• Title/Summary/Keyword: inner iteration loop

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Calculation of Low Aspect Ratio Wing Aerodynamics by Using Nonlinear Vortex Lattice Method (비선형 와류격자법을 이용한 낮은 종횡비 날개의 공력특성 계산)

  • Lee, Tae-Seung;Park, Seung-O
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.11
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    • pp.1039-1048
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    • 2008
  • new computational procedure for the Non-Linear Vortex Lattice Method (NLVLM) is suggested in this work. Conventional procedures suggested so far usually involves inner iteration loop to update free vortex shape and an under-relaxation based iteration loop to determine the free vortex shape. In this present work, we suggest a new formula based on quasi-steady concept to fix free vortex shape which eliminates the need for inner iteration loop. Further, the ensemble averaging of the induced velocities for a given free vortex segment evaluated at each iteration significantly improves the convergence property of the algorithm without resorting to the under-relaxation technique. Numerical experiments over several low aspect ratio wings are carried out to obtain optimal empirical parameters such as the length of the free vortex segment, the vortex core radius, and the rolled-up wake length.