以離散渦流法模擬單一向後突張流暢

本文以離散渦流法（Discrete-vortex method）模擬單一向後突張流場，並計算探討在紊流層中擾動量的輸送現象。離散渦流法已成功的運用在流體流過單一圓柱體與一個垂直平板上。木文主要研究的目的乃擴展離散渦流法來摸擬單一向後突張的流場。主要的技術乃在剪力層上，從近後突張面的一些點（剪力層的厚度），依一個近似的時間間隔導入離散渦流於流場中。本文所得的計算結果與實驗或傳統現象論比較，發現除了近後突張面外整個流場物理趨勢還算合理。由此印證了離散渦流法的簡單與可行性。

關鍵字

離散渦流法；向後突張；數值模擬；庫塔條件

並列摘要

The study of this paper is that the discrete-vortex method simulates the separated flow in a single downward-facing step, and calculates the timedependent instantaneous local momentum fluctuation. The discrete-vortex simula-tion of some turbulent flows has been demonstrated as a powerful technique in modeling the flow over a bluff bodies at high Reynolds number, such as flow over a single cylinder and over two successive cylinders, flow over an inclined plate. The major objective of this paper is to extent the discrete vortex method simulation the separated flow in a single downward-facing step. The main technique is that the shear layers emanating from the edges of the downward-facing are represented by an array of discrete vortexes introduced into the flow field at appropriate time intervals at some fixed points near the edges of downward-facing. The strength of the nascent vortices are chosen so as to satisfy the Kutta condition at the edges of the downward-facing. From the comparison between calculative result of the study and experiment or traditional transport phenomenon, we can find that except near downward-facing, the physical tendency of flow field is reasonable. Therefore discrete-vortex method to prove for solution of a single downward facing step problem.

並列關鍵字

discrete vortex method ； downward facing step ； numerical simulation ； Kutta condition

國際替代計量

以離散渦流法模擬單一向後突張流暢

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