Abstract: A discrete conservative remapping algorithm based upon refinement and numerical integrals,named particle remapping algorithm,is presented.The mass density distribution is chosen as either a piecewise constant with first-order accuracy or a piecewise linear distribution with second-order accuracy.It results in a first-order and a second-order algorithm.The density gradient is evaluated by an area average method with a piecewise linear distribution.On a staggered mesh,in which velocity is vertex-centered,an auxiliary mesh is introduced,and the velocity is remapped.The particle remapping algorithm can be applied to a structured or an unstructured mesh.It does not require a one-to-one mapping between the old and the new meshes.Numerical results show that the first-order algorithm is robust but has an excessive diffusion.The second-order one is better in shape-preservation but violates the monotonicity sometimes.To improve the monotonicity,a conservative mass repair algorithm for structured grids is extended to unstructured grids preserving upper and lower bounds of the density.Several remapping results are presented and the errors are analyzed.

Key words: conservative remapping, particle, staggered mesh, auxiliary grid