Accession Number : ADP006062

Title :   3-D Euler Solution for Hypersonic Mach Numbers,

Corporate Author : MESSERSCHMITT-BOELKOW-BLOHM G M B H MUNICH (GERMANY F R)

Personal Author(s) : Pfitzner, Michael ; Weiland, Claus

Report Date : NOV 1987

Pagination or Media Count : 13

Abstract : The development of reusable re-entry vehicles and hypersonic missiles require the control of aerothermal problems. To that end it is necessary to develop new aerothermal prediction methods and to change and extend existing methods, which have been developed for sub- and supersonic flow problems. This paper discusses the integration of the three-dimensional unsteady and steady Euler equations in the regime of hypersonic flow (4 < or = M at infinity < or = 30). The formulation of the Euler equations in quasi-conservative form and the use of a third order upwind biased discretization formula guarantees an accurate and robust algorithm with good shock capturing capabilities. It is found, that with a procedure, where the strong bow shock is fitted and the imbedded shocks are captured, more accurate flow fields with less grid points can be achieved. Results are shown for flow fields around blunted cones with half-angles between delta = 0 deg and 20 deg and angles of attack between alpha = 0 deg and 30 deg for free stream Mach numbers real gas effects become important for M at infinity < or = 4. We discuss the generalization of the basic equations and of the upwind algorithm to deal with a general equation of state. For air the equilibrium equation of state can be calculated through existing Mollier - fit routines. The results of ideal gas calculations with isentropic exponent gamma = 1.4 and gamma = 1.2 are compared with real gas calculations using the effective gamma approach and the full equations for a blunted cone at M at infinity = 15.

Descriptors :   *LIFTING REENTRY VEHICLES, *AEROTHERMODYNAMICS, *HYPERSONIC FLOW, SHOCK WAVES, MACH NUMBER, HYPERSONIC CHARACTERISTICS, MATHEMATICAL PREDICTION, FREE STREAM, ANGLE OF ATTACK, BLUNT BODIES, CONICAL BODIES, SYMPOSIA.

Subject Categories : Fluid Mechanics
      Guided Missile Reentry Vehicles

Distribution Statement : APPROVED FOR PUBLIC RELEASE