Comparison of various integration to wall (ITW) RANS models for predicting turbulent slot jet impingement heat transfer

Abstract

Computations of turbulent jet impinging flow at a Reynolds number of 20,000 and at two values of nozzle to plate spacing equal to 4 and 9.2 have been performed in the present paper. Various Reynolds-averaged Navier–Stokes (RANS) equations based turbulence models, namely, standard k–ɛ, RNG k–ɛ, realizable k-ɛ, Launder and Sharma low-Re k–ɛ, Chang–Hsieh–Chen low-Re k–ɛ, standard k–ω, SST k–ω and v2–f model, have been used. The predictions have been compared with the experimental data on mean velocity, turbulence and heat transfer reported in the literature. The results showed that the accuracy of turbulence models is highly sensitive to the flow conditions. For a small nozzle to plate spacing (4), in which a secondary maxima of Nusselt number is distinct, both the standard and SST k–ω models, along with transitional model, showed best agreement with the experimental data in terms of both fluid flow and heat transfer predictions. In the case of high nozzle to plate spacing (9.2), some of the models considered showed a false secondary peak in the surface Nusselt number. The standard k–ω and standard k–ɛ models only showed good agreement with the experimental data in terms of surface Nusselt number.