laminar-turbulent flow 中文意思是什麼
laminar-turbulent flow
解釋
層流湍流-
Regressed the experimental date with linear use minimal dual multiply method. got the empirical equation of heat transfer and flow resistance in laminar, transitive and turbulent zone
Reb隨肋高h 、肋軸向間距pt的增大而減小，隨肋寬的增大而增大。 -
When the flow of fluids in channels or pipes changes from laminar to turbulent as speed of the flow is increased, there is a large increase in drag
流體，如我們常見的水，在管道里流動時，會隨著速度的增加，由規則的層流轉為貌似毫無規律的湍流。 -
For fluids with high viscosities such as polymers, effective mixing is not achievable by turbulent flow and laminar flow is the only method for mixing of fluids with high viscosities
對于聚合物這樣的高粘物系，不可能產生湍流來產生高效混合，層流混合是高粘流體唯一可能的混合方式。 -
The experimental results of the flow characteristics of the mmc heat sink indicate that the critical reynolds number signifying the transition from laminar flow to turbulent flow is in advance ; under the same experimental conditions, the variation in entrance direction of the microchannel inlet and outlet has little effect on the microchannel ; the experimental values of the friction factor of the de - ionized water in a microchannel agree well with those calculated using the theoretical laminar formula ; furthermore, a comparison of the experimental results and simulation results shows that navier - stokes equation and rng - turbulence model can be used to model the laminar and turbulence flow regions in a microchannel ; meanwhile, the correlations of the flow resistance in the turbulent flow regions for the de - ionized water as the working fluids are obtained from experiments
對歧管式單通道熱沉流動特性的研究結果表明，微通道內流體流態由層流向紊流轉變的臨界雷諾數提前;改變流體的進出口方向對熱沉總壓降造成的影響很小;摩擦系數的實驗值與理論值較接近;數值模擬結果能夠與實驗值較好吻合;並由實驗給出了紊流區流動阻力的實驗關聯式。此外，選用十二烷基硫酸鈉（ sodiumdodecylsulphate ， sds ）以及烷基多糖苷（ alkylpolyglycoside ， apg ）作為減阻添加劑，研究了表面活性劑添加對微通道流動特性的影響。 -
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。 -
The numerical analysis indicates that that the multi - longitudinal vortex flow in tubes can markedly enhance both the laminar and turbulent heat transfer with less additional increase of flow resistance
結果表明，管內多縱向渦對層流和湍流換熱的強化效果顯著而流阻增加較少，具有優良的綜合強化換熱性能。 -
The resonant three - wave model and laminar - turbulent velocity profile composed are used as a model of coherent structures in. turbulent flow. the forming and variation of turbulent coherent structures in the channel are simulated by the compact differential method with high accuracy and resolution derived in this paper
以共振三波和層-湍復合速度剖面作為湍流相干結構模型，採用文中所導出的高精度、高解析度的緊致差分方法，模擬了槽道流動在近壁區域湍流相干結構的形成和變化。 -
Pressure discharge relation of the simple orifice is exponential in air and soil. the flow regime of simple emitter is situated between laminar and turbulent
簡易地下滴灌灌水器流量壓力關系在空氣和土壤介質中都呈現較好的冪函數關系，其流態介於層流和紊流之間。 -
Moreover, this paper investigates the influences of surfactant aqueous solutions on flow characteristics of a mmc. sodium dodecyl sulphate aqueous solution and alkyl polyglycoside aqueous solution are used as working fluids. the experiment results indicate that the drag reduction depends on flow velocity and temperature ; the drag reduction effects aren ’ t very obvious in laminar flow region, but when fluid enter turbulent flow region, the drag reduction increase notably, the drag reduction effects
研究結果表明，阻力減小率（ dragreduction ， dr ）與流速和溫度有關;層流區內表面活性劑的減阻效果不是特別明顯，但進入紊流區后減阻效果開始增強，尤其進入旺盛的紊流區后減阻效果大大增強;溫度提升也可增加dr ，但在溫度較高時添加sds后減阻效果的改善卻不及apg 。 -
In the laminar flow regime, a analytical mathematical model is obtained by analyzing the film flowing in the wavy wall tube. in the turbulent flow regime, mathematical model almost ca n ' t be obtained directly because the turbulent flow in wavy wall tube is very complex, the model is obtained by quoting some results which are theorized by other studiers. in the part of experimental study, the flow form in the wavy wall tube is observed by transparent quartz glass wavy wall tube apparatus, the evaporation experiments are carried out in a 3 meters steel wavy wall tube, using glucose as the medium, heat transfer is invested, the heat transfer correlations of wavy wall tube evaporator are obtained
數學模型的建立過程中，對于液膜層流流動，直接對波形管內的降落液膜進行理論分析，得出液膜層流流動下數學模型的解析式；對于液膜湍流流動，由於湍流流動的復雜性，再加上所採用的波形管對湍流流動的影響，直接對降落液膜進行理論分析建立數學模型是極其復雜的，通過採用以前一些研究者得到的理論分析與實驗結果，並引入與波形管的形狀特徵參數有關的修正系數k ，建立液膜在湍流流動下的數學模型。
分享友人