Monthly Catalog of United States Government Publications
Monthly Catalog of United States Government Publications

Author: United States. Superintendent of Documents

Publisher:

Published: 1971

Total Pages: 1290

ISBN-13:

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February issue includes Appendix entitled Directory of United States Government periodicals and subscription publications; September issue includes List of depository libraries; June and December issues include semiannual index.

Application of a One-strip Integral Method to the Unsteady Supersonic Aerodynamics of an Inclined Flat Surface
Application of a One-strip Integral Method to the Unsteady Supersonic Aerodynamics of an Inclined Flat Surface

Author: Robert M. Bennett

Publisher:

Published: 1972

Total Pages: 68

ISBN-13:

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The method of integral relations is applied in a one-strip approximation to the perturbation equations governing small motions of an inclined, sharp-edged, flat surface about the mean supersonic steady flow. Algebraic expressions for low reduced-frequency aerodynamics are obtained and a set of ordinary differential equations are obtained for general oscillatory motion. Results are presented for low reduced-frequency aerodynamics and for the variation of the unsteady forces with frequency. The method gives accurate results for the aerodynamic forces at low reduced frequency which are in good agreement with available experimental data. However, for cases in which the aerodynamic forces vary rapidly with frequency, the results are qualitatively correct, but of limited accuracy. Calculations indicate that for a range of inclination angles near shock detachment such that the flow in the shock layer is low supersonic, the aerodynamic forces vary rapidly both with inclination angle and with reduced frequency.

A Time-dependent Method for Calculating Supersonic Angle-of-attack Flow about Axisymmetric Blunt Bodies with Sharp Shoulders and Smooth Nonaxisymmetric Blunt Bodies
A Time-dependent Method for Calculating Supersonic Angle-of-attack Flow about Axisymmetric Blunt Bodies with Sharp Shoulders and Smooth Nonaxisymmetric Blunt Bodies

Author: Richard W. Barnwell

Publisher:

Published: 1971

Total Pages: 84

ISBN-13:

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A time-dependent numerical method for calculating supersonic flow about blunt bodies at large angles of attack is presented. The axisymmetric bodies with sharp shoulders which are treated are constructed with a generator composed of segments of constant curvature. The nonaxisymmetric bodies have continuous slope and curvature. All flow fields are inviscid and adiabatic and have one plane of symmetry. A modification to the method of characteristics is introduced for use at the shock wave. A two-step finite-difference method of second-order accuracy is used at the body surface and in the region between the shock and body. A new finite-difference technique is introduced for use at sharp sonic shoulders. Comparisons of the results of the present method with experiment and the results of other methods are made for the flow of equilibrium air past the Apollo command module at the trim angle of attack and for perfect gas flow past a spherical cap and a spherically blunted cone at angle of attack. Both the cap and the blunted cone are terminated with sharp shoulders. Results are presented also for perfect gas flow past a prolate spheroid with its major axis normal to the flow.