Large-Eddy Simulation of a Classical Hydraulic Jump: Influence of Modelling Parameters on the Predictive Accuracy

Abstract

Results from large-eddy simulations of a classical hydraulic jump at inlet Froude number two are reported. The computations were performed using the general-purpose finite-volume-based code OpenFOAM®, and the primary goal was to evaluate the influence of the modelling parameters on the predictive accuracy, as well as establish the associated best-practice guidelines. A benchmark simulation was conducted on a grid with a 1 mm-cell-edge length to validate the solver and provide a reference solution for the parameter influence study. The remaining simulations covered different selections of the modelling parameters: geometric vs. algebraic interface capturing, three mesh resolution levels, and four choices of the convective flux interpolation scheme. Geometric interface capturing led to better accuracy, but deteriorated the numerical stability and increased the simulation times. Interestingly, numerical dissipation was shown to systematically improve the results, both in terms of accuracy and stability. Strong sensitivity to the grid resolution was observed directly downstream of the toe of the jump.