boundary-layer drag 中文意思是什麼
boundary-layer drag
解釋
附面層阻力-
Airplanes drag along a very thin shield of motionless air known as a boundary layer.
飛機拽著一層很薄的緊貼機面不動的空氣一道向前運動，這層空氣叫做附面層。 -
In the thesis the low drag - low noise optimization of the vehicle main form design is realized, main accomplishments are as follows. researched the knowledge of drag and flow noise, the parameters of the boundary layer are calculated by the hess - smith method and boundary layer momentum integral method. the calculation of the length of transition zone and change in boundary layer displacement thickness between laminar and turbulent states in the transition is improved, then the drag coefficient and self - noise from the transition zone are calculated as the objective functions of the optimization
主要研究內容和成果如下：對航行器繞流流場進行分析，深入研究了阻力和流噪聲產生機理，建立了阻力系數和自噪聲的評估數值計算模型；採用物面分佈源匯法和邊界層動量積分法對繞流流場的流體動力參數進行計算，改進了轉捩區長度和邊界層位移厚度的計算，應用於航行器頭部駐點自噪聲的計算；最後設計了阻力系數和自噪聲數值計算程序模塊。 -
Based on theoretical analysis, microbubble drag reduction is due to structure change of turbulent boundary layer caused by the microbubbles. experiments testify microbubble drag reduction for turbulent boundary layer, as well as bubble size, main flow velocity, etc. affecting the reduction ; with proper flow field model, turbulent model and difference scheme, numerical methods simulate the effect of boundary layer and bubble numbers on dray reduction
理論分析提出微氣泡降阻機理在於其引起湍流邊界層結構的變化；實驗證明了微氣泡對湍流邊界層的降阻作用以及氣泡尺度、主流速度等對降阻作用的影響；數值方法利用適當的流場模型、湍流模型和差分格式，模擬邊界層和氣泡數等對降阻的影響。 -
Experimental investigation of drag reduction mechanism over compliant wall and multi - scale coherent structure control in turbulent boundary layer
柔性壁面湍流減阻機理與多尺度相干結構控制的實驗研究 -
All of the results indicated the turbulent boundary layer had been turned into the laminar layer. the skin friction coefficient drops rapidly. this result not only proved the phenomenon of reverse transition had occurred, but also showed that this condition was drag - reducing condition
實驗結果表明板面附近的流動已由湍流流動轉變為層流流動，同時平板表面的摩擦系數較沒有溫度梯度時有大幅度下降，不僅證明了邊界層逆轉捩現象的存在，也說明了這種條件起到了減阻的效果。 -
Effect of drag reducing grooved surface on high - order moments in turbulent boundary layer
減阻溝槽表面對湍流邊界層高階矩特性的影響
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