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CONFIDENTIAL

Approved for public release; distribution isunlimited.

Distribution authorized to U.S. Gov't. agenciesand their contractors;Administrative/Operational Use; 31 MAR 1953.Other requests shall be referred to NationalAeronautics and Space Administration,Washington, DC.

28 Jan 1957 per doc markings ; NASA per DTICform 55

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Armed Services lectinical Information llpncy

Reproduced by •■ ■

CLASSIFICATION CHANGED TO UNCLASSIFIED

BY MdtocUsrtfiMtlfln Notlc. No. Ill <lat«d 28 January I937i a^.tu u«t «,. i« ^

Date -mi 1 •' i7 Signed QJUJX KttJy C)FFICE SECURITY ADVISOR

NOTICE: WHEN GOVERNMENT OR OTHER DRAWDfOB, SPECinCATIONS OR OTHER C4TA ARE USED FOR ANY PURPOSE OTHER THAN IN CONNECTION WITH A DEFTNTELY Ri LATED GOVERNMENT PROCUREMENT OPERATION, THE U. S. GOVERNMENT THEREBY INCl' ^ NO RESPONSIBILITY, NOR ANY OBLIGATION WHATSOEVER; AND THE FACT THAT TLIS GOVERNMENT MAY HAVE FORMULATED, FURNISHED, OR IN ANY WAY SUPPUED THü, SAID DRAWINGS, SPECIFICATIONS, OR OTHER DATA IS NOT TO BE REGARDED BY IMPLICATION OR OTHERWISE AS IN ANY MANNER LICENSING THE HOLDER OR ANY OTHER PERSON OR CORPORATION, OP CONVEYING ANY RIGHTS OR PERMISSION TO MANUFACTURE USE OR SELL ANY PATENTEF INVENTION THAT MAY IN ANY WAY BE RELATtD THERETO '

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CURITV I INFO RfVI AXIOM

CONFIDENTIAL -oiy 0

m oL^DOi ,

/»*z

EARCH MEMORANDUM for the

Bureau of Acouautics, Depertaent of the Navy

WIND-TUNNEL INVBSTIQATION AT LOW SPEED OF THE YAWMJO

STABILITY DERIVATIVES OF A l/9-SCALE POWERED MODEL

OF THE COHVAIR XFY-1 VERTICALLY RISING AIRPLAhK

TED NO. NACA DE 37?

By M. J. (Jueljo, W. D. Wolhart, and H. S. Fletcher

Lan^ley Aeronautical Laboratory Langley Field, Va.

Thi« DAtarlil ronuliM intormatlon Btv-tln^ (he rtatlnrwl [*'mnm» of Ih» ■ 'r.Ht-d JtttM within U» nwuünc of tt. «aptoMc* taw8. T11*» I9. lJ •s . :,*c«- W ■irf "W, Uw tranomUMon or rcwUtloo :>f which in »n> mAnnwr to ut unAuthorUvd [iwraon !'■ j r Mill»J u»

NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

WASHINGTON MAR ."I 1053

CONFIDENTIAL

IKMIW^

NACA m SL^5I>01 COflFIDENTLAL

NATIONAL ADVISORY JOMMITTEE FOR AERONAUTICS

RESEARCH MEMORANDCK

for the

Bureau nf Aeronautic a^ Department of the Navy

'.rjfD-TUNNEL INVESTIGATIOH AT LOW SPSED OF THE YAWING

STABILITY EERIVATIVES OF A 1/9-8CAIJ5 POWERED MCDEL

OF THE COHVAIR XFf-1 VERTICALLY RISING AIRPLANE

TED NO. NACA IK 575

By M. J. Queijo, W. D. Wolhart, and H. S. Fletcher

SlÄt<ARY

An experimental investigation has been conducted in the Langley stability tunnel at low speed to determine the yawing stability derivn- tlvej of a l/9-8cale powered model of the Convair XFJf-1 vertically rising airplane. Effects of thrust coefficient were investigated fo*' the complete model and for certain conpoaänts of the model. Effects of control deflec- tions and of propeller blade angle were investigated f^r the compiete model. Most of the tests were made through an angle-of-attack range f re n about -U0 to 29°, and the thruat coefficient range was from 0 to 0.7.

In order to expedite dlotrlbution of these data, no analysis of the data has been prepared for this.

