Abstract: A physical process is simulated by storing in a memory state vectors for voxels and a representation of at least one surface. The state vectors include entries that correspond to particular momentum states of set of possible momentum states at a voxel. Interaction operations are performed on the state vectors to model interactions between elements of different momentum states. In addition, surface interaction operations are performed on the representation of the surface. The surface interaction operations model interactions between the surface and elements of at least one voxel near the surface. The elements have a tangential momentum relative to the surface, and the surface interaction operations retain at least a portion of the tangential momentum of the elements. The portion of tangential momentum retained corresponds to a friction parameter. The friction parameter is varied based on changes in pressure near the surface.

Abstract: A computer implemented method for simulating a physical process. The method includes storing in a memory a state vector for each of a number of voxels (i.e., lattice sites). Each state vector includes a plurality of integers, each of which corresponds to a particular momentum state of a number of possible momentum states at a voxel (lattice site) and represents the number of elements having the particular momentum state. Each integer has more than two possible values. The method also includes performing interaction operations on the state vectors that model interactions between elements of different momentum states and performing move operations on the state vectors that reflect movement of elements to new voxels.