Accession Number : AD0701854

Title :   DIE THEORIE DER KNALLAUSBREITUNG IN EINER GESCHICHTETEN ATMOSPHAERE (The Theory of Shock Wave Propagation in an Isothermal Atmosphere),

Corporate Author : DEUTSCHE FORSCHUNGS- UND VERSUCHSANSTALT FUER LUFT- UND RAUMFAHRT E V AACHEN (WEST GERMANY)

Personal Author(s) : Stuff,R.

Report Date : 14 OCT 1968

Pagination or Media Count : 11

Abstract : The characteristic method by K. Oswatitsch is modified with respect to the calculation of shock waves from accelerated, decelerated and non accelerated axisymmetric bodies in an isothermal atmosphere. Formulas for the sonic bangs of any aircraft are obtained. The explicit formulas yield satisfying results from a distance of twenty body lengths up to infinity, whereas the formulas by G. B. Whitham give sufficiently exact results only from a distance of thousand body lengths. In stationary flight the shocks are damped with an error function and not as usually assumed with the 3/4 power of the distance. Further, the damping of the shock waves depends the more on the acceleration or deceleration, the larger the distance from the body and the closer the velocity to the speed of sound. The isothermal atmosphere influences the shock strength with increasing distance. (Author)

Descriptors :   (*SHOCK WAVES, PROPAGATION), (*SONIC BOOM, MATHEMATICAL ANALYSIS), ACCELERATION, AXIALLY SYMMETRIC FLOW, DAMPING, WEST GERMANY

Subject Categories : Aerodynamics
      Acoustics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE