1、 :NASA TECHNICAL NOTEcO|ZZCOPYNASA TN D-4983FULL-SCALE WIND-TUNNEL INVESTIGATIONOF STATIC LONGITUDINAL ANDLATERAL CHARACTERISTICS OFA LIGHT TWIN-ENGINE AIRPLANEby Marvin P. Fink and Delma C. Freeman, Jr.Langley Research CenterLangley Station, Hampton, Va.NATIONALAERONAUTICSAND SPACEADMINISTRATION WA
2、SHINGTON,D. C. JANUARY1969Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NASA TN D-4983FULL-SCALE WIND-TUNNEL INVESTIGATION OFSTATIC LONGITUDINAL AND L
3、ATERAL CHARACTERISTICS OF ALIGHT TWIN-ENGINE AIRPLANEBy Marvin P. Fink and Delma C. Freeman, Jr.Langley Research CenterLangley Station, Hampton, Va.NATIONAL AERONAUTICS AND SPACE ADMINISTRATIONFor sale by the Clearinghouse for Federal Scientific and Technical InformationSpringfield, Virginia 22151 -
4、 CFSTI price $3.00Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-FULL-SCALE WIND-TUNNEL INVESTIGATION OFSTATIC LONGITUDINAL AND LATERAL CHARACTERISTICS
5、 OF ALIGHT TWIN-ENGINE AIRPLANEBy Marvin P. Fink and Delma C. Freeman, Jr.Langley Research CenterSUMMARYAn investigation has been conducted in the Langley full-scale tunnel to determine thestatic longitudinal and lateral stability and control characteristics of a full-scale lighttwin-engine airplane
6、. Hinge moments were also measured for all control and flap sur-faces during the investigation. The investigation was made over an angle-of-attack rangeof -4 to 18 at various angles of sideslip between +8 for various power and flap settings.The thrust coefficients were 0, 0.20, and 0.44, which corre
7、spond to either a low-power ora high-speed condition, to a climb condition, and to a take-off or a wave-off condition,respectively, for an airplane having installed horsepower of 200 per engine.The investigation showed that, in general, the airplane has stick-fixed longitudinalstability through the
8、stall, but stick-fixed instability could be encountered at some liftcoefficients with rearward center-of-gravity location, particularly at a thrust coefficientof 0.44 and flaps deflected 27 o. The airplane has stick-free stability through the stall,however, for all power, flap, and center-of-gravity
9、 conditions investigated. At angles ofattack below the stall, the airplane is directionally stable, has positive effective dihedral,and the variation of the lateral coefficients is fairly linear. At angles of attack above thestall, the airplane is directionally stable, and has positive effective dih
10、edral for all condi-tions except at a thrust coefficient of 0; however, rolling and yawing moments greater thanthose produced by full opposite control occur at zero sideslip, particularly at a thrustcoefficient of 0.20, because of asymmetrical wing stall. Aileron and rudder effectivenessis maintaine
11、d through the stall.INTRODUCTIONFor the past several years the NASA Flight Research Center has been conducting aprogram to evaluate the flying qualities of a number of general-aviation aircraft. Theresults of these investigations have been reported in reference 1. As a part of the con-tinuing invest
12、igation, one of the airplanes investigated in reference 1, a light twin-engineconfiguration, has been tested in the Langley full-scale tunnel. The investigation wasProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-madeto determine the static longitudin
13、al and lateral stability and control characteristicswith various power (up to 200 horsepower per engine) and flap settings over a range ofangles of attack from -4 to 18 and over a range of sideslip angles of +8 . All of the testsexcept those at a thrust coefficient of 0.44 were made at a tunnel spee
14、d of about 93 feet persecond (28.35 meters per second) giving a Reynolds number of approximately 2.96 x 106based on a mean aerodynamic chord of 5 feet (1.52 meters). Tests at 0.44 thrust coeffi-cient were made at a tunnel speed of about 63 feet per second (19.2 meters per second).SYMBOLSFigure 1 sho
15、ws the stability-axis system used in the presentation of the data and thepositive direction of forces, moments, and angles. The data are computed about themoment center (see fig. 2) which is at airplane longitudinal station 85 or 10.0 percent ofthe mean aerodynamic chord. All areas used in determini
16、ng hinge-moment coefficientsare defined as the area back of the hinge line.Measurements for this investigation were made in the U.S. Customary System ofUnits. Equivalent values are indicated herein in the International System (SI) in the inter-est of promoting the use of this system in NASA reports.
