING OF TURBINE ROTOR
BLADES BY WATER JETS. K. R. F. Kenworthy.
October 1954. 6p. (NGTE Memo. M. 227)

Experimental work at N. G. T.E. on "spray" or "jet"
cooling is reviewed and a performance estimate
given in comparison with air cooling. It is shown
that the gains realizable as a result of the higher
maximum cycle temperature are much the same in
the two cases. The detrimental effects of the water
and, in aircraft applications, the weight of water to
be carried lead to the conclusion that spray cooling
is inferior to air cooling.


NACA
RESEARCH ABSTRACTS NO. 79
N-34931*

Royal Aircraft Establishment (Gt.Brit.)
THE SLIP BAND EXTRUSION EFFECT IN COLD
ROLLED, SUPER PURITY ALUMINUM. C. A.
Stubbingtoi and P. J. E. Forsyth. October 1954.
7p. photos. (RAE Tech.Note Met.205)

It has been found that by cold rolling pure aluminum
to a suitable degree, a slip band extrusion effect can
be produced by subsequent fatigue stressing. This
effect has been shown to be due to local recrystalli-
zation producing soft regions along slip striations,
and is analogous to the soft regions produced in alu-
minum -4 percent copper by accelerated averaging
under the action of fatigue stresses.

.N-34934*

Royal Aircraft Establishment (Gt. Brit.)
INTRODUCTORY NOTES TO THE PROBLEMS OF
AERODYNAMIC HEATING. R. J. Monaghan.
October 1954. 19p. diagrs. (RAE Tech. Note
Aero 2346)

This note gives a simplified discussion of the aero-
dynamic heating problems encountered in high-speed
flight, illustrates their magnitude, and considers
some means of alleviation. Although the tempera-
tures for zero heat transfer between airstream and
aircraft increase rapidly with increase of flight
speed, some alleviation can be obtained by choosing
a surface finish which loses heat freely by radiation.
In addition, small thicknesses of external insulation
could be extremely effective in protecting the main
structure and the amounts of heat which enter the
interior of the aircraft need not be excessive.


N-34936*

Royal Aircraft Establishment (Gt.Brit.)
AN ELECTROLYTIC METHOD FOR THE DIRECT
PRODUCTION OF MAGNESIUM LITHIUM ALLOYS
FROM LITHIUM CHLORIDE. J. Smolinski, J. C.
Hannam and A. L. Leach. October 1954. 19p.
diagrs., photos., 9 tabs. (RAE Met.80)

Magnesium lithium alloys were made directly at high
current efficiency by electrolytic deposition of lith-
ium on to a magnesium cathode from a molten
50 LiCl/50 KC I or 75 LC 1. 25 BaCz2 electrolyte at
5600 to 6300 C. The relation between sodium con-
tamination in electrolyte and product has been deter-
mined. By careful selection of cell materials to
avoid sodium contamination, alloys ductile m the
aged condition could be made directly without need
of refining.


N-34937*

Royal Aircraft Establishment I(G. Brit.)
A RATE GYRO FOR USE IN AIRCRAFT DYNAMIC
RESPONSE WORK. Keith Smith. October 1954.
13p. diagrs., photos. (RAE Tech. Note Aero 2327)

An instrument to measure angular rate under dynamic
conditions, used in conjunction with a galvanometer
recorder, has been developed from the existing
standard instrumentation rate gyro (Type IT 2-1).
With a range of 180 per second, it has considerably
improved dynamic response characteristics. Tests
on an oscillating table indicate that the response is
flat (2 percent of static value) up to 8 cycles per





NACA
RESEARCH ABSTRACTS NO. 79

second for an amplitude of t60 per second. Tests at
a smaller amplitude were impractical but it is
suspected that under these conditions the presence of
nonlinear dynamic characteristics might cause a less
satisfactory response.

N-349381

Royal Aircraft Establishment (Gt.Brit.)
THE DETERMINATION OF MAGNESIUM OXIDE IN
MAGNESIUM. H. J. Allsopp. October 1954. 10p.
diagr., 6 tabs. (RAE Met. 79)

In the method described, magnesium metal is re-
moved by sublimation in vacuum, the residue dis-
solved in acid, and the magnesium content deter-
mined volumetrically by disodium ethylene diamine
tetra-acetate.


N-34939"

Royal Airoraft Establshment (G. Brit.)
GEOMETRICAL ANALYSIS OF SCHLIEREN PHOTO-
GRAPHS OF THE FLOW IN THE PLANE OF IN-
CIDENCE OF INCLINED CONE-CYLINDERS AT
SUPERSONIC SPEEDS. K. G. Winter. November
1954. 15p. diagrs., photo., tab. (RAE Tech. Note
Aero 2345)

Measurements have been made of shock wave posi-
tions shown on schlieren photographs of the flow past
inclined cone-cylinders. The resulting angles and
distances have been correlated to give a general
method of estimating the positions of the nose shock
waves. The method is satisfactory at Mach numbers
between 1.4 and 2.0 for cone-cylinders of semiangle
less than 150, at incidences up to 300, and is of use
in the design of models for supersonic wind tunnels.