(

HfTRODUCTIOK

Various Investigations have shown tnat the dynamic stability ohar- acterlstlcs of high-speed aircraft are critically dependent on certain mass and aerodynamic parametere and, hence, that reliable estimates of the dynamic stability of euch aircraft can be made only If these param- eters are dotemlned accurately. The purpose of tJvc present Investigation was to determine the yawing stability derivatives of a powered model of *he Convair 1L.1-1 vertically rising airplane from a series of low-3peed tests in the Langley stability tunnel. These tests were made at tlie

CONFIDENTIAL

. i»-

COKFIEENTIAL NACA RM SL'35D31

request of the Bureau of Aeronautics to aid In the development of the XPY-l airplane. The. results of a previous Investigation to deteraine the static longitudinal and lateral stability derivatives of the same model are given in reference 1.

SYMBOLS AHD COEFFICIENTS

The data presented herein are in the form nf standard NACA coef- ficients of forces and monsnts which are referred to the system of stability axe* (fig. 1) with the origin at the projection on the plane of syanetry of the l^-percent point of the wing mean aerodynamic chord, nils systein of axes is defined as an orthogonal system having the origin at the asaiBBd center of gravity and in which the Z-axle is in the plane of symnetry and perpendicular to the relative wind, the X-axis 1E in the plane of synmetry and perpendicular to the Z-axis, and the Y-axis is perpendicular to the plane of synanetry. Positive directions of forces, moments, and displacements are shown in figure 1.

b theoretical wing span, 2.66 ft

d local propeller blade chord, ft

h amxiMua blade thickness at local chord, ft

D propeller diameter, ft

q dynamic pressure, H>V2> Ib/sq ft

r0 radial distance from propeller hub center line, ft

r yawing angular velocity, radians per second

R propeller radius, 0.889 ft

S area of theoretical wing, U.27 aq ft

V free-stream velocity, ft/sec

a wing angle of attack, deg

ß sideslip angle, rad

[ßo)y front propeller blade angle measured at 0.7^ ", deg

7 angle of climb, deg

CONFIDENTIAL

u: : Be

•••• &R

T-: ♦ •••• • •••• e

i p

■ L

X

Y

NACA RM SL53D01 CONFIDENTIAL ?

elevator deflection, positive trailing edge up, deg

rudder deflection, positive trailing edge to right, deg

angle of yaw, deg

local blade angle, d«?p

angle of roll, deg

mass density of air, slugs/cu ft

lift, lb

longitudinal force, Lb

side force, lb

thrust, lb (T - Xpropenere on - Vopejj^g off, for complete model at a ■ u0)

vtiwlns »nompnt. ft-lb

rolling moment, ft-lb

lift coefficient, L/qS

side-force coefficient, Y/qS

thrust coefficient, T/qS

yawlng-manent ccxjfflclent, N/qSb

yawing velocity parameter

rolling-mcaent coefficient, l/qSb

%

N

I

CL

Cy

V Cn

rb 2V

Cl

^r c)2V

C, T rb

I

CONFIDENTIAL

CONFIDENTIAL NACA RM SL5.'DOi

• • ••t

;*..;

••o«

Ciu - —s d2V

Abbreviations:

lu

TT

vlng

upper tail

lower tall

fuselage

propeller

Subscripts:

F front

L left

R rlgbt

MODEL AND APPARATUS

The model used in this investigation was a 1/9-scale powered model of the Convalr XFY-1 vertically rising airplane. Pertinent geometric chju-acterlsties of the model are given in figure 2. The wing was built around a core made from l/2-lnch-tblck duralumin sheet and was built up to the proper contour with laminated mahogany. The fuselage and fins were constructed of laminated mahogany. All control sui-faces were made of solid duralimli. The wing and finb had nodified NACA 65-009 airfoil contours parallel to the model thrust line.

The propeller Diaaes. for which the geometric characteristic!} are given in figure 5, were constructed of heat-treated duralumin and were driven by a 50-horsepower water-cooled motor. ITie motor was equipped with a dual-rotating gear box. Power for the model motor »'as supplied by a 75-l'll ^-ati. motor-generator set, which is part of the eci-'lpmont of the Langl.*y Liability tunnel. Propeller cpeeds were measured by mans of a Stroboconn unit in conjunction with an alternator driven directly by the model rotor.

CONFTDENTIAL

fwm

NACA FM SL53D01 CONFIDEWTIAL

•• A two-strut support system was used to attach the model to a ••• • tix-campoaent balance system. Photographs of the model mounted on the

• ** ntruts are given as figure '+. All tests were made In the Langley sta- bility tunnel in. which yawing flow Is simulated by curving the air stream about a stationary model (ref. 2).

