渦流粘度 的英文怎麼說
中文拼音 [guōliúniándù]
渦流粘度
英文
eddy viscosity-
In this paper, some characteristics of flow movement and sediment transport are analyzed by using the flume experiment data. the cross section of compound channel can be divided into four regions : the undisturbed region in main channel, the interactive region between channel and plain, the undisturbed region in flood plain and the boundary region. in the undisturbed regions, the distribution of longitudinal velocity along the depth has the feature of lograithmic. whereas, in the interactive region, the longitudinal velocity does not obey the logarithmic distribution law, but it can expressed as a revised logarithmic function by using a wake function. on the basis of the kinematic equation the velocity distribution of transverse velocity is obtained. in the boundary region, the longitudinal velocity obeys the law of parabolic distribution. furthermore, according to the simplified diffusion equation, the transverse distribution of sediment concentration in the interactive region is deduced. the analysis is in good agreement with the measured data
本文根據漫灘水流的運動特點，將漫灘水流的復式斷面分為主槽平衡區、灘槽交互區、灘地平衡區及邊壁區等4個區，並給出了各區寬度的經驗公式.根據灘槽交互區垂線流速分佈的變化特點，提出了附加尾流函數的對數流速分佈公式.在簡化水流運動方程和泥沙擴散方程的基礎上，對灘槽交互區內垂線平均流速及含沙量沿橫向分佈進行了理論分析，提出了反映灘槽水流動量交換強度的橫向渦量粘性系數及橫向擴散系數的表達式，得到了漫灘水流垂線平均流速及含沙量沿橫向分佈的解析解，並與實測資料吻合較好For the present two les models, adopting the subgrid eddy viscosity concept and introducing the transport equation of turbulence energy k, the subgrid scale turbulence is parameterized by the turbulence energy k and the length scale of turbulence / ( k - 1 model ). in addition, vegetation is considered as an internal source of resistant force and turbulence energy
在應用大渦模擬方法求解數值計算模型控制方程時，亞網格雷諾應力項沿用了亞網格渦粘性系數思路，引入亞網格紊流脈動動能k的輸運方程，建立了關于亞網格紊流脈動動能k和紊流特徵長度l的k - l模型求解。The results of the experiments indicate that : thermal plumes in the mantle ( i. e. mantle plumes ) should be divided into two types, vertical plumes, as mentioned traditionally, and non - vertical plumes, including those of inclined - columns, vortexes, etc., and the former may be only a particular case of the latter ; under the condition of the coriolis force to be ignored
在忽略科里奧利力的情況下，板塊的下插和滯積下沉、巖石圈根的存在以及地幔介質粘度的非均勻分佈等都可能構成不同形狀的障礙導流體，導致地幔的渦旋運動。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。The computations are shown to agree well with available experimental and numerical data and the physics of 3d large - scale flow separations and vortex shedding are confirmed. the simulation of the flow around a maneuvering wigley hull is a demonstration of capability for calculations of sway forces and yaw moments acting on a hull moving obliquely at a large range of yaw angles. the focus of study is large - scale cross - section separation flows, bilge - vortex development along the hull in the longitudinal direction and their effects on hydrodynamic forces
應用所開發的求解器，以wigley船型為算例計算了大角度斜航船體粘性流場和水動力，分析了漂角的變化對船體所受到的粘性水動力的影響，相當精確地預報了以橫流分離和般渦生成與泄出為特徵的操縱運動船體特有流動形態及橫向水動力和轉脂力矩，經與現有試驗和計算數據比較，檢驗和驗證了該求解器精確模擬繞斜航運動船體的大尺度分離流動和計算非線性水動力的能力。The results showed that process parameters varied with time in fermentation was distinct for different agitator and the hydrofoil impeller instead of the disc turbine impeller might significantly reduce power consumption under the same condition
研究結果表明： （ 1 ）與傳統的渦輪攪拌槳相比，翼形軸流槳攪拌其發酵過程參數（粘度、溶氧、效價等）隨時間的變化曲線有明顯的差異； （ 2 ）在相同的生產條件下，用冀形軸流槳代替渦輪槳可有效提高生產效率。This dissertation has on the research and design of a micro turbine engine as background and it is for the purpose of comprehending viscous flow behaviors in micro scaled conditions and that in the mini - turbine cascades. a mini wind tunnel is designed and set up which also can be used in other micro flow experiments. on the basis of this mini wind tunnel, three mini flow experiments, including micro jet experiment, micro boundary layer experiment and mini - turbine cascades experiment, have been carried out
本文以某型微型渦輪噴氣發動機研製為背景，以認識微尺度下粘性流體流動狀態及其機理和微渦輪葉柵通道內部流動特性為目的，設計並搭建了除本實驗外還可供其他流體力學實驗使用的微型風洞，並在該微型風洞基礎上進行了微尺度射流實驗、微尺度壁面邊界層實驗和微尺度渦輪葉柵實驗。If the two - equation turbulence models employ a linear relationship between the reynolds stress and the mean strain - rate tensors, this relationship is known as the generalized boussinesq model, the two - equation models can be extended for a wider range of applicability by developing more advanced nonlinear algebraic relations between the stress tensor and the mean - velocity gradient and the turbulent scales, this is known as explicit algebraic stress models ( easm )
另一個是構成模型，即決定應力張量、應變率張量和兩個湍流尺度因子之間的函數關系式，它決定了雷諾應力。如果構成模型是線性的，則為boussinesq渦粘模型（ evm ） ，如果構成模型是非線性的代數關系式，則為顯式代數應力模型（ easm ） 。分享友人