  In this paper, the unified gas-kinetic wave-particle (UGKWP) method has been
constructed on three-dimensional unstructured mesh with parallel computing for
multiscale flow simulation. Following the direct modeling methodology of the
unified gas-kinetic scheme (UGKS), the UGKWP method models the flow dynamics
uniformly in different regime and gets the local cell's Knudsen number
dependent numerical solution directly without the requirement of kinetic scale
cell resolution. The UGKWP method is composed of evolution of deterministic
wave and stochastic particles. With the dynamic wave-particle decomposition,
the UGKWP method is able to capture the continuum wave interaction and rarefied
particle transport under a unified framework and achieves the high efficiency
in different flow regime. The UGKWP flow solver is validated by many
three-dimensional test cases of different Mach and Knudsen numbers, which
include 3D shock tube problem, lid-driven cavity flow, high-speed flow passing
through a cubic object, and hypersonic flow around a space vehicle. The
parallel performance has been tested on the Tianhe-2 supercomputer, and
reasonable parallel performance has been observed up to one thousand core
processing. Due to wave-particle formulation, the UGKWP method has great
potential in solving three-dimensional multiscale transport with the
co-existence of continuum and rarefied flow regimes, especially for the
high-speed rarefied and continuum flow around space vehicle in near space
flight.
