努谢尔数 meaning in English
nu-number
Examples
- The standard k - e turbulence model was employed in the core region of the cavity . two low reynolds number turbulence models , single equation model and launder and sharma low - reynolds number k - e model , were used in the near wall regions
在紊流核心区采用标准k -模型，近壁区分别采用单方程模型和launder ? sharma低雷诺数k -模型，采用simple算法，求解并获得了盘腔中的速度和压力场、全域的温度场以及流固界面上的换热系数和努谢尔数分布。 - By comparing the results with relative experiment data , it is shown that rng k - is more exactly than the other turbulent model . . 2 ) the influences of axial inflow position , radial outflow size , rotating reynold number , non - dimensional mass flowrate and axial inflow angle on the flow and heat transfer characteristics were numerically investigated for a typical rotator - stator cavity with axial inflow , radial inflow and radial outflow . the correlations for average nusselt number vs rotating reynold number or non - dimensional mass flowrate were established
( 2 )针对一典型的径向、轴向进气，径向出气的转-静盘腔结构，系统研究轴向进气位置、径向出口大小、旋转雷诺数、无量纲质量流量和轴向垂直预旋进气等对盘腔内流动和换热的影响，整理出转-静盘腔内转盘平均努谢尔数与旋转雷诺数无量纲质量流量之间的准则关联式。 - The blade inner channel cooling is a complex convection - conduction coupling problem . this thesis build a three - dimension . compressible turbulence model , and give a general solve method . with the geometrical model of the glossily rectangle straight channel , the rectangle straight channel with in - line arrays disturb plates , the rectangle straight channel with staggered arrays disturb plates , the rectangle straight channel with slant disturb plates , this thesis compute the flow and heat transfer condition when the cold air path though these channels , and gain the temperature field , pressure field , velocity filed , in addition . this thesis also analyze the influence of the different channel height , the different channel materials , the different channels , and gain the function relation between he nusselt number , friction factor and reynolds number . this thesis is emphasis on the new heat transfer enhancement structure , that is , disturb plates , with the comparison with the glossily channel and channel with pin fins , the heat transfer enhancement effect of the former is better , and the conclusion can be used in the design of aircraft blade
叶片内部通道冷却是一个复杂的对流?导热耦合传热问题，本文在分析叶片内部通道冷却的流动与传热情况的基础上，建立了三维、可压缩紊流的物理模型，得到了通用的求解办法；利用不带扰流片的矩形直通道、带顺排扰流片矩形直通道、带叉排扰流片、带倾斜扰流片的矩形直通道的几何模型，计算了冷却空气通过这几种通道时的流动与换热情况，得到了各种不同情况下计算区域的温度场、压力场、速度场；在此基础上分析了不同的通道高度、不同的叶片通道材质对叶片内部通道冷却的影响，并整理得到了各种通道形式下，努谢尔数和阻力因子与雷诺数的函数关系；本文重点研究了新型的叶片内部通道冷却强化传热措施?带扰流片的内部冷却通道的强化传热效果，通过与光滑矩形直通道、带针肋通道的冷却效果的比较，表明了这种新型鲒构的优势，对于叶片内部通道冷却结构的设计可以起到指导的作用。 - 3 ) a custom filed function module was complied to study the influence of non - dimensional mass flowrate changed with time in stair shape on flow and heat transfer inside rotator - stator cavity with axial inflow and radial outflow . average nusselt number takes on a sharp up - down process when the mass flowrate changes from stabile status as to the following change of flowrate , the average nuselt number changes greatly in the initial stage and then changes gradually
( 3 )自编用户程序模块，研究在轴向入流、径向出流的转-静盘腔中，无量纲流量随时间呈阶梯型改变对盘腔流动和换热的影响。当流量从某个稳定状态改变时，转盘上的平均努谢尔数会产生一个明显的上升再降低过程；在每一次流量改变的初始阶段，平均努谢尔数存在一个较大幅度的变化。 - 4 ) in a pre - swirl rotator - stator cavities with discrete pre - swirl nozzles and blade - cooling entry holes , the influences of pre - swirl angle and flow parameter on the flow and heat transfer characteristics were numerically investigated . the correlation for average nusselt number vs rotating reynold number or non - dimensional mass flowrate were established . the results show that : advantage of per - swirl inflow is the effect of cooling the blade - cooling entry holes ; pre - swirl inflow increases heat transfer in rotating disk of pre - swirl chamber ; as pre - swirl angle increases , local nusselt number decreases in pre - swirl chamber ; the temperature of stator of inner rotator - stator chamber and per - swirl chamber decreases as rotating reynold number increases ; when the axial mass flowrate maintains constant , heat transfer in the rotating disk of inner rotator - stator cavities does n ' t change as per - swirl mass flowrate increases , while heat transfer in the rotating disk of per - swirl chamber increases ; when the pre - swirl mass flowrate maintains constant , change of the axial mass flowrate has effect on the whole cavity
结果表明，预旋进气的优点在于增强了叶片冷却孔附近的对流换热效果，局部努谢尔数随预旋角的增大而有所减小；随旋转雷诺数的增加，不论是内转静腔室还是预旋腔室的静盘上的温度都不同程度的降低：当轴向中心进气质量流量不变时，随预旋进气的质量流量增加，内转静腔室的转盘盘面上的换热基本没有变化，而预旋腔室的转盘盘面上的换热效果增强；当预旋进气质量流量不变时，轴向中心进气的质量流量的改变对整个盘腔都有影响。