Abstract: In order to apply the high-precision structured grids in the flow field with complicated moving and flexible boundaries, a new adaptive control generation dynamic grids method is developed based on two-dimensional body fitted grids. The grids generation method is proposed to generate updated high-precision body fitted structured grids in each time step according to movements of boundaries. A numerical study of fish-like propulsion is carried out by using the new method, and the high computational cost, the grids intersection and quality reduction have effectively been avoided. It makes a full use of advantages of structured grids in accuracy and rate of grids generation and applicability of turbulence models. This new grid generation method is benefitial to the research of flow problems with the moving and flexible boundaries.

Key words: numerical simulation, complicated flexible movement flow field, dynamic grids method, body fitted structured grids, fish-like propulsion