••••

••••

TESTS

All testa of this investigation were made at a dynamic pTeseun» of 16 pounds per square foot, which corresponds to a Nach number o? about 0.11 and a Reynolds number of 1.28 x 10" based on the wing mean aerodynamic chord of 1.73 feet. Moat of the teats were made with controls in the neutral position and with the front blades set at (ßo)f ■ 2')°. A few tests were made to determine effects of blade angle on the yawing sta- bility derivatives. In all cases the rear blades were set. at 1° less than the front blades. Effects of control deflections also were investigated.

The yawing stability derivatives of three basic model configurations were investigated, and these configurations were as follows:

Wing with fuselage and propellers W+F+P Wing with fuselage, upper tail, and piopeller W+F + Tu + P Complete model (wing with fuselage, upper tall, lower

tall, and propeller) W ■». r + Tu + IV + P

The characteristics of these configurations with propellers removec also were investigated.

The angle-of-at tack range for all tests was from about -k0 to 29°. Tests were made at values of rb/2V of 0, -0.0281, -O.O58I, and -C.OÖlV.

Power-on data were obtained for several thrust coefficients from 0 to 0.7- The thrust coefficient was held constant fci any particular ces* by holding the propeller spetd constant while varying the angle of attack. The scope of this investigation Is indicated In table I.

CORRECTIONS

Apiiroxlmate corrections for Jet-boundary effects were applied to the angle of ittack by the methods of reference 5- Blockage cornjctlons were determined and applied by the methods of reference h. Strut-tare correc- tions were determined experimentally and applied to all data.

CONFIDENTIAL

CONFIDENTIAL NACA RM 8L53D01

• •• • • • ••• • ••••

•••• ••••

PRESHITATIOH OF RESULTS

Ibe results of the Irrtetigatlon are presented In f' ires ^ to 9> The data, uodel configuration, and figure on which the data are shown axe indicated In table I for convenience in locating desired information. All moment data are referrod to the system of stability axes with the origin at the projection of the lU-percent wing mean aerodynamic chord on the plane of symetry.

COHCLUDING R2MARKS

An experimental investigation has been made in the Langley stability tunnel at low speed to determine the yawing stability derivatives of a l/9-scale powered model of the Convair XFY-1 vertically rising airplane. Effects of thrust coefficient wore investigated for the coo^lete model and for certain ccqpooents of the model. Effects cf control deflation and of propeller blade angle were investigated for the rcmplete model. Most of the tests were made through an angle-of-attack range from about

k0 to 29°, and the ttuuat-coef fie lent range was from 0 to 0.7.

In order to expedite distribution of these data, no analysis of the data has been prepared for this paper.

I Langley Aeronautical Laboratory',

Rational Advisory Comnlttee for Aeronautics, Langley Field, Va.

m Ji Queljc^/ Aeronautical Research Scientist

W. D. Wolhait Aeronautical Research SclentlBf.

H. S. Fletcher Aeronautical Research Scientist

Approved: Thomas A. Harris

Chief of ütability Research Division vr

CONFIDENTIAL

1MWWUJ11M]! IWIU

• •• • • • • •• • ••••

••••

»ACA m SL53D01 COIWIDEHTIAL

REFERENCES

••••

1. Queljo, M. J., Wolhart, W. D., and Fletcher, H. S.: Wind-Tunnel ***• Investigation at Low Speed of the Static Longitudinal and Lateral •••• Stability Character!at 1c8 of a l/9-Scale Powered Model of the

Convalr .CFY-l Vertically 'Using Airplane - TED NO. NACA IE 575- HACA IM 3L55B20, Bur. Aero., 1955-

2. Bird, John D., Jaquet, Byron M., and Cowan, John W.: Effect of Fujelage and Tail Surfaces on Lov-Speed Yawing ChrracteristicB of a Swept-Wing Model aa Determined in Curved-Flow Teat Section of the Langley Stability Tunnel. HACA TB dk&l, ITA- (Superaedes HACA m L8015.)

