Engineering PapersSearch

SEARCH · Engineering Papers

Results for “sideslip”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3

Determination of angles of attack and sideslip from radar data and a roll-stabilized platform

Equations for angles of attack and sideslip relative to both a rolling and nonrolling body axis system are derived for a flight vehicle for which radar and gyroscopic attitude data are available. The method is limited to application where a flat, nonrotating earth may be assumed. The gyro measures attitude relative to an inertial reference in an Euler angle sequence. In particular, a pitch, yaw, and roll sequence is used as an example in the derivation. Sample calculations based on flight data are presented to illustrate the method. Results obtained with the present gyro method are compared with another technique that uses onboard camera data.

Preisser, J. S.

Flight-determined lag of angle-of-attack and angle-of-sideslip sensors in the YF-12A airplane from analysis of dynamic maneuvers

Magnitudes of lags in the pneumatic angle-of-attack and angle-of-sideslip sensor systems of the YF-12A airplane were determined for a variety of flight conditions by analyzing stability and control data. The three analysis techniques used are described. An apparent trend with Mach number for measurements from both of the differential-pressure sensors showed that the lag ranged from approximately 0.15 second at subsonic speed to 0.4 second at Mach 3. Because Mach number was closely related to altitude for the available flight data, the individual effects of Mach number and altitude on the lag could not be separated clearly. However, the results indicated the influence of factors other than simple pneumatic lag.

Gilyard, G. B.

Low speed aerodynamic characteristics of an 0.075-scale F-15 airplane model at high angles of attack and sideslip

An 0.075 scale model representative of the F-15 airplane was tested in the Ames 12 foot pressure wind tunnel at a Mach number of 0.16 to determine static longitudinal and lateral directional characteristics at spin attitudes for Reynolds numbers from 1.48 to 16.4 million per meter (0.45 to 5.0 million per foot). Angles of attack ranged from 0 to +90 deg and from -40 deg to -80 deg while angles of sideslip were varied from -20 deg to +30 deg. Data were obtained for nacelle inlet ramp angles of 0 to 11 deg with the left and right stabilators deflected 0, -25 deg, and differentially 5 deg and -5 deg. The normal pointed nose and two alternate nose shapes were also tested along with several configurations of external stores. Analysis of the results indicate that at higher Reynolds numbers there is a slightly greater tendency to spin inverted than at lower Reynolds numbers. Use of a hemispherical nose in place of the normal pointed nose provided an over correction in simulating yawing moment effects at high Reynolds numbers.

Petroff, D. N.

Subsonic longitudinal and lateral directional static stability characteristics of a variable sweep fighter configuration employing various control surface deflections at angles of attack of 0 deg to 50 deg and large sideslip angles

A variable sweep fighter configuration with the wing in the 22 deg sweep position having leading edge slats and trailing edge flaps on the outboard panels was tested at a Mach number of 0.15 in the Langley 7- by 10-foot high speed tunnel. The angle of attack range was 0 deg to 50 deg and the sideslip angle range was -20 deg to 20 deg. Pitch, roll, and yaw control effectiveness were studied as well as the effects of spoilers. The data are presented without analysis.

Jarrett K Huffman

Surface pressure data on a series of conical forebodies at Mach numbers from 1.70 to 4.50 and combined angles of attack and sideslip

Tabulated surface pressure data for a series of forebodies which have analytically defined cross sections and are based on a 20 degs half-angle cone are presented without analysis. Five of the cross sections were ellipses having axis ratios of 3/1, 2/1, 1/1, 1/2, and 1/3. The sixth cross section was defined by a curve having a single lobe. The data generally cover angles of attack from -5 degs to 20 degs at angles of sideslip from 0 degs to 5 degs for Mach numbers of 1.70, 2.50, 3.95, and 4.50 at a constant Reynolds number.

Townsend, J. C.

Surface pressure data on a series of analytic forebodies at Mach numbers from 1.70 to 4.50 and combined angles of attack and sideslip

Tabulated surface pressure data for a series of four forebodies which have analytically defined cross sections and which are based on a parabolic arc profile having a 20 deg half angle at the nose are presented without analysis. The first forebody has a circular cross section, and the second has a cross section which is an ellipse with an axis ratio of 2/1. The third has a cross section defined by a lobed analytic curve. The fourth forebody has cross sections which develop smoothly from circular at the pointed nose through the lobed analytic curve and back to circular at the aft end. The data generally cover angles of attack from -5 deg to 20 deg at angles of sideslip from 0 deg to 5 deg for Mach numbers of 1.70, 2.50, 3.95, and 4.50 at a constant Reynolds number.

