Numerical modeling of oscillatory turbulent boundary layer flows and sediment suspension

Abstract

In this study, an integrated numerical model is developed and applied to simulate oscillatory boundary layer flows and the corresponding sediment suspension. The model solves the Reynolds-averaged Navier–Stokes (RANS) equations for flows and the transient transport equation for sediment. The turbulence closure is accomplished by the baseline (BSL) k–ω two-equation model. The model is capable of simulating oscillatory boundary flows at different Reynolds number regimes, namely, laminar, transitional and turbulent. The model can provide detailed mean (ensemble average) flow velocity, turbulence characteristics and sediment suspension within the boundary layer. The numerical results of mean flow velocity and turbulence kinetic energy are in agreement with the available experimental data and analytical solutions. In addition, the calculated results of period-averaged sediment concentration are also validated against the measurement data, yet the instantaneous results exhibit small phase differences. The proposed model improves the predictive capability for sediment suspension within boundary layers, which is helpful in defining a suitable model for relevant practical applications in coastal engineering.