17、 Factors relating the two sys-tems of units used in this paper may be found in the appendix.b wing span, 35.98 feet (10.97 meters)DragC D drag coefficient, qSCh,aCh,fCh,rCh,tCh,tabCL2aileron hinge-moment coefficient, Hinge momentqSaEaflap hinge-moment coefficient, Hinge momentqSf_frudder hinge-momen
18、t coefficient, Hinge momentqSr_rhorizontal-tail hinge-moment coefficient, Hinge momentqStEthorizontal-tail tab hinge-moment coefficient, Hinge momentqStab_tabaileron hinge-moment parameter, aC h , per degree05,alift coefficient, LiftqSProvided by IHSNot for ResaleNo reproduction or networking permit
19、ted without license from IHS-,-,-/ : ii/: i-;? _ , _ :i!_i , iCL_C 1ClfiC/5,aCmCms,tC nCnl3Cns,rCylift-curve sloperolling-moment coefficient, Rolling momentqSblateral stability parameter; effective dihedral parameter,aileron effectiveness parameter 8CI85,a per degreepitching-moment coefficient, Pitc
20、hing momentqS_Cm per degreehorizontal-tail effectiveness parameter, _6,tyawing-moment coefficient, Yawing momentqSbdirectional stability parameter, aC na_ per degreerudder effectiveness parameter, 8Cn-, per degree_6,rside-force coefficient, Side forceqSmean aerodynamic chord, 5 feet (1.53 meters)aC
21、18_ per degreeaileron mean chord, 1.0 foot (0.30 meter)flap mean chord, 1.16 feet (0.35 meter)rudder mean chord, 1.2 feet (0.37 meter)tail mean chord, 2.7 feet (0.82 meter)_tabDtab mean chord, 0.5 foot (0.15 meter)propeller diameter, 6.0 feet (1.83 meters)yawing-moment parameter, foot-pounds per deg
22、ree (newton-meters perdegree)Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-nqSS aSfSrstStabTWbVXOl5a5f6 r8t6tabrotational speed, revolutions per secondfree-stream dynamic pressure, pounds force/foot2wing area, 178 feet 2 (16.50 meters2)area of one
23、aileron, 5.8 feet2 (0.548 meter2)area of one flap, 7.65 feet2 (0.71 meter2)area of rudder, 5.2 feet 2 (0.482 meter2)area of horizontal tail, 19.5 feet2 (1.81 meters2)area of tail tab, 5.0 feet2 (0.464 meter2)(newtons/m ete r 2)effective thrust, Dragpropellers removed - Dragpropellers operatingthrust
24、 coefficient, TqSfree-stream velocity, feet/second (meters/second)longitudinal axisangle of attack of fuselage reference line, degreesangle of sideslip, positive when nose is to left, degreestotal aileron deflection, positive when right aileron is down, 5aL - BaR ,degreesflap deflection, positive wh
25、en trailing edge is down, degreesrudder deflection, positive when trailing edge is left, degreeshorizontal-tail deflection, positive when trailing edge is down, degreeshorizontal-tail tab deflection, degreesaverage downwash angle, degreesProvided by IHSNot for ResaleNo reproduction or networking per
26、mitted without license from IHS-,-,-Subscripts:L leftmax maximumR rightThe gearing constants at zero control deflection for the three controls are as follows:Aileron . 0.80 radian/foot (0.24 radian/meter)Elevator 0.42 radian/foot (0.13 radian/meter)Rudder . 0.93 radian/foot (0.25 radian/meter)AIRP L
27、ANEThe airplane tested was a light twin-engine low-wing monoplane. Figure 2 gives theprincipal dimensions and figure 3 shows the airplane mounted in the tunnel test section.The airplane had a wing span of 35.98 feet (10.97 m), a wing area of 178 feet2 (16.50 m2),an aspect ratio of 7.3, and a mean ae
28、rodynamic chord of 5 feet (1.53 m) based on projec-tion of the outboard leading edge of the wing through the fuselage. The wing airfoil sectionwas a modified NACA 642A215 airfoil with the trailing-edge cusp faired out. The wingleading edge was modified as shown in figure 2(b) for some tests. The win
29、g had 5 ofdihedral and no twist and was at 2 positive incidence with respect to the fuselage refer-ence line. The thrust axes were parallel to the reference line. The airplane had thestandard three-control system. The horizontal tail was of the all-movable type with acontrol deflection range of 4 to
30、 -14 . The tail had a trailing-edge tab which moved inthe same direction as the tail with a deflection ratio (tab deflection to tail deflection) of1.5. The control deflection range on each aileron was from 14 to -18 . The ruddercontrol deflection range was limited to +20 because of restrictions impo
31、sed by remotelycontrolled actuators that were installed for these tests. The airplane normally wouldhave +27 of rudder deflection.TESTSThe tests were made to determine the static longitudinal and lateral stability andcontrol characteristics of the airplane over a wide range of flight conditions. Hin
32、gemoments were also measured for all control and flap surfaces during the investigation.The airplane was tested over an angle-of-attack range of -4 to 18 , over a sideslip rangeof +8 for the clean condition (Sf = 0; gear up), and for flap deflections of 15 and 27 Provided by IHSNot for ResaleNo repr
