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Results for “STABILITY & CONTROL, LONGITUDINAL - STATIC”

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.

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At least 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
NASA NTRS1982

Longitudinal control effectiveness and entry dynamics of a single-stage-to-orbit vehicle

The classical theory of flight dynamics for airplane longitudinal stability and control analysis was extended to the case of a hypervelocity reentry vehicle. This includes the elements inherent in supersonic and hypersonic flight such as the influence of the Mach number on aerodynamic characteristics, and the effect of the reaction control system and aerodynamic controls on the trim condition through a wide range of speed. Phugoid motion and angle of attack oscillation for typical cases of cruising flight, ballistic entry, and glide entry are investigated. In each case, closed form solutions for the variations in altitude, flight path angle, speed and angle of attack are obtained. The solutions explicitly display the influence of different regions design parameters and trajectory variables on the stability of the motion.

Vinh, N. X.↗
NASA NTRS1976

Application of optimal input synthesis to aircraft parameter identification

The Frequency Domain Input Synthesis procedure is used in identifying the stability and control derivatives of an aircraft. By using a frequency-domain approach, one can handle criteria that are not easily handled by the time-domain approaches. Numerical results are presented for optimal elevator deflections to estimate the longitudinal stability and control derivatives subject to root-mean square constraints on the input. The applicability of the steady state optimal inputs to finite duration flight testing is investigated. The steady state approximation of frequency-domain synthesis is good for data lengths greater than two time cycles for the short period mode of the aircraft longitudinal motions. Phase relationships between different frequency components become important for shorter data lengths. The frequency domain inputs are shown to be much better than the conventional doublet inputs.

Gupta, N. K.↗
NASA NTRS1974

Results of investigations (OA20C) on an 0.015-scale configuration 140A/B space shuttle vehicle orbiter model (49-0) in the NASA/Langley Research Center Unitary Plan Wind Tunnel

Data obtained from the wind tunnel tests of a scale model of the space shuttle orbiter configuration 140 A/B are presented. The test was conducted at Mach numbers of 2.5, 3.9, and 4.6 with Reynolds numbers from 1.25 million per foot to 5.0 million per foot. Various control surface settings were used ranging from an angle of attack range from minus 4 to plus 42 degrees at zero angle of yaw. Longitudinal stability and control characteristics of the space shuttle configuration were analyzed.

Nichols, M. E.↗
NASA NTRS1995

Subsonic-to-Hypersonic Aerodynamic Characteristics for a Winged, Circular-Body, Single-Stage-to-Orbit Spacecraft Configuration

Experimental aerodynamic characteristics were obtained for a generic, winged, circular-body, single-stage-to-orbit spacecraft configuration. The baseline configuration was longitudinally stable and trimmable at almost all Mach numbers from 0.15 to 10.0--with the exception occurring at low supersonic speeds. Landing speed and subsonic-to-hypersonic longitudinal stability and control appear to be within design guidelines. Lateral-directional instabilities found over the entire speed range, however, create a problem area for this configuration. Longitudinal aerodynamic predictions made utilizing the Aerodynamic Preliminary Analysis System (APAS) were in qualitative, often quantitative agreement with experimental values.

Phillips, W. P.↗
NASA NTRS1958

Aerodynamic Characteristics in Sideslip of a Large-Scale 49 deg Sweptback Wing-Body-Tail Configuration with Blowing Applied Over the Flaps and Wing Leading Edge

An investigation has been conducted in the Langley full-scale tunnel to determine the aerodynamic characteristics in sideslip of a large-scale 490 sweptback wing-body-tail configuration having wing leading- edge and flap-blowing boundary-layer control. The wing and tails had an aspect ratio of 3.5, a taper ratio of 0.3, and NACA 65AO06 airfoil sections parallel to the plane of symmetry. The tests were conducted over a range of angles of attack of about -5 deg to 28 deg for sideslip angles of 0 deg, -5.06 deg, -10.15 deg, and -15.18 deg. Lateral and longitudinal stability and control characteristics were obtained for6a minimized blowing rate. The Reynolds number of the tests was 5.2 x 10(exp 6), corresponding to a Mach number of 0.08. The results of the investigation showed that sideslip to angles of about -15 deg did not require, from a consideration of the longitudinal characteristics, blowing rates over the wing leading edge or flap greater than that established as minimum at zero sideslip. The optimum configuration was laterally and directionally stable through the complete lift-coefficient range including the stall; however, maximum lift for sideslip angles greater than about 50 was seriously limited by a deficiency of lateral control. Blowing over the leading edge of the retreating wing in sideslip at a rate greater than that established as minimum at zero sideslip was ineffective in improving the lateral control characteristics. The optimum configuration at zero sideslip had no hysteresis of the aerodynamic parameters upon recovery from stall.

McLemore, H. Clyde↗
NASA NTRS1961

Rapid-Transition Tests of a 1/4-Scale Model of the VZ-2 Tilt-Wing Aircraft

An investigation of the longitudinal stability and control characteristics of a 1/4-scale model of the VZ-2 tilt-wing vertical-take-off- and-landing aircraft during rapid transitions has been made on the Langley control-line facility. Only the longitudinal characteristics were studied because with the control-line technique the other phases of the model motion are partially restrained. The rapid transitions from hovering to forward flight could be performed easily at any of the accelerations attempted; whereas, the transitions from forward flight to hovering were generally accompanied by a strong nose up pitching moment which at times was uncontrollable because of an inadequate amount of available pitch control. The model was more difficult to control during rapid decelerations than during slow decelerations and was also more difficult to control for rearward center-of-gravity conditions than for forward ones.

