An Adaptive Immersed Boundary Method for CFD Simulation of Multiphase Flows with Moving Internal Bodies

Open Access
Author:
McIntyre, Sean Michael
Graduate Program:
Aerospace Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
January 07, 2011
Committee Members:
  • Robert Francis Kunz, Thesis Advisor
  • Jules Washington Lindau V, Thesis Advisor
Keywords:
  • Multiphase Flow
  • Immersed Boundary Method
  • Water Entry Simulation
Abstract:
With the aim of improving the efficiency of underwater launch simulation, a new direct-forcing based immersed boundary method has been developed for incompressible multiphase flow. Equations for six degree-of-freedom rigid body dynamics based on integration of the force distribution due to the immersed boundary are developed and verified. Octree-based adaptive mesh refinement is incorporated to ensure adequate resolution of flow features such as wakes and stagnation regions, as well as free surfaces and the region occupied by the immersed body. The derived immersed boundary approach for multiphase flow with six degree-of-freedom dynamics and adaptive mesh refinement is verified and validated through a series of simulations and comparison with analytic solutions and experimental data for stagnation point flow, free-fall of spheres in viscous flow, water impact of wedges, and water entry of steel spheres. The results are shown to be in good agreement with available data. Limitations of the method are also identified, along with proposed improvements.