Accession Number : ADA185624

Title :   Turbulence in Hypersonic Flow.

Descriptive Note : Final rept. 15 Dec 86-14 Jun 87,

Corporate Author : HOKENSON CO LOS ANGELES CA

Personal Author(s) : Hokenson, Gustave J

PDF Url : ADA185624

Report Date : 01 Jul 1987

Pagination or Media Count : 79

Abstract : Numerical simulations of hypersonic shear flow, utilizing the full-time-dependent compressible flow Navier-Stokes equations, have been carried out to demonstrate the feasibility of exposing, computationally, the essential structure/physic of turbulent fluctuations in high speed flow. The geometry employed is one of interest to the U.S. Air Force in various applications, namely a right circular cylinder whose axis is aligned with the on-coming flow and around which the cylinder could be rotated. By simulating the flow along a cylinder of the infinite axial extent, an exceptionally quiet flow was established. Due to limitations of computational time, it was necessary to excite artificially this flowfield with periodic suction and blowing located well upstream of the observation plane. As a result, fluctuations in the flowfield entropy, vorticity and pressure were observed which revealed a distinct Mach number dependence. At hypersonic Mach numbers, the fluctuating entropy defined a second boundary layer edge, well beyond that of the vorticity but not propagating deep into the inviscid, flow, as was observed in both transonic and supersonic regimes.

Descriptors :   *HYPERSONIC FLOW, *SHEAR PROPERTIES, BOUNDARY LAYER, EDGES, ENTROPY, FLOW FIELDS, HIGH VELOCITY, HYPERSONIC VELOCITY, FLOW NOISE, NOISE REDUCTION, MACH NUMBER, NUMERICAL ANALYSIS, SUCTION, INVISCID FLOW, DIGITAL SIMULATION, TURBULENCE, TURBULENT FLOW, VARIATIONS

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE