Axisymmetric Impingement Heat Transfer with a Nonlinear κ ― ε Model

摘要

A nonlinear κ ― ε model is applied to predict local convective heat transfer in impinging turbulent axisymmetric jets onto a flat plate. Both the nonlinear constitutive law for the turbulent stresses and the ε transport equation improve the results. Accurate results are obtained for different geometrical setups (in particular a different nozzle-plate distance), both in terms of heat transfer and of flowfield predictions. Reynolds-number dependence of the results is discussed. Second, it is illustrated that the second-order terms in the constitutive law have a negligible influence on the results, except for the turbulent normal stress profiles. Consequently, a first-order model, with locally flow-dependent eddy viscosity, is sufficient to obtain accurate results for the complex test case under study. Comparisons are made to experimental data, to results from a low-Reynolds standard κ ― ε model, and to the v~2-f model.