Dual numerical solutions for a supersonic laminar flow past a plate and a blunt-fin body junction

Abstract

Results of numerical simulation of supersonic flow past a blunt fin mounted on a flat isothermal plate with a developing laminar boundary layer are presented. Generally, the case considered corresponds to the flow configuration used in the experimental and computational study by Tutty et al. [1], where the laminar air flow with the freestream Mach number of 6.7 past a blunt-fin body located at a distance of 145 mm from the plate leading edge is considered. In the present calculations, the diameter/thickness of blunt-fin (D) was gradually decreased from 2.5 mm to 1.0 mm (ReD = 1.25·104 to 5.0·103). Within the D-range from 2.5 mm to (approximately) 1.85 mm (ReD = 9.25·103), two stable stationary solutions corresponding to metastable flow states with different configurations of the upstream separation zone occupied by horseshoe-shaped vortices were predicted. The metastable solutions differ in the length of the separation zone, location of the main horseshoe vortex, and plate-surface heat flux distribution. One of the solutions predicted at D = 2.5 mm agrees well with the experimental data reported by Tutty et al. [1]. The bifurcation diagram showing the main horseshoe vortex center location versus the Reynolds number is presented. It shows, in particular, that one of the predicted solutions changes evolutionarily with increasing in ReD, whereas the second solution looks as an isolated solution at ReD > ReD,crit. ≈ 9.25·103.