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At least 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

Lateral and longitudinal aerodynamic stability and control parameters of the basic vortex flap research aircraft as determined from flight test data

The aerodynamics of the basic F-106B were determined at selected points in the flight envelope. The test aircraft and flight procedures were presented. Aircraft instrumentation and the data system were discussed. The parameter extraction procedure was presented along with a discussion of the test flight results. The results were used to predict the aircraft motions for maneuvers that were not used to determine the vehicle aerodynamics. The control inputs used to maneuver the aircraft to get data for the determination of the aerodynamic parameters were discussed in the flight test procedures. The results from the current flight tests were compared with the results from wind tunnel test of the basic F-106B.

Suit, W. T.↗
NASA NTRS1933

Wind tunnel research concerning lateral control devices, particularly at high angles of attack VII : Handley Page tip and full-span slots with ailerons and spoilers

Tests were made with ordinary ailerons and different sizes of spoilers on rectangular Clark Y wing models with Handley Page tip and full span slots. The tests showed the effect of the control devices on the general performance of the wings as well as on the lateral control and lateral stability characteristics.

Weick, Fred E↗
NASA NTRS1933

Wind tunnel research comparing lateral control devices, particularly at high angles of attack XI : various floating tip ailerons on both rectangular and tapered wings

Discussed here are a series of systematic tests being conducted to compare different lateral control devices with particular reference to their effectiveness at high angles of attack. The present tests were made with six different forms of floating tip ailerons of symmetrical section. The tests showed the effect of the various ailerons on the general performance characteristics of the wing, and on the lateral controllability and stability characteristics. In addition, the hinge moments were measured for the most interesting cases. The results are compared with those for a rectangular wing with ordinary ailerons and also with those for a rectangular wing having full-chord floating tip ailerons. Practically all the floating tip ailerons gave satisfactory rolling moments at all angles of attack and at the same time gave no adverse yawing moments of appreciable magnitude. The general performance characteristics with the floating tip ailerons, however, were relatively poor, especially the rate of climb. None of the floating tip ailerons entirely eliminated the auto rotational moments at angles of attack above the stall, but all of them gave lower moments than a plain wing. Some of the floating ailerons fluttered if given sufficiently large deflection, but this could have been eliminated by moving the hinge axis of the ailerons forward. Considering all points including hinge moments, the floating tip ailerons on the wing with 5:1 taper are probably the best of those which were tested.

Weick, Fred E↗
NASA NTRS1933

Wind-tunnel research comparing lateral control devices, particularly at high angles of attack II : slotted ailerons and frise ailerons

Three model wings, two with typical slotted ailerons and one with typical frise ailerons, have been tested as part of a general investigation on lateral control devices with particular reference to their effectiveness at high angles of attack, in the 7 by 10 foot wind tunnel of the National Advisory Committee for Aeronautics. Force tests, free-autorotation tests, and forced-rotation tests were made which show the effect of the various ailerons on the general performance of the wing, on the lateral controllability, and on the lateral stability, in general, rolling control at 20 degree angle of attack to plain ailerons of the same size. The adverse yawing moments obtained with the slotted and frise ailerons were, in most cases, slightly smaller than those obtained with plain ailerons of the same size and deflection. However, this improvement was small as compared to the improvement obtainable by the use of suitable differential movements with any of the ailerons, including the plain.

Weick, Fred E↗
NASA NTRS1935

Wind-tunnel research comparing lateral control devices, particularly at high angles of attack XII : upper-surface ailerons on wings with split flaps

This report covers the twelfth of a series of tests conducted to compare different lateral control devices with particular reference to their effectiveness at high angles of attack. The present wind tunnel tests were made with two sizes of upper-surface ailerons on rectangular Clark Y wing models equipped with full span split flaps. The tests showed the effect of the upper-surface ailerons and of the split flaps on the general performance characteristics of the wings, and on the lateral controllability and stability characteristics. The results are compared with those for plain wings with ordinary ailerons of similar sizes.

Weick, Fred E↗
NASA NTRS1961

Aerodynamic Characteristics of a Canard and an Outboard-Tail Airplane Model at High Subsonic Speeds

An investigation has been made in the Langley high-speed 7- by 10-foot tunnel through a range of Mach numbers from 0.60 to 0.95 of the static longitudinal and lateral stability and control characteristics of a canard airplane configuration and an outboard-tail configuration. The canard model had a twisted wing with approximately 67 deg of sweepback and an aspect ratio of 2.91 and was tested with three trapezoidal canard surfaces having ratios of exposed area to wing area of 0.032, 0.076, and 0.121. The canard model had a single body-mounted vertical tail. The outboard-tail model had its horizontal- and vertical-tail surfaces mounted on slender bodies attached to the wing tips and located to the rear and outboard of the 67 deg sweptback wing of aspect ratio 1.00. The data, which are presented with limited analysis, provide information at high subsonic speeds on these two types of high-speed airplanes which have previously been tested at supersonic speeds and reported in NACA RM L58BO7 and NACA RM L58E20.

