Heat transfer characterisation of impinging flame jet over a wedge

Abstract

This paper aims to estimate two unknown parameters - Nusselt number and effectiveness – analytically and study the heat transfer characteristics of impinging flame jet over a wedge-shaped structure similar to a missile deflector plate. Experimentally obtained raw transient temperature history at the non-impinging face of a 4-mm-thick test object made of stainless steel is the only input data. An analytical Inverse Heat Conduction Technique based on Green's Function Approach is employed to estimate both parameters simultaneously. Multiple experimental cases are considered in this work by varying methane-air gas mixture Reynolds number (800, 1000, 1200, and 1500), non-dimensional nozzle tip to test object distance (2, 4, and 6), and wedge-angle (90° and 120°). The observations concerning heat transfer characteristics of the impinging flame jet are discussed in detail. The flame jet's heating effect has been observed to improve as the wedge angle is increased from 90° to 120°. Uncertainty of the estimated parameters is evaluated using the Monte Carlo technique. © 2021