Local entropy generation in an impinging jet: Minimum entropy concept evaluating various turbulence models

Second law analysis techniques have been widely used to evaluate the sources of irreversibility in fluid flow systems. The same technique may be used to evaluate the various turbulence models. In the present study, a local entropy generation rate is computed for a fluid jet impinging on a heated wall. The standard k-ε, low-Reynolds number k-ε and two Reynolds stress models are introduced to account for the turbulence. A numerical scheme employing a control volume approach is used to solve the governing equations. The predictions are, then, compared with the experimental findings in the literature. The local volumetric entropy generation in the region close to the stagnation point is used to evaluate the turbulence models. The entropy generation gives information about the magnitude of viscous dissipation in the flow field. The minimum energy concept alone may not be used to evaluate the various turbulence models, in which case, the experimental measurements are accompanied with the results of entropy analysis.