在本文的研究中,作者嘗試建立一個邊界層-勢流交互作用模式模擬動中的形之流場。在此數學模式中,流場被分爲邊界層與勢流兩區。邊界部份乃以有限差分法配合一個能反應勢流作用的邊界條件求解,而勢流部分則以暫態平板法(Unsteady panel method)配合一個能反應邊界層作用的邊界條件求解。此兩部分交互運算,在計算過程中,兩者將逐步提供對方新的邊界條件直到這些邊界條件和流場的其他性質不再隨計算次數改變爲止。
此模式經建立後曾試著去模擬一些流過翼形之流場,藉結果的分析以確立模式之適用性。此模式能快速地模擬大部份的翼形流場。因而不只具有工程上的應用價值,也可作爲進一步探討諸如動態失速預測、暫態連界層方程式歧異解等問題的基礎。
The incompressible flows over a practical airfoil excuting a pitching motion were simulated by a boundary-layer-potential-flow interaction model. In this numerical model the boundary-layer flow was computed by a finite-difference scheme which made use of an interactive boundary condition and the potential flow was computed by an unsteady panel method involving a blowing-velocity distribution on the boundary, which accounted for viscous effects. After their calculations, both methods provided updated boundary conditions for each other. The calculations were repeated until the solutions converged.
After being developed, this model has been tested with the flows over airfoils excuting some kinds of pitching motions and the results demonstrate reasonable unsteady effects and justify the model. This model does not only simulate a wide range of airfoil flows but also may be a foundation for further exploring to the unsolved problems, such as unsteady boundary layer singularity, dynamic stall onset predictions, and unsteady-flow transition prediction etc.