Accession Number : ADA116264

Title :   Unsteady Transonic Flows: Time-Linearized Calculations,


Personal Author(s) : Seebass,A Richard ; Fung,K -Y

PDF Url : ADA116264

Report Date : Oct 1980

Pagination or Media Count : 12

Abstract : An accurate and efficient method of computing unsteady transonic flow is described. The flow is linearized about an experimentally measured or numerically calculated steady state, as represented by a given pressure distribution. For a given mode of motion, the amplitudes and phase lags of the lift and moment coefficients at a given reduced frequency are found by superposition from an indicial response. The computational effort is reduced by treating shock waves as discontinuities, and by applying the correct linear far-field behavior. A novel method of modeling the indicial response provides an analytical formulas for the dependence of the amplitude and phase lag on the reduced frequency. (Author)

Descriptors :   *Transonic flow, *Unsteady flow, Airfoils, Mathematical prediction, Coefficients, Amplitude, Two dimensional flow, Time, Linear systems, Harmonic analysis, Indexes(Ratios), Computations, Lift, Moments, Phase, Oscillation, Far field, Shock waves, Jet transport aircraft

Subject Categories : Theoretical Mathematics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE