Groin is expected to be used for various purposes. For each purpose, groin arrangement has been studied comprehensively through observations, experiments and numerical analyses.Flow around a groin has 3-D characteristic. For practical applications, a quasi-3-D numerical model is developed with introduction of hydrodynamic force on groin to predict flow and bed topography. The hydrodynamic force is introduced theoretically by volume integration of Filler equation.
2-D numerical analysis is not effective very much for 3-D flow around a groin. But the 2-D using hydrodynamic force on groin and boundary condition of periodicity is effective in respect of workload. The 2-D numerical model is considered to be able to predict reduction of velocity due to presence of groins. In this paper, we discuss characteristics of experimental flow separation. Pressure fields around the submersible groins for different groin angles from experiment is compared with the 2-D numerical analysis having static pressure distribution. It also describes about capability and scope of application of the 2-D numerical analysis.