  The general scheme of two-level parallelization (TLP) for direct simulation
Monte Carlo of unsteady gas flows on shared memory multiprocessor computers has
been described. The high efficient algorithm of parallel independent runs is
used on the first level. The data parallelization is employed for the second
one. Two versions of TLP algorithm are elaborated with static and dynamic load
balancing. The method of dynamic processor reallocation is used for dynamic
load balancing. Two gasdynamic unsteady problems were used to study speedup and
efficiency of the algorithms. The conditions of efficient application field for
the algorithms have been determined.
