Accession Number : AD0609577

Title :   THE NEAR WAKE OF A WEDGE,

Corporate Author : AVCO EVERETT RESEARCH LAB EVERETT MASS

Personal Author(s) : Weiss,R.

PDF Url : AD0609577

Report Date : DEC 1964

Pagination or Media Count : 47

Abstract : An analytical model of the two-dimensional laminar near wake is described. All relevant physical features of the flow, including the boundary layer expansion at the shoulder, free shear layers, recirculation regions and recompression region are included. A tractable problem is formulated by matching approximate solutions for each of these regions along mutual boundaries. A set of coupled algebraic equations is derived, and numerical results obtained for the conditions of a wind tunnel wedge experiment. Satisfactory agreement is obtained between the measured and theoretical variation of base pressure with Reynolds number. Additional computations are carried out for a series of wedges of different length, apex angle and wall temperature. The variation of base pressure, wake angle and neck enthalpy ratio with altitude is obtained for these bodies. It is shown that the near wake dimensions scale approximately with body size, and that the neck enthalpy ratio has a significant variation with body size, wall temperature and altitude. The effect of free-stream velocity on the neck enthalpy ratio is seen to be relatively unimportant, however. A number of extensions of the first-order model are suggested. (Author)

Descriptors :   (*WEDGES, WIND TUNNEL MODELS), (*WAKE, LAMINAR FLOW), (*FLUID MECHANICS, SEPARATION), TWODIMENSIONAL FLOW, BOUNDARY LAYER, NUMERICAL ANALYSIS, ALGEBRA, EQUATIONS, BASE FLOW, PRESSURE, REYNOLDS NUMBER, STAGNATION POINT, SHEAR STRESSES, AERODYNAMIC CONFIGURATIONS

Distribution Statement : APPROVED FOR PUBLIC RELEASE