Design of the transfer from lunar orbits to the sun-Earth libration point region by direct searching in the high-fidelity ephemeris model is an accurate but time-consuming practice. A computationally efficient methodo...
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Design of the transfer from lunar orbits to the sun-Earth libration point region by direct searching in the high-fidelity ephemeris model is an accurate but time-consuming practice. A computationally efficient methodology that takes advantage of the patched elliptic restricted three-body problem model, the power of graphics processing unit parallelcomputing, and the programming platform of MATLAB is presented. Taking the CHANG'E-2 extension mission as an instance, the proposed implementation obtains almost identical results with that in the ephemeris model and shows significant speedup. Moreover, the methodology can be carried out on inexpensive hardware platforms. Numerical results demonstrate that significant speedups can be achieved using the graphics processing unit parallelcomputing when compared to solving the same problem on the central processing unit.
A multigrid diagonal implicit algorithm has been developed to solve the three-dimensional Euler equations of inviscid compressible flow on block-structured grids. An improved method of advancing the multigrid cycle ha...
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A multigrid diagonal implicit algorithm has been developed to solve the three-dimensional Euler equations of inviscid compressible flow on block-structured grids. An improved method of advancing the multigrid cycle has been examined with respect to convergence rates, accuracy, and efficiency. In this method, the multigrid cycle is advanced independently in each of the blocks, and the information exchange between the blocks is done using buffer arrays, allowing for the asynchronous updating of interface boundary conditions. This updating scheme is used to eliminate the convergence problems found in a previous implementation of the algorithm while retaining its potential for efficient parallel execution. Results are computed for transonic flows past wings and include pressure distributions to verify the accuracy of the scheme and convergence histories to demonstrate the efficiency of the method. Efficiencies that were obtained using a modest number of processors in parallel are also presented and discussed.
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