A study of the effect of curvature and pressure gradient on aerodynamics performance and turbulence structure of S-shaped compressor transition duct

Abstract

ABSTRACT The overall performance of the high-pressure compressor in a turbofan engine entirely depends on the flow supplied by the upstream transition duct. A robust and efficient design of the transition duct conveys a highly uniform flow with minimum pressure loss. The present study aimed to determine the effect of adverse pressure gradient and curvature on the flow of the compressor duct. The results suggest that the outer wall curvature causes a significant decrease in from +0.19 to −0.6, and as a result, 75% length of the outer wall is suspended in the favourable pressure gradient. On the contrary, it increases from −0.54 to +0.14 along the inner wall. It implies that most of the inner wall lies in the adverse pressure gradient; consequently, the turbulence structure, mean flow behaviour, and Reynolds stresses are considerably modified. The presence of a strong adverse pressure gradient significantly enhances turbulence quantities along the inner wall. Additionally, the boundary layer parameters grow relatively thicker along the inner wall than on the outer wall. As a result, a considerable increase in the shape parameter (H = 2.12) is obtained.