Discrete-Jet Film Cooling: A Comparison of Computational Results With Experiments

James H. Leylek, R. D. Zerkle

1993 · 27 citations · 0 references

Concepts

TL;DR

Large-scale computational studies compare with experiments to understand coolant jet and crossflow interaction in discrete-jet film cooling. Detailed 3‑D elliptic Navier–Stokes solutions with high‑order turbulence modeling simultaneously solve fully coupled flow in the plenum, film‑hole, and cross‑stream regions for a range of parameters typical of gas‑turbine airfoils. Computational results agree well with experiments, complementing and supporting previous interpretations, and explain complex flow within the film‑hole as well as the counter‑rotating vortex structure in the cross‑stream.

Abstract

Large-scale computational analyses have been conducted and results compared with experiments to understand coolant jet and crossflow interaction in discrete-jet film cooling. Detailed three-dimensional elliptic Navier–Stokes solutions, with high-order turbuence modeling, are presented for film cooling using a new model enabling simultaneous solution of fully coupled flow in plenum, film-hole, and cross-stream regions. Computations are carried out for the following range of film cooling parameters typically found in gas turbine airfoil applications: single row of jets with a film-hole length-to-diameter ratio of 1.75 and 3.5; blowing ratio from 0.5 up to 2; coolant-to-crossflow density ratio of 2; streamwise injection angle of 35 deg; and pitch-to-diameter ratio of 3. Comparison of computational solutions with experimental data give good agreement. Moreover, the current results complement experiments and support previous interpretations of measured data and flow visualization. The results also explain important aspects of film cooling, such as the development of complex flow within the film-hole in addition to the well-known counterrotating vortex structure in the cross-stream.