In the field of Computational Fluid Dynamics (CFD), there are two categories of numerical methods for simulating moving boundary flow problems. One is the moving grid method, which constantly updates the grid according to the position of object. The major limitation of moving grid method is the regeneration of mesh at every time step, which may consume much time and reduce computational efficiency. To overcome this drawback, a pseudo grid-deformation approach was developed. This approach calculates the grid speed through analytical expression of grid movement. The method is feasible to simulate rotational motion of the object. However, to simulate axial motion of the object, the volume change of grid cells should be considered. Another type of approaches for handling moving boundary problems is the field velocity method which adopts the grid speed technique to simulate the velocity change of flow field. This method is especially suitable for calculation of step change of airfoil, and has been successfully applied to calculate the gust response of the airfoil/wing. The method of conventional field velocity is usually used to calculate the indicial response by incorporating unsteady flow conditions via grid movement in CFD simulations. The main privilege of this method is direct calculation of aerodynamic responses to step changes in flow conditions. [
Last date updated on April, 2024