Townsend, J. C.

Evaluation of a flow direction probe and a pitot-static probe on the F-14 airplane at high angles of attack and sideslip

The measurement performance of a hemispherical flow-angularity probe and a fuselage-mounted pitot-static probe was evaluated at high flow angles as part of a test program on an F-14 airplane. These evaluations were performed using a calibrated pitot-static noseboom equipped with vanes for reference flow direction measurements, and another probe incorporating vanes but mounted on a pod under the fuselage nose. Data are presented for angles of attack up to 63, angles of sideslip from -22 deg to 22 deg, and for Mach numbers from approximately 0.3 to 1.3. During maneuvering flight, the hemispherical flow-angularity probe exhibited flow angle errors that exceeded 2 deg. Pressure measurements with the pitot-static probe resulted in very inaccurate data above a Mach number of 0.87 and exhibited large sensitivities with flow angle.

Larson, T. J.

PAN AIR modeling studies. II - Sideslip option, network gaps, three-dimensional forebody flow, and thick-trailing-edge representation

PAN AIR is a computer program that calculates linear potential flow about arbitrary configurations at both subsonic and supersonic Mach numbers. This paper is a follow-on of another paper entitled 'PAN AIR Modeling Studies', in which several studies were presented that exhibited PAN AIR's versatility for modeling diverse configurations. Results from four modeling studies of interest in modeling realistic aircraft shapes are presented. The topics addressed are (1) half-geometry option in sideslip, (2) network gaps, (3) three-dimensional forebody flows, and (4) trailing-edge representation.

Strande, S.

Computer programs for calculation of sting pitch and roll angles required to obtain angles of attack and sideslip on wind tunnel models

Two programs have been developed to calculate the pitch and roll angles of a wind-tunnel sting drive system that will position a model at the desired angle of attack and and angle of sideslip in the wind tunnel. These programs account for the effects of sting offset angles, sting bending angles and wind-tunnel stream flow angles. In addition, the second program incorporates inputs from on-board accelerometers that measure model pitch and roll with respect to gravity. The programs are presented in the report and a description of the numerical operation of the programs with a definition of the variables used in the programs is given.

Peterson, John B., Jr.

Numerical study of vortical flow over a sideslipping delta wing

The three-dimensional vortical viscous flow past a sideslipping delta wing at a high angle of attack is numerically investigated. A computational method for calculating low-speed viscous flowfields is developed. The time-iterative method uses an implicit upwind-relaxation finite-difference algorithm with a nonsingular eigensystem to solve the preconditioned, three-dimensional, incompressible Navier-Stokes equations in curvilinear coordinates. An algebraic turbulence model is implemented to account for the eddy viscosity. The technique of local time stepping is incorporated to accelerate the rate of convergence to a steady-state solution. Computed results are compared with experimental data.

Hsu, C.-H.

Computer programs for the calculation of dual sting pitch and roll angles required for an articulated sting to obtain angles of attack and sideslip on wind-tunnel models

Two programs were developed to calculate the pitch and roll position of the conventional sting drive and the pitch of a high angle articulated sting to position a wind tunnel model at the desired angle of attack and sideslip and position the model as near as possible to the centerline of the tunnel. These programs account for the effects of sting offset angles, sting bending angles, and wind-tunnel stream flow angles. In addition, the second program incorporates inputs form on-board accelerometers that measure model pitch and roll with respect to gravity. The programs are presented and a description of the numerical operation of the programs with a definition of the variables used in the programs is given.

Peterson, John B., Jr.

A low-speed experimental study of the directional characteristics of a sharp-nosed fuselage through a large angle-of-attack range at zero angle of sideslip

Static yawing moments and some instantaneous yawing moments are presented through a range of angle of attack at zero sideslip angle for a plain fuselage model having a sharp conical nose and for the fuselage with several nose modifications, one of which consisted of a ring located at different stations along the nose. Some circumferential pressure measurements at one station on the body at several angles of attack are also presented.

PROTUBERANCES-BODIES

A Comparison of the Experimental and Theoretical Loading over Triangular Wings in Sideslip at Supersonic Speeds

The results of an experimental investigation of the load distribution over two triangular wings in sideslip at Mach numbers from 1.20 to 1.79 are presented and compared with theory. The two wings tested have identical plan form, 45 degrees sweepback of the leading edge, and an aspect ratio of 4.0. One model was composed of round-nose airfoil sections and the other of sharp-nose, biconvex sections. For both wings the maximum thickness of streamwise sections was 6 percent and was located at the 30-percent chord.