33、oduction or networking permitted without license from IHS-,-,-with the gear down. A range of tail incidenceanglesfrom 4 to -14 was investigated atzero sideslip, andthe aileron andrudder effectiveness was measuredover the sidesliprange. Althoughthe airplane has engineswith 160-rated horsepower, power
34、 conditions ofup to 200horsepower were simulatedwith thrust coefficients of 0, 0.20, and 0.44repre-sentingflight conditions of low power or high speed,a climb at about 90-percent power,anda climb at full power as in take-off or wave-off conditions, respectively. The climbandtake-off thrust coefficie
35、nts with the 160-horsepowerenginesare 0.14 and0.35, respec-tively. Severaltests were madewith asymmetric power to simulate anengine-out con-dition for either enginewith the inoperative enginein a windmilling condition andafeathered-propeller condition. The running enginehadfull power (Tc = 0.44) for
36、 theasymmetric power test. The propeller blade angle and consequently the advance ratiofor each thrust coefficient were set at fixed values which were representative of thosefor flight conditions at which the particular value of thrust coefficient could be achieved.The values of V/nD were 0.78, 0.64
37、, and 0.44 for values of T_ of 0, 0.20, and 0.44,respectively.PRESENTATION OF DATAThe data from these tests have been corrected for airstream misalinement, buoyancyeffects, and mounting strut tares. Wind-tunnel jet-boundary corrections derived accordingto references 2 and 3 have been applied.The dat
38、a are presented in the following figures:FigureLongitudinal characteristics with propellers removed 4Longitudinal characteristics with windmilling propellers and zero thrust 5Longitudinal characteristics with power and flap deflections 6 to 8Longitudinal characteristics with horizontal-tail tab fixe
39、d (Stab = 0 o) 9Longitudinal characteristics with horizontal tail removed 10Longitudinal characteristics with asymmetric power . 11Longitudinal characteristics with leading-edge radius increased 12Variation of pitching-moment coefficient with tail deflection 13Lateral characteristics with propellers
40、 removed 14Lateral characteristics with windmilling propellers . 15Lateral characteristics with power and flap deflections 16 to 18Lateral characteristics with vertical tail removed 19 and 20Lateral characteristics with asymmetric power 21 to 24Lateral characteristics with aileron deflection. 5f = 0
41、 25 to 27!i:Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-FigureLateral characteristics with aileron deflection 5f = 27 . 28 to 30Lateral characteristics with rudder deflection 5f = 0 31 to 33Lateral characteristics with rudder deflection 5f = 27 .
42、 34 to 36Lateral characteristics with rudder deflection for asymmetric power5f = 0 . 37 to 39Lateral characteristics with rudder deflection for asymmetric power_f = 27 . 40 to 44Lateral stability characteristics with propellers removed and flaps deflected . . . 45Lateral stability characteristics wi
43、th windmilling propellers, zero thrust,and propellers removed * * “ “ 46Lateral stability characteristics with power and flap deflections 47Directional stability characteristics with power and flap deflections 48Lateral and directional stability characteristics for asymmetric power 49Aileron effecti
44、veness . 50Rudder effectiveness . 51 and 52Horizontal-tail hinge-moment coefficients . 53 to: 56Horizontal-tail tab hinge-moment coefficient 57Rudder hinge-moment coefficients 58 and 59Aileron hinge-moment coefficients . 60 to 62Total aileron hinge-moment coefficients for full right control . 63Flap
45、 hinge-moment coefficients 64 to 66Effect of power on longitudinal characteristics . . . . . . . . . . . . . . . . . . . 67Effect of power on lift-curve slope and maximum lift coefficient 68Effect of power on longitudinal stability 69 Stick-free pitching-moment characteristics . 70Effect of power on
46、 horizontal-tail control power . 71 and 72Downwash at tail 73Effect of asymmetric power on longitudinal characteristics 74Effective dihedral characteristics 75Directional stability characteristics . 76Yawing-moment characteristics . 77Aileron and rudder effectiveness . 78Comparison of rolling- and y
47、awing-moment coefficients for various powerconditions 79Lateral characteristics with leading-edge radius increase . . . . . . . . . . . . . 80Control capability . 81 and 82Stability characteristics with asymmetric power . . . . . . . . . . . . . . . . . . 83Rudder effectiveness with asymmetric power 84 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-il, ,!RESULTS AND DISCUSSIONThe basic data obtained during the wind-tunnel investigation are presented in fig-ures 4 to 66 without analys
