The blob projection method for immersed boundary problems

A new finite difference numerical method for modeling the interaction betwe en flexible elastic membranes and an incompressible fluid in a two-dimensio nal domain is presented. The method differs from existing methods in the wa y the forces exerted by the membranes on the fluid are modeled. These are d escribed by a collection of regularized point forces, and the velocity fiel d they induce is computed directly on a regular Cartesian grid via a smooth ed dipole potential. Comparisons between this method and the immersed bound ary method of Peskin and McQueen are presented. The results show that the m ethod proposed here preserves volumes better and has a higher order of conv ergence. (C) 2000 Academic Press.