本研究採用渦流法模擬平面衝擊噴流流場，主要研究目的在於探討平面衝擊噴流場之物理現象。
本文採用隨機走步式之渦流法模擬黏性流場，配合小板法建構出上下兩板固體壁面，以及於小板外置放點渦模擬固體邊界之黏性邊界層。
首先驗證衝擊噴流之特性。模擬結果可將流場分為三個流動區域，(1)自由噴流區,(2)衝擊區,(3)壁面噴流區。自由噴流區具有高斯分布之相似性，另外在壁面噴流區，研究結果可觀察出邊界層的發展以及速度相似性與格勒特紊流理論解相符。模擬結果與文獻實驗數據相比，發現結果相當一致，顯示本文數值方法之可靠性。並探討在不同板距、不同雷諾數對流場特性的影響，發現在同樣的雷諾數下，偏擺之振幅會隨著板距的增加而增大。而當雷諾數減小時，壁面噴流區會有迴流現象的發生。

The evolution of impinging plane jets are simulated by discrete vortex method. The physical phenomena of impinging plane jets are carefully studied in the present study.
The numerical scheme of vortex method with random walk is used to simulate the viscous flow field of impinging plane jets. For the boundary condition processing, the panel method is also included to construct the solid walls of the impingement and confinement plates. In the solid boundaries ,the vortices are emitted outside to satisfy the no slip requirement.
At first, we validate the properties of impinging jets. The results show that the flow pattern can be divided into three characteristics regions : (1) free jet region, (2) impingement region, and (3) wall jet region. The free jet region has the similarity of Gaussian distribution. In addition, we can obtain the development of boundary layer and the similarity of velocity show in good agreement with Glauert theoretical solution in wall jet region. The numerical results are reasonable and consistent with those of available literatures. Then the investigation of the flow field characteristics with different nozzle-to-surface spacing and Reynolds numbers are presented. The results indicate that the larger values of nozzle-to-surface spacing accompany with the larger amplitude of flapping motion at the same Reynolds number. Moreover, the recirculation pattern will occur in wall jet regions at low Reynolds number.

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