3. Silveraueln, Abe, and White, James A.: Wind-Tunnel Interference With Particular Reference To Off-Center Positions of tliC Wing and to the Downwash at the Tail. HACA Rep. 5^7, 193^.

k. Harriot, John C: Blockage CorrectionB for Three-Dimensional Closed- Throat Wind Tunnels, With ConBidenition of the Effects of Con^preos- Ibllity. HACA Rep. 995, 1950. (P-Jcrs-des HACA RM A7B28a.) I

CONFIDZNTLVL

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TABLE I

SUMMRT OF MOEEL CGHFIOURATIGHS TESTED,

TEST VARIABILES, AID DATA FKBaBTllU

Nodal eonf lguratlon Data presented Figure W + F + T U + T L + P (Po)p - S5°, 35°, 50°

Te' against propeller speed 5

V • F W • F + P, (fc>)p " 25°

Clr, Cnr against CL for various thrust coefficients 6(a)

V f F • Tu V + ? + Tu + P, (Pb), - 25°

°rr> clr> °nr CL

for various thrust coefficients 6(b)

W • F + Tu + Tj, W + F + T U + T L + P, (Po)p . 25°

°Ir> CZr, Cfcg. against Cj, for various thrust coefficients 6(c)

W • F • Tu + Tt W + F + T U + T L + P, . 35°

C*r, Cjr, Qnr against CL for various thrust coefficients 7

w • F • TJJ • !?£, V + F • Tu • ̂ • P, . 50°

°*r' c»r' ̂ r •«ain*t °L for various thrust coefficients 8

W + F + ^ + T L + P, (Po)p - 25°

V - 0 °rr> clr» •®a^n8t ° to* various control, deflections 9(a)

W+F+Tu+Tt+P, (PoJy - 25° Tc* - 0.2

°Iri Cjr, Cnr against a for various control deflections 9(h)

tf • F + Tu + TL • P, (po)y » 25° Tc* • O.fc

°*r' C*r» °nr a«aln*t a for various control deflections

9(c)

W • F + Tu • TL • P, (Po)p - 25° Tc' - 0.7

°*r» clr» ̂ r a«aln8t o for various control deflections 9(d)

CORFIHWTIAL

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CONFTDFI/riAL

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CCHFIEBNTIAL

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Figure 2.- Georaetrlc characteristics of model. All dlmen' .uns an; in inches.

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Finure U.- Concluded.

CONFIDENTIAL

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Figure 6.- Effect of thrust coefficient on the yawing stability derlva-tlves of various crqponents of a 1/9-scale powered model of the Convalr XFY-1 vertically rising alrplrne. (Po)F • 25°.

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FLf,uro ' - Continued.

CONFIDE OTI AI.

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Figure 6.- Concluded.

CONFIDENTIAL

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Figure 7.- Efft ;t of thrust coefficient on the yawing stability de.'lv.i. tlves of a j /9-6cale powered u:odel of the Convalr XFY-1 verticaLly rising ölrp]rjie. (ß0)p * Yf; configurations W + F + Tu + TL and W + F + Tu + TL + P.

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Figure 8.- Effect of thru-t coefficient on the yawing stability deriva- tives of a l/9-scale powered model of the Convalr XFY-1 vertically risl.ig aLrplnne. {ßo)f = '^O0; confitiurations W «- F + Tu + TL and W + F + Tu + rL + F.

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CONFIDBWriAL

flimi Services Technical Information Agency

Reproduced by

CLASSIFICATION CHANGED TO UNCLASSIFIED

B> «I!h.cU8rtfi«tloii Notlc. Wo. Ill «l-t«l 26 J^nu-rr 1937. Dall.tU U.t Hm. 120 ;

Dal. -Ht I L

OFFICE SECURITY ADVISOR

NOTICE: 'VKEN GOVERNMENT OR OTHER DRAWINGS, SPECIHCATIONS OR OTHER DATA ARE USED FOR ANY PURPOSE OTHER THAN IN CONNECTION WITH A DEFINITELY RELATED GOVERNME NT PROCUREMENT OPERATION, THE U. S. GOVERNMENT THEREBY INCURS NO RESPOf ABILITY, NOR ANY OBLIGATION WHATSOEVER; AND THE FACT THAT THE GOVERNMENT MAY HAVE FORMULATED, FURNISHED, OR IN ANY WAY SUPPLIED THE SAID DRAW^GS, SPECIFICATIONS, OR OTHER DATA IS NOT TO BE REGARDED BY IMPLICATIOr OR OTHERWISE AS IN ANT MANNER LICENSING THE HOLDER OR ANY OTHER PERSON OR ( ORPORATION, OR CONVEYING ANY RIGHTS OR PERMISSION TO MANUFACTURE USE OR 3EL : ANY PATENTED DIVENTION THAT MAY IN ANY WAY BE RELATED THERETO '

UNCLASSIFIED