三維接合面加裝導流板的馬蹄渦抑制研究

A COMPUTATIONAL STUDY OF CURVED STRAKE TO SUPPRESS HORSESHOE VORTEX AT WING-BODY JUNCTION

The horseshoe vortex due to a boundary-layer flow past a wing-body junction is common in engineering applications. The horseshoe vortex may result in vortical flow, non-uniform wake distribution, and noise signal and affect the efficiency of propulsor. Therefore, the development and suppression of the horseshoe vortex structure are vital engineering issues. In the present study, we introduced a strake to the wing-body junction and conducted a computational parametric study of the strake surface on the development of horseshoe vortex and investigate the effects of suppressing the vortex. The Spalart-Allmaras turbulence model was employed in the computation. The results were examined and we found that the horseshoe vortex can be significantly reduced and the wake flow much more uniform. 三維機翼──平板接合面處所造成的馬蹄渦流場，是許多工程應用上會遇到的問題，由於馬蹄渦會造成不均勻尾流，進而產生噪音訊跡、或影響流場下游的工程應用（如裝推進器等），因此渦流結構的發展與消彌都是工程應用上的重要議題。在本論文中，我們在機翼前方加上導流板（strake），就此板的幾何形狀加以變化，以計算流體力學的方式進行流場的分析，冀圖對後續的流場發展帶來正面的效應，特別是對馬蹄渦的抑制能產生相當的作用。在研究上，我們採用Spalart-Allmaras的紊流模型，並與文獻中的實驗資料來做比較。我們發現：加裝適當的導流罩後，馬蹄渦能大幅度的減弱，流場的均勻度也能獲得適度的改善。