N-34950

Royal Aircraft Establishment (Gt. Brit.)
AN INTEGRATING AMPLIFIER FOR INSTRUMEN-
TATION. E. T. de la Perrelle. September 1954.
18p. diagrs. (RAE Tech. Note Instn. 144)

The note discusses the use and design of amplifiers
the output of which resembles, in essential features,
the integrand with respect to time of the input. The
relations between the gain and phase displacement
versus frequency characteristics required to produce
the desired result are shown to be a compromise,
which is realizable in practice. A feedback integra-
tor, which attenuates at frequencies below the lower
limit of integration, is analyzed and discussed.


N-34951*

Royal Aircraft Establishment (Gt.Brit.)
ACCURACY AND SLIP TESTS PERFORMED ON A
SINE AND COSINE BALL RESOLVER. B. Pounder.
October 1954. 12p. diagrs., photo. (RAE Tech.
Note IAP 1034)

A description is given of the methods used and the
results obtained from the tests performed on a 1-
inch ball resolver under development by LAP depart-
ment. The following tests were performed: ac-
curacy of resolution on no load; percentage slip of
the output shafts for several applied torques and
different angles; and the torque required to drive
the input shaft for several values of the output load.


7

N-34953*

Royal Aircraft Establishment (Gt. Brit.)
NOTES ON THE INTERNATIONAL SYMPOSIUM ON
MACROMOLECULAR CHEMISTRY HELD AT MILAN
AND TURIN, 26TH SEPTEMBER 2ND OCTOBER,
1954. W. W. Wright. November 1954. 19p. (RAE
Tech. Note Chem, 1239)

General comments on a group of papers being fol-
lowed by more detailed accounts of those papers ap-
pearing to the author to be of greater interest are
given. A List of all the papers presented at this
conference on macromolecular chemistry is given,
and those available as preprints are marked.

N-34956*

Royal Aircraft Establishment (Gt. Brit.)
A GENERAL METHOD (DEPENDING ON THE AID
OF A DIGITAL COMPUTER) FOR DERIVING THE
STRUCTURAL INFLUENCE COEFFICIENTS OF
AEROPLANE WINGS. D. Williams. November
1954. 32p. diagrs., tab. (RAE Structures 168)

A general method (requiring the aid of a digital com-
puter) is described for deriving the influence coef-
ficients of any type of wing, and hence for evaluating
its strength and stiffness characteristics. The
method allows for shear deflections, and hence
implicitly takes account of effects like shear-lag and
warping of wing cross-sections. A rapid method
accurate enough to serve as a basis for dynamical
calculations is first described, and secondly a more
rigorous method on which to base final stressing of
the structure.

N-34957*

Royal Aircraft Establishment (Gt. Brit.)
STUDIES OF FLAMES BURNING WITH CHLORINE
TRIFLUORIDE. G. Skirrow, R. A. M. Straker and
H. G. Wolfhard. September 1954. 19p. diagr.,
photos., tab. (RAE RPD 22)

Diffusion flames are described in which fuels such as
hydrogen, carbon monoxide, carbon disulphide,
water, ammonia, hydrocarbons, and organic halides
are burnt with chlorine trifluoride. Chemical equi-
librium is nearly established in the main reaction
zone as in an oxygen diffusion flame but the chlorine
trifluoride flames possess several unusual features.
Carbon formation is very heavy with hydrocarbon
fuels and it may even impair combustion. Radicals
such as C2 and CN have an unusually long lifetime
and their presence in a high-temperature region en-
hances the luminosity of some of the flames. It is
suggested that the persistence of these radicals may
be due to the very rapid diffusion of hydrogen intothe
main reaction zone which effectively prevents the
penetration of fluorine to the fuel side of the flame.


N-34959*

Royal Aircraft Establishment (Gt. Brit.)
THE CALCULATION OF THE PRESSURE DISTRI-
BUTION ON THICK WINGS OF SMALL ASPECT
RATIO AT ZERO LIFT IN SUBSONIC FLOW. J.
Weber. September 1954. 66p. diagrs., 4 tabs.
(RAE Aero 2519)

The method of expressing the velocity increment
over airfoils directly in terms of the section ordi-
nates is extended to cover also straight and swept





8

wings of finite aspect ratio. The wings considered
are untapered in plan form but may be tapered in
thickness. The section can be of any given shape.
Coefficients required in the calculation are tabulated
for the center section of straight and sweptback
wings of aspect ratios 0.5, 1, 2, and 4. The re-
maining calculations can be made very quickly.
Since wings of very small aspect ratio can be treated
also by the method of slender-body theory, the re-
lations between linear theory, slender-body theory,
and linearized slender-body theory are discussed.

