Numerical and Experimental Examination of Turbulent Mixing of Heated Jet in Crossflow

Abstract

The injection of fully developed turbulent heated air from a tube into a cooler turbulent duct flow is examined as a analogy to film-cooled turbine blades. An implicit large-eddy simulation numerical model is applied such that tube and duct turbulence inflow effects are emulated using a divergence-free synthetic eddy method. For direct comparison, a hot-wire experiment is conducted within the Engine Research Building (ERB) test cell SW-6 at the NASA John H. Glenn Research Center. Excellent agreement is obtained for these numerical and experimental results as related to the velocity, temperature, and heat flux for a blowing ratio of 1.2 and by involving a 36 K temperature difference. The relative effect on the solutions of the tube and duct inflow turbulence is systematically evaluated. The impact of inherent low-pass filtering of temperature measurements and probe wire offset on the experimental results are addressed. The validity of the gradient diffusion hypothesis, which is fundamental to Reynolds-averaged Navier–Stokes models, is evaluated.