An Efficient Multi-Direct Forcing Scheme of Immersed Boundary-Lattice Boltzmann Method

The current high-accuracy fluid-solid coupling algorithms based on immersed boundary method with a multi-direct forcing scheme are not efficient due to the absence of a criterion to stop properly the cycles of the multi-direct forcing scheme with acceptable precision to avoid redundant calculations. Therefore, a criterion based on the immersed forces on different cycles is proposed to end the unnecessary calculations after satisfactory results are obtained during the simulation. The numerical tests are based on immersed boundary-lattice Boltzmann method with a case of an oscillating sphere. The results have shown that the criterion proposed is more efficient than the fixed-number multi-direct forcing scheme to achieve the same accuracy, and the time consumed by the multi-direct forcing scheme with the criterion is significantly less. To extend this approach to other simulations, the threshold of error can be determined by the case configurations.