• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.157-162
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• 2005

Parallel implementation and performance assessment of the grid assembly in a structured chimera grid approach is studied. The grid assembly process, involving hole cutting and searching donor, is parallelized on the PC cluster. A message passing programming model based on the MPI library is implemented using the single program multiple data(SPMD) paradigm. The coarse-grained communication is optimized with the minimized memory allocation because that the parallel grid assembly can access the decomposed geometry data in other processors by only message passing in the distributed memory system such as a PC cluster. The grid assembly workload is based on the static load balancing tied to flow solver. A goal of this work is a development of parallelized grid assembly that is suited for handling multiple moving body problems with large grid size.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.10
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• pp.669-676
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• 2022

In this paper, the carriage load analyses of stores installed on aircraft are conducted to validate the chimera grid method applied to an unstructured CFD solver, UMSAPv. First, the chimera grid method of UMSAPv is verified for the well-known Eglin Wing/Pylon/Finned store problem. Next, an angle of attack sweep of F/A-18C clean configuration is conducted at a subsonic speed. The computed results are compared with the results of the previous study using MSAPv, a structured CFD solver, to show the validity of Umsapv. Finally, the carriage of F/A-18C JDAM is carried out with a chimera grid as well as a single block grid. The computed results are compared with other computational, experimental and the flight tests.

• 한국전산유체공학회:학술대회논문집
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• 2005.04a
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• pp.21-24
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• 2005

Numerical analysis were made for the unsteady flow fields of the rotor system of a Tilt-Rotor aircraft in cruise mode. The Reynolds-averaged thin-layer Wavier-Stokes equations were discretized by Roe's upwind differencing scheme and integrated in time by the LU-SGS algorithm. The computational domain of the rotor system was constructed by seven multi-block Chimera grids. Comparison of pressure coefficient on the surface of the main wing and blades were made for 3cases of advance ratio(0.325, 0.350, 0.375) and thrust and power coefficients for the rotor were compared with experimental data.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.4
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• pp.1-10
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• 2006

Separation motion analysis of staging system is conducted using combined analysis programs, which include unsteady aerodynamic analysis codes and dynamic motion analysis tools. In this study, the analysis is for the long-rang missile staging system. The purpose of this study is to verify the safety and reliance of the proposed staging system, and to find out the influence of angle of attack perturbation on staging. A structured parallel overset mesh called Chimera grid is used for the simulation of unsteady supersonic Euler flow solver. In addition, unsteady dynamic simulations are also performed.