momentum drag 中文意思是什麼
momentum drag
解釋
沖量阻力-
According to dynamical characteristic of the bubble motion in the flow field, and under the assumptions of isothermal system without interior heat source, uniform bubble size, and ignoring surface tension, the mathematical expressions for interfacial momentum exchanges have been deduced which include drag, virtual mass force, and lift
針對氣液泡狀流中氣泡運動力學特性，在系統絕熱、無內熱源、忽略表面張力、氣泡尺寸均一前提下建立了氣液相間曳力、虛質量力、升力的數學模型表達式。 -
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。 -
Topics include the principles of conservation of mass, momentum and energy ; hydrostatic behavior of floating and submerged bodies ; lift and drag forces ; dimensional anaylsis ; wave forces on ships and offshore platforms ; laminar and turbulent flows
主題涵蓋質量守恆、動量守恆及能量守恆等原理、浮體及沈體之流體靜力行為、升力、拖曳力、因次分析、船舶及離岸平臺上作用的波力、層流及紊流。 -
Based on prandtl ' s momentum transportation, this paper calculates in detail the physical quantities such as eddy viscosities, and ratio of eddy viscosity to motion viscosity, total stresses with respect to relative position in three regions of viscous sub - layer, buffer layer, and main turbulent stream for non - newtonian fluid flowing turbulently in ducts, which according to karman ' s three layer models and measurement of fluid parameters in evaluation apparatus, discusses the influence of polymer drag reduction on flowing properties of non - newton fluid, analyzes quantitatively principle of turbulent reduction phenomenon and condition of increasing reduction rate
摘要以普蘭德動量傳遞理論為基礎，按照卡門的三層模型，通過室內模擬環道用0號柴油及加入減阻劑在圓管內的流動參數的測定，計算了非牛頓型流體管內湍流邊界層的層流內層、過渡層、湍流中心的渦流粘度，渦流粘度與運動粘度比、總應力隨相對位置的變化等定量參數，探討了高分子減阻劑對非牛頓流體流動特性的影響，對湍流減阻現象的機理與增大減阻率的條件進行了定量分析。
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