Fournier, Paul G.↗
NASA NTRS1955

Flight Test of the Lateral Stability of a 0.133-Scale Model of the Convair XFY-1 Airplane with Windmilling Propellers at Mach Numbers from 0.70 to 1.12 (TED No. NACA DE 369)

A flight test of a rocket-propelled model of the Convair XFY-1 airplane was conducted to determine the lateral stability and control characteristics, The 0.133-scale model had windmilling propellers for this test, which covered a Mach number range of O.70 to 1.12. The center of gravity was located at 13.9 percent of the mean aerodynamic chord. The methods of analysis included both a solution by vector diagrams and simple one- and two-degree-of-freedom methods. The model was both statically and dynamically stable throughout the speed range of the testa The roll damping was good, and the slope of the side-force curve varied little with speed. The rudder was effective throughout the test speed range, although it was reduced to about 43 percent of its subsonic value at supersonic speeds.

Hollinger, James A.↗
NASA NTRS1991

Dynamic stall effects and applications to high performance aircraft

Recent research conducted at the NASA Langley Research Center on the effects of large amplitude pitching motions on the aerodynamic characteristics of modern fighter aircraft configurations is highlighted. Wind tunnel tests were conducted on simple flat-plate wings to gain understanding of the complex flow phenomena during unsteady motions at high angles of attack. Studies then progressed to a representative modern fighter configuration. Using a computer controlled dynamic apparatus, tests were conducted to investigate effects of pitch rate and motion time history and to determine the persistence of unsteady effects. Data were also obtained in sideslip and with control surface deflections to investigate dynamic effects on lateral stability and available control power. Force and moment data were obtained using a 6-component internal strain-gage balance. To aid in the interpretation of the results, flow visualization using a laser light-sheet system was also obtained. Results of these tests are discussed, along with their implications on the maneuverability of future advanced airplanes designed to operate in the highly dynamic, high angle-of-attack environment.

Brandon, Jay M.↗
NASA NTRS1961

Investigation of Longitudinal and Lateral Stability Characteristics of a Six-Propeller Deflected-Slipstream VTOL Model with Boundary-Layer Control Including Effects of Ground Proximity

An investigation of the longitudinal and lateral stability and control and Performance characteristics of a six-propeller deflected- slipstream vertical-take-off-and-landing (VTOL) model in the transition speed range was conducted in the 17-foot test section of the Langley 300-MPH 7- by 10-foot tunnel. A complete analysis of the data was not conducted. A modest amount of blowing boundary-layer control was necessary to achieve transition without wing stall.

Grunwald, Kalman J.↗
NASA NTRS1944

Experimental Verification of the Rudder-Free Stability Theory for an Airplane Model Equipped with Rudders Having Negative Floating Tendency and Negligible Friction

An investigation has been made in the Langley free-flight tunnel to obtain an experimental verification of the theoretical rudder-free stability characteristics of an airplane model equipped with conventional rudders having negative floating tendencies and negligible friction. The model used in the tests was equipped with a conventional single vertical tail having rudder area 40 percent of the vertical tail area. The model was tested both in free flight and mounted on a strut that allowed freedom only in yaw. Tests were made with three different amounts of rudder aerodynamic balance and with various values of mass, moment of inertia, and center-of-gravity location of the rudder. Most of the stability derivatives required for the theoretical calculations were determined from forced and free-oscillation tests of the particular model tested. The theoretical analysis showed that the rudder-free motions of an airplane consist largely of two oscillatory modes - a long-period oscillation somewhat similar to the normal rudder-fixed oscillation and a short-period oscillation introduced only when the rudder is set free. It was found possible in the tests to create lateral instability of the rudder-free short-period mode by large values of rudder mass parameters even though the rudder-fixed condition was highly stable. The results of the tests and calculation indicated that for most present-day airplanes having rudders of negative floating tendency, the rudder-free stability characteristics may be examined by simply considering the dynamic lateral stability using the value of the directional-stability parameter Cn(sub p) for the rudder-free condition in the conventional controls-fixed lateral-stability equations. For very large airplanes having relatively high values of the rudder mass parameters with respect to the rudder aerodynamic parameters, however, analysis of the rudder-free stability should be made with the complete equations of motion. Good agreement between calculated and measured rudder-free stability characteristics was obtained by use of the general rudder-free stability theory, in which four degrees of lateral freedom are considered. When this assumption is made that the rolling motions alone or the lateral and rolling motions may be neglected in the calculations of rudder-free stability, it is possible to predict satisfactorily the characteristics of the long-period (Dutch roll type) rudder-free oscillation for airplanes only when the effective-dihedral angle is small. With these simplifying assumptions, however, satisfactory prediction of the short-period oscillation may be obtained for any dihedral. Further simplification of the theory based on the assumption that the rudder moment of inertia might be disregarded was found to be invalid because this assumption made it impossible to calculate the characteristics of the short-period oscillations.

STABILITY- FAIRCHILD R2K-1↗
NASA NTRS1999

High Reynolds Number Effects on HSCT Stability and Control Characteristics

Two wind tunnel tests during 1995 in the National Transonic Facility (NTF 070 and 073) served to define Reynolds number effects on longitudinal and lateral-directional stability and control. Testing was completed at both high lift and transonic conditions. The effect of Reynolds number on the total airplane configuration, horizontal and vertical tail effectiveness, forebody chine performance, rudder control and model aeroelastics was investigated. This paper will present pertinent stability and control results from these two test entries. Note that while model aeroelastic effects are examined in this presentation, no corrections for these effects have been made to the data.

Elzey, Michael B.↗