Topology optimization of fluidic problems using internal interface normal zero-velocity constraint

One of the disadvantages of the permeability-based fluidic topology optimization method is that seepage inside the solid region makes the optimized results highly sensitive to the selection of the impermeable parameter in the standard Darcy model. In this paper, fluid seepage in the solid region is greatly reduced by imposing zero-velocity constraints along the normal direction of the fluid-solid interface. In each optimization iteration, the fluid-solid interface can be traced by setting a predefined threshold of design variables, and a body-fitted mesh is constructed explicitly by cutting the original square element into quadrilateral and triangular elements. Several representative fluidic optimization examples, for which problems associated with the seepage effect arise when using the standard Darcy model, illustrate the effectiveness of the proposed method.