DIHEDRAL - COMPLETE WING

Aerodynamic Characteristics of Missile Configurations with Wings of Low Aspect Ratio for Various Combinations of Forebodies, Afterbodies, and Nose Shapes for Combined Angles of Attack and Sideslip at a Mach Number of 2.01

An investigation has been made in the Langley 4-by-4-foot supersonic pressure tunnel to determine the aerodynamic characteristics of a series of missile configurations having low-aspect-ratio wings at a Mach number of 2.01. The effects of wing plan form and size, length-diameter ratio, forebody and afterbody length, boattailed and flared afterbodies, and component force and moment data are presented for combined angles of attack and sideslip to about 28 degrees. No analysis of the data was made in this report.

Robinson, Ross B

Effect of Horizontal-Tail Span and Vertical Location on the Aerodynamic Characteristics of an Unswept Tail Assembly in Sideslip

An investigation has been conducted in the Langley stability tunnel on a vertical-tail model with a stub fuselage in combination with various horizontal tails to determine the effect of horizontal-tail span and vertical location of the horizontal tail relative to the vertical tail on the aerodynamic characteristics of an unswept tail assembly in sideslip. The results of the investigation indicated that the induced loading carried by the horizontal tail produced a rolling moment about the point of attachment to the vertical tail which was strongly influenced by horizontal-tail span and vertical locations. The greatest effect of horizontal-tail span on the rolling-moment derivative of the complete tail assembly was obtained for horizontal-tail locations near the top of the vertical tail. Span loadings which were reduced to the static-stability derivatives were calculated for each configuration tested by applying the well-known finite-step method used for wings to the intersecting surfaces of the vertical and horizontal tails. The finite-step method provides a simple and effective means of investigating the span loadings of intersecting surfaces.

Riley, Donald R

Experimental investigation of the forces and moments due to sideslip of a series of triangular vertical and horizontal tail combinations at Mach numbers

An experimental investigation was made at Mach numbers of 1.62, 1.93, and 2.41 of a series of tail combinations consisting of triangular vertical tail attached symmetrically to a triangular horizontal tail to determine the lateral force, yawing moment, and rolling moment due to sideslip. The apex angles of both the vertical- and horizontal-tail surfaces were varied systematically in order to obtain results for an appreciable range of operating conditions. The results of the investigation indicated that, for tails having subsonic leading edges and supersonic trailing edges, the lateral-force derivative and the yawing-moment derivative were predicted satisfactorily by the method presented in NACA TN 3071 except when the leading edges approach a sonic condition. The theoretical rolling-moment derivative was in fair agreement with the experimental derivative. For the limited tests in which both the leading and trailing edges were supersonic, the prediction of the lateral-force derivative and the yawing-moment derivative obtained from NACA TN 2412 was in good agreement with the experimental derivatives, whereas the prediction of the rolling-moment derivative was fair.

Coletti, Donald E

The dangerous sideslip of a stalled airplane and its prevention

This investigation covers only that phase of airplane accidents which are the result of sideslip. We examine the circumstances under which this occurs, study the behavior of present-day airplane types (monoplane, conventional and staggered biplane) therein and endeavor to find a solution whereby this danger may be avoided.

Fuchs, Richard

Low-Speed Investigation of the Effects of Frequency and Amplitude of Oscillation in Sideslip on the Lateral Stability Derivatives of a 60 deg Delta Wing, a 45 deg Sweptback Wing and an Unswept Wing

A low-speed investigation has been conducted in the Langley stability tunnel to study the effects of frequency and amplitude of sideslipping motion on the lateral stability derivatives of a 60 deg. delta wing, a 45 deg. sweptback wing, and an unswept wing. The investigation was made for values of the reduced-frequency parameter of 0.066 and 0.218 and for a range of amplitudes from +/- 2 to +/- 6 deg. The results of the investigation indicated that increasing the frequency of the oscillation generally produced an appreciable change in magnitude of the lateral oscillatory stability derivatives in the higher angle-of-attack range. This effect was greatest for the 60 deg. delta wing and smallest for the unswept wing and generally resulted in a more linear variation of these derivatives with angle of attack. For the relatively high frequency at which the amplitude was varied, there appeared to be little effect on the measured derivatives as a result of the change in amplitude of the oscillation.

Lichtenstein, Jacob H.