Tosti, Louis P.↗
NASA NTRS1954

Longitudinal Stability Characteristics of the Consolidated Vultee XFY-1 Airplane with Windmilling Propellers as Obtained from Flight of 0.133-Scale Rocket-Propelled Model at Mach Numbers from 0.70 to 1.13

A flight test has been conducted to determine the longitudinal stability and control characteristics of a 0.133-scale model of the Consolidated Vultee XFY-1 airplane with windmilling propellers for the Mach number range between 0.70 and 1.13. The variation of lift-curve slope C(sub L(sub alpha) with Mach number was gradual with a maximum value of 0.074 occurring at a Mach number of 0.97. Propellers had little effect upon the values of lift-curve slope or the linearity of lift coefficient with angle of attack. At lift coefficients between approximately 0.25 and 0.45 with an elevon angle of approximately -l0 deg, there was a region of neutral longitudinal stability at Mach numbers below 0.93 introduced by the addition of windmilling propellers. Below a lift coefficient of 0.10 and above a lift coefficient of 0.45, the model was longitudinally stable throughout the Mach number range of the test. There was a forward shift in the aerodynamic center of about 3-percent mean aerodynamic chord introduced by the addition of propellers. The aerodynamic center as determined at low lift moved gradually from a value of 28.5-percent mean aerodynamic chord at a Mach number of 0.75 to a value of 47-percent mean aerodynamic chord at a Mach number of 1.10. There was an abrupt decrease in pitch damping between Mach numbers of 0.88 and 0.99 followed by a rapid increase in damping to a Mach number of 1.06. The propellers had little effect upon the pitch damping characteristics . The transonic trim change was a large pitching-down tendency with and without windmilling propellers. The elevons were effective pitch controls throughout the speed range; however, their effectiveness was reduced about 50 percent at supersonic speeds. The propellers had no appreciable effect upon the control effectiveness.

Hastings, Earl C.↗
NASA NTRS1974

Wind tunnel tests of an 0.015-scale configuration 140A/B space shuttle orbiter model (67-0) in the NASA/LRC 8-foot TPT to obtain transonic aerodynamic force data (OA106)

These tests were conducted to obtain longitudinal stability and control data for Mach numbers from 0.35 to 1.2. Data were obtained for an alpha range of -2 deg to +22 deg at beta = 0 deg. The effect of speedbrake deflection and body flap deflection was obtained through the Mach range. Boundary layer transition strips were used on the model.

Burrows, R. R.↗
NASA NTRS1981

Aerodynamic characteristics of a series of airbreathing missile configurations

Due to the interest in the application of airbreathing propulsion to missiles and the lack of a suitable data base, an experimental program has been conducted to contribute to such a data base. The configurations investigated were with twin-inlets, either two-dimensional or axisymmetric, each located at three circumferential locations. The effects of a wing located above the inlets and of tail configuration were investigated. Longitudinal stability and control and lateral-directional stability were included in the data obtained. This paper presents a summary of the program and some of the results obtained. Certain trends of the data, as well as problem areas, are discussed. Due to the large volume of data obtained, a detailed analysis is not presented.

Hayes, C.↗
NASA NTRS1984

Development of flight testing techniques

A list of students involved in research on flight analysis and development is given along with abstracts of their work. The following is a listing of the titles of each work: Longitudinal stability and control derivatives obtained from flight data of a PA-30 aircraft; Aerodynamic drag reduction tests on a box shaped vehicle; A microprocessor based anti-aliasing filter for a PCM system; Flutter prediction of a wing with active aileron control; Comparison of theoretical and flight measured local flow aerodynamics for a low aspect ratio fin; In flight thrust determination on a real time basis; A comparison of computer generated lift and drag polars for a Wortmann airfoil to flight and wind tunnel results; and Deep stall flight testing of the NASA SGS 1-36.

Sandlin, D. R.↗
NASA NTRS1958

Qualitative Simulator Study of Longitudinal Stick Forces and Displacements Desirable During Tracking

In this study in which an airplane simulator with one degree of freedom (pitch) was used, results were determined for three conditions of airplane dynamics. For an undamped natural frequency of 1/2 cps with a damping ratio of 0.18 and for an undamped natural frequency of 1 cps with a damping ratio of 0.11, moderate longitudinal stick forces and displacements were desired.

CONTROL, LONGITUDINAL↗
NASA NTRS1955

A Flight Evaluation of the Longitudinal Stability Characteristics Associated with the Pitch-up of a Swept-Wing Airplane in Maneuvering Flight at Transonic Speeds

This report presents the results of flight measurements of longitudinal stability and control characteristics made on a swept-wing jet aircraft to determine the origin of the pitch-up encountered in maneuvering flight at transonic speeds. For this purpose measurements were made of elevator angle, tail angle of attack, and wing-fuselage pitching moments (obtained from measurements of the balancing tail loads).

Anderson, Seth B↗