We analyze the effects of the flow parameters and the geometrical parameters on the axial flow , the secondary flow and the friction 分析了各種流動參數和幾何參數對軸向速度、二次流動、壁面摩擦力、摩擦系數比的影響。
The results of test cases indicate that the flow parameters for the final design met the requirements and that the geometric parameters were fairly close to the desired values 算例設計結果表明,最終設計翼型的流動參數和形狀參數都很接近要求的值。
Wave systems are analyzed from predicted flow parameters . combustion state is evaluated from the distribution of chemical component density . therefore , theoretical explanation is afforded to improve and optimize chamber frame 采用預測的流動參數分布云圖分析了波系結構,從化學組分的濃度分布判斷燃燒狀況的好壞,從而為改善優化燃燒室結構提供理論依據。
The conclusion that the optimal secondary nozzle exit area generating the maximum thrust agrees well with the numerical simulation , indicating that the exit area of secondary nozzle should be optimized according to structure and flow parameters during design 表明在引射火箭設計時,應結合引射火箭的結構和流動參數對二次噴管出口面積進行優化設計,以達到最佳推力性能。
Relaxation factors are adopted . a program is produced to simulate swirling air flow in a horizontal straight pipe and compare with experiment data . the simulation prove that the modified k - model can predict the core , annular and wall regions near entrance and axial velocity far from entrance , but it ca n ' t predict tangential velocity well in weak swirling area far from entrance 編程計算水平圓管內螺旋氣流的流動參數并與實驗數據對比,結果表明修正-湍流模型在近入口處基本上能預測出中心區、環形區和近壁區的流動特性,在遠離入口弱旋流區域對軸向速度的預測符合實際情況,但是出現對周向速度修正過大的現象。
A new method should be discovered to design the function block . the thesis is based on the rheology and hydrokinetics of the polymer melt , and calculates the velocity in the die by fem simulation , and provides die design with theory proof . according to the existed theory , i summarize and conclude the fem formula of the polymer flow , and then write the program to calculate on the computer 本論文中功能塊結構的研究,是以熔體的流變性以及流體動力學理論基礎上,對在口模中的熔體進行數值模擬,計算出熔體在口模中的流動參數(主要是速度的分布) ,從而可以科學的對功能塊幾何結構進行優化。
Reynolds numbers ( based on average velocity at passage inlet and hydraulic diameter of the passage ) are changing from 20000 to 80000 and the extraction ratios ( suction ratios , sr ) are changing from 0 . 30 to 0 . 60 for each test model . so the influences of reynolds numbers , suction ratios and etc . on the discharge coefficients and pressure loss characterist ics are also presented . flow fields of typical passages are visualized with the flow visualization techniques and measured with hot - wire anemometer 對每一種通道結構,實驗在不同通道進口雷諾數( re = 20000 、 40000 、 60000 、 80000 )和不同通道總出流比( sr = 0 . 30 、 0 . 45 、 0 . 60 )下進行,以研究這兩個流動參數及其它相應變化的參數(氣膜孔的雷諾數re _ h 、氣膜孔與通道的動量比i等)對出流特性和流阻特性的影響規律。
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。
In the theoretical aspect , performance analytical model of was proposed , in which allowances were made to allow for variable cross - sectional area , include the heat release of chemical reaction , and allow for mass addition . software was generated , and performance of rocket ejector was analyzed accounting for heat release location , flow parameters and structural configuration 在理論方面,建立了引射火箭模態的性能分析模型,該模型考慮了化學反應放熱、加質和變幾何截面的影響;編寫了相應的軟件,并結合放熱位置、流動參數和發動機結構進行了引射火箭的概念設計。