Simulation of cross-shore breaker bar development utilizing a stabilized two-equation turbulence model.

The performance of a recently developed "stabilized" turbulence (k − ω) closure model, which avoids un-physical over-production of turbulence prior to wave breaking, is investigated in the computational fluid dynamics (CFD) simulation of cross-shore sediment transport and breaker bar morphology. Comparisons are made with experiments as well as results from simulations employing (otherwise identical) "standard" turbulence closure. The stabilized turbulence model is demonstrated to result in major (qualitative and quantitative) improvements of the predicted breaker bar position and height. Conversely, the established over-production of turbulence in the standard closure, coupled with associated inaccurate undertow structure in the outer surf zone, contribute to erroneous offshore migration of the breaker bar. By correcting these shortcomings, the stabilized turbulence closure model rightly predicts initial onshore morphological migration of the breaker bar without any calibration. This work thus establishes proper turbulence modeling as a prerequisite for accurate CFD prediction of cross-shore sediment transport and profile morphology. • A recently developed "stabilized" turbulence model is used to simulate morphology. • The stabilized turbulence model leads to accurate breaker bar position and height. • A standard turbulence model leads to erroneous offshore breaker bar migration. [ABSTRACT FROM AUTHOR]