A Parallel RBF Mesh Deformation Method with Multi-greedy Algorithm in OpenFOAM

Radial Basis Function(RBF) mesh deformation method has been widely used in CFD simulations with moving boundaries due to its high robustness and accuracy. The original implementation of the RBF mesh deformation method in OpenFOAM(a widely used CFD software) is purely serial with relatively low computational performance. To reduce the time cost of the mesh motion in large-scale simulations, this paper proposes a parallel RBF mesh deformation method with multi-greedy algorithm in OpenFOAM. The proposed multi- greedy method could reduce the control points used by the RBF interpolation on both the moving boundary and the static boundary, which is more applicable than the previous typical greedy algorithm. Based on a master-worker algorithm, the computation of the mesh deformation is highly parallelized. Tests on the benchmark of a three-dimensional moving fish show that with an error tolerance of 1e-4, the interpolation time of the internal mesh motion using our multi-greedy method is about 10.2 times faster than the original one, and with a parallelism of 132, the time cost of the whole mesh motion is greatly reduced with a speedup of 37.