turbulent boundary layer flow 中文意思是什麼
turbulent boundary layer flow
解釋
邊界層亂流-
Experimental study on the turbulent boundary 1mm layer flow over riblets surface
溝槽面湍流邊界層結構實驗研究 -
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。 -
Refined grids were utilized in a large - eddy simulation model for obtaining high - resolution planetary boundary data and analyzing surface layer turbulence. simulation results showed that refined meshes reduced turbulent contributions of subgrid scales, sensitivity of simulation results to sgs parameters decreased, and features of the whole boundary layer were explicitly resolved better. results also revealed flux - profile relationship correctly in surface layer and a good agreement of turbulent velocity characters with observation. therefore, it concluded that the les method was able for simulation of surface layer flow and turbulence, and might be used for further applications
採用加密網格的大渦模式獲取邊界層風溫場的高解析度模擬結果，並據以分析近地面層大氣的湍流特性。結果表明，較小的網格尺度使次網格湍流貢獻率大為降低，模式計算結果對次網格參數的依賴性減小，邊界層整體特徵得到更好的反映。同時，模擬出的近地面層通量廓線關系及湍流速度特徵與實際觀測結果吻合甚好，表明模式具有反映近地面層平均運動和湍流特性的能力。 -
All the improvements included the modifications on the sound velocity, characteristic mach number and the mach number at the grid interface. several 2d flow fields which had shock, shear flow, rarefaction wave, or turbulent boundary layer and the combination of them were computed
該格式改進了聲速、特徵馬赫數的處理方式，對網格界面馬赫數進行了修正，並求解了含有脫體激波、斜激波、剪切流、膨脹扇、及湍流附面層等流動特徵的復雜流動。 -
3. the characteristics of boundary layer ' s transition, shape and separation are researched. the details as follows : ( l ) airfoil surface is turbulent boundary layer flows ; ( 2 ) velocity figure changed unsteady near the point of boundary layer separation due to randomicity of turbulent flow ; ( 3 ) the airfoil have better state of boundary layer separation and poor stall characteristics because of the upper surface of airfoil is flat
給出了該翼型的附面層特性：翼型表面基本為湍流附面層；在靠近附面層分離位置處，速度型形狀、特別是靠近翼型表面的底部速度型形狀變化不定，是湍流流動的隨機性所致；該翼型具有較好的附面層分離形態，但在失速迎角附近，附面層分離形態變化劇烈、失速特性差，是翼型上翼面形狀較為平坦所致。 -
Navier - strokes equation was solved using simple method. lam - bremhorst k - e was used to simulate turbulent flow. it was indicated in this thesis that a longitudinal vortex would be produced after the jet exhausted from a plate into a boundary layer at a pitch angle and a skew angle
研究結果表明，有一定傾斜角度的單個射流與主流作用后，將在下游產生一個流向渦旋，渦旋使得邊界層內的速度和雷諾應力發生嚴重扭曲，從而形成上洗區域和下洗區域。 -
An experimental study on the turbulent boundary layer flow field and its noise
湍流邊界層流場與噪聲實驗研究
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