N-34964*

Royal Aircraft Establishment (Gt.Brit.)
THE EFFECT OF ASPECT RATIO ON THE CHORD-
WISE LOAD DISTRIBUTION OF FLAT AND CAM-
BERED RECTANGULAR WINGS. J. Weber. October
1954. 40p. diagrs., 2 tabs. (RAE Aero 2525)

The report deals with the "first problem" of airfoil
theory, that of determining the shape of the airfoil
for a given load distribution. The downwash integral
over wing and wake, which is involved in this calcu-
lation, is reduced to a very simple form which per-
mits a rapid numerical evaluation for wings of rec-
tangular plan form. This method has been used to
check the accuracy of the results of various methods
of calculation for small aspect ratio plane rectangu-
lar wings by inserting the calculated load distribu-
tions into the downwash equation and determining
the airfoil shape which is then compared with the
plane wing, for which the load distribution was cal-
culated.


N-34965*

Royal Aircraft Establishment (Gt. Brit.)
THE PRESSURE DISTRIBUTION, (ACCORDING TO
THE LINEAR THEORY), ON THE GROUND DUE TO
A DELTA WING IN STEADY LEVEL SUPERSONIC
FLIGHT. G. M. Roper. November 1954. 45p.
diagrs. (RAE Tech. Note Aero 2332)

Effects of angle of attack and thickness are calculat-
ed separately, and the results are superimposed.
Calculations are made for delta wingsof single-wedge
section and double-wedge section. The results are
given in graphic form. The results can only be
expected to give a very rough indication of the actual
pressure distribution, since the fluid medium is as-
sumed to be homogeneous, and no account is taken
of shock waves. More recent work suggests that, in
general, the pressures are overestimated. In par-
ticular, no significance should be attached to the
very high pressures that occur in the very small
region immediately behind the Mach wave from the
trailing edge.

N-34966"

Royal Aircraft Establishment (Gt. Brit.)
THE EFFECT OF LOW TEMPERATURES ON THE
FATIGUE AND TENSILE PROPERTIES OF SOME
LIGHT ALLOYS, NOTCHED AND UNNOTCHED.
N. J. F. Gunn. October 1954. 40p. diagrs., photo.,
20 tabs. (RAE Tech.Note Met.207)

Fatigue and tensile tests have been made on six light
alloys at room and sub-zero temperatures, to ascer-
tain the increase in properties at the low tempera-
tures. The materials used were aluminum alloys
D.T.D. 683, D.T.D. 363A, D.T.D. 364B (with two dif-


NACA
RESEARCH ABSTRACTS NO. 79
ferent heat treatments) magnesium alloy Z3Z, and a
12 percent magnesium lithium binary alloy. It was found
that the fatigue and tensile properties did improve at
the low temperatures, but the percentage increase
was not very great. UNIVERSITY OF FLORIDA

S1N-34968 11111 II
3 1262 08153 294 6
Ministry of Supply (Gt. trit. I
EXPERIENCE OF FATIGUE AT WEYBRIDGE. H. H.
Gardner. (Part one of final report prepared by
Vickers-Armstrong, Ltd., Weybridge). November
1954. 37p. diagrs., photo. (Ministry of Supply.
S & TM 10/54)

During 1942-44 a number of fatigue failures occurred
on Welhngton aircraft in service. The majority of
failures occurred in main spar booms on the tension
flanges, resulting in all cases in the loss of the air-
craft and the complete crew. This report outlines
the causes of these failures and describes the steps
which were taken to modify the design, together with
the experimental evidence which led to the final form
of modification adopted. It is decided that the detail
design of the joint was responsible for high stress
concentrations at the base of the serrations, and the
material of the spar tubes due to the method of man-
ulacture contained high initial tension stresses which
increased the tension stresses at the serrations to
serious proportions.







MISCELLANEOUS


NACA TN 3263

Errata on "LIFT AND MOMENT EQUATIONS FOR
OSCILLATING AIRFOILS IN AN INFINITE UNSTAG-
GERED CASCADE. Alexander Mendelson and
Robert W. Carroll. October 1954.





UNPUBLISHED PAPERS


N-35236*

Cornell University, Graduate School of Aeronautical
Engineering. THE KINETIC ASPECT OF PLASTIC-
ITY. C. Riparbelli. February 1954. 68p. diagrs.,
photo. (Cornell University, Graduate School of
Aeronautical Engineering)

The aim of the present paper is that of collecting
some of the information available on plastic flow,
with particular attention to plastic flow in copper and
to its relation to the stress and strain, in order to
explain some phenomena observed in the propagation
of strain in a bar undergoing longitudinal impact and
to eliminate an apparent contradiction between two
groups of data.


NACA-Langley 3-11-55 41 :

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