Трансформация отрывного турбулентного течения в конической лунке на стенке узкого канала и снижение гидравлических потерь c увеличением конусности

Abstract

Based on the solution of the URANS closed with a modified model of turbulence MSST, the separated flow in a narrow channel with a conical dimple on the wall with a coning angle of θ was calculated. It is noted that there is a sharp transition from the periodic mode with two alternately changing vortices in close to cylindrical (θ = 10о-22.5о) dimples to modes with periodic low-frequency oscillations of inclined mono-tornado structures at moderate θ (30о-37.5о) and with steady vortex structures at θ above 45о. Relative hydraulic losses in the irradiated section of the channel with an increase in θ remain at the level of 1.23-1.24 to θ = 45о, and then quickly decrease by almost 1.5 times to 1.16 at θ = 60о.