upper twist number 中文意思是什麼
upper twist number
解釋
上捻數-
The surface panel method has been applied to predict the hydrodynamic performance of highly skewed propeller. the surface of propeller and its trailing vortex are discreted by a number of small hyperboloidal quadrilateral panels with constant source and doublet distribution. for highly skewed propeller, the conventional method generating grid oriented along constant radii will result in a high aspect ratio and a high skewness and a twist panel near the propeller tip on blade surface, which result easily in incorrect calculation results of velovity on blade surface, even in iteration divergence and calculation failure. a “ non - conventional grid ” is developed to acoid these problems. this grid can effectively solve the problem of the calculation and convergence for highly skewed propeller. the non - linear kutta condition of equal pressure on upper and lower at the trailing edge is executed by the iterative procedure. by sample calculating, the obtained results are satisfied the experimental data
採用面元法預報大側斜螺旋槳水動力性能，螺旋槳表面及尾渦面離散為四邊形雙曲面元，每個面元上布置等強度源匯和偶極子分佈.對于大側斜螺旋槳而言，槳葉表面採用常規的等半徑網格劃分方法在近葉梢處將導致大展弦比、大側斜和扭曲面元，這容易使槳葉表面速度的計算結果不正確，甚至會導致迭代過程發散及計算失敗.文中建立了一種「非常規網格」劃分方法，能有效地解決大側斜螺旋槳的計算和收斂問題.槳葉隨邊處通過迭代實現非線性等壓庫塔條件
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