1 research outputs found
A parallel dynamic overset grid framework for immersed boundary methods
A parallel dynamic overset framework has been developed for the curvilinear
immersed boundary (overset-CURVIB) method to enable tackling a wide range of
challenging flow problems. The dynamic overset grids are used to locally
increase the grid resolution near complex immersed bodies, which are handled
using a sharp interface immersed boundary method, undergoing large movements as
well as arbitrary relative motions. The new framework extends the previous
overset-CURVIB method with fixed overset grids and a sequential grid assembly
to moving overset grids with an efficient parallel grid assembly. In addition,
a new method for the interpolation of variables at the grid boundaries is
developed which can drastically decrease the execution time and increase the
parallel efficiency of our framework compared to the previous strategy. The
moving/rotating overset grids are solved in a non-inertial frame of reference
to avoid recalculating the curvilinear metrics of transformation while the
background/stationary grids are solved in the inertial frame. The new framework
is verified and validated against experimental data, and analytical/benchmark
solutions. In addition, the results of the overset grid are compared with
results over a similar single grid. The method is shown to be 2nd order
accurate, decrease the computational cost relative to a single grid, and good
overall parallel speedup. The grid assembly takes less than 7% of the total CPU
time even at the highest number of CPUs tested in this work. The capabilities
of our method are demonstrated by simulating the flow past a school of
self-propelled aquatic swimmers arranged initially in a diamond pattern