Unsteady flow characteristics and viscous flow losses behind multiple rows of circular pin fins in coolant channels

This article deals with a computational assessment of 3D viscous flow behind multiple rows of circular pin fins in coolant channels used in gas turbine systems. Unsteady oscillations and turbulent flow characteristics especially near the endwall surfaces generate the much needed heat transfer enhancement that is usually from the walls to the coolant fluid. The current study is about a comprehensive assessment of present day computational fluid dynamics solvers for the enhancement of wall to coolant heat transfer rates. The paper presents details regarding many flow characteristics, including particle streamlines, as well as total pressure, turbulent kinetic energy and hub heat transfer coefficient contours. The endwall fence placed upstream of the cylinder generates a measurable increase in heat transfer rates downstream of the cylinder. The paper also includes a number of suggested ways to enhance endwall heat transfer rates for use in gas turbine cooling configurations and total pressure improvements near the turbine hub endwall.