查询词典 diffuser

The flowfield and performance of a centrifugal compressor was predicted and analysed, which was composed of a Krain's impeller and two types of vaneless diffuser specially: one was constant area vaneless diffuser and the other was the straight-wall. The results show that the efficiency of the straight-wall vaneless diffuser is obviously lower than that of the constant area, and a separate flow occurs nearby the exit of the centrifugal impeller with the straight-wall diffuser. However, the type of vaneless diffuser has little influence on the aerodynamics performance of the centrifugal impeller. Finally, it is suggested that the constant-area vaneless diffuser should be selected as the downstream extended area of the centrifugal impeller during the prediction for the centrifugal impeller.

对Krain叶轮后带等面积与直壁两种形式的无叶扩压器离心压缩机内部流场进行了计算与分析，结果表明：直壁型无叶扩压器离心压缩机的效率低于等面积无叶扩压器离心压缩机的效率；直壁型无叶扩压器使得叶轮出口的流动出现分离；扩压器的形式对离心叶轮的整体气动性能影响并不大；在进行离心叶轮数值研究时，叶轮后的延伸区最好采用等面积无叶扩压器，以尽量减小无叶扩压器所引起的计算误差。

The the sis compares the vaneless diffuser with the vane diffuser, and indicates that the vane diffuser is propitious to improve the fan performance.

指出了斜流叶轮设置导向叶片扩压器有利于提高风机性能，因此在斜流风机中推荐使用叶片扩压器。

This study presents the investigating of microchannels flow. It is divided into two parts, the flow characteristics of micro venturi and the performance of straight-walled and curved-walled micro nozzle/diffuser respectively. The experimental results are also compared with the simulation results whereby we can observe the flow field in micro venturi and discuss the bounder effect of micro nozzle/diffuser.

本文主要是针对微喷嘴的空气流场进行研究与探讨，研究分为两部分进行，分别是探讨微文氏管的流力特性及曲面微喷嘴边界对流力效能的影响，并将实验结果与CFD软体的分析结果相互比较，藉以观察微文氏管内之流场分布并探讨微喷嘴较佳之流力性能。

Comparison between the velocity distributions at the different flow rate conditions showed that increasing the flow rate was help to improving the velocity distribution. The periodic mean field on r-6 plane at different axis positions showed that the flow within the vaned diffuser, especially within the inlet region, was periodic unsteady when impeller located at the different circumferential position, just as the flow within the vaneless diffuser.

有叶扩压器内平均流场的分析表明，在定常流动的假设下，不同流量工况下有叶扩压器的内部流动也呈现为沿轴线向后盘方向推移流动状况逐渐恶劣的分布规律，表明二元叶片构成的平行直壁有叶扩压器对轴向不均匀流动的掺混作用仍然不大。

On the basis of three dimensional viscous numerical simulation on the internal flow field in the vaned diffuser of a centrifugal compressor,the influence of shaper parameters on the pneumatic performance in low solidity vaned diffuser is compared.

通过对一离心压缩机叶片扩压器内部流场进行三维粘性数值模拟，对比分析了小稠度扩压器的主要形状参数对气动性能的影响。

The results indicate: diversion shell can transform the kinetic energy of fluid into pressure energy well, and eliminate the circumferential component of fluid; the inlet incidence angle of vaned diffuser increases at the condition of O.8Q, and it results in flow separation very likely and the hydraulic loss increases; it is nearly non-impact inflow at the condition of 1.2Q, and the velocity distribution is uniform at the inlet of vaned diffuser and flow separation dose not appear.

结果表明：导流壳能很好地将叶轮中流出的流体的动能转化为压能，并消除速度的圆周分量；在0.8Q工况下，空间导叶的进口冲角增大，容易在空间导叶背面产生流动分离，造成水力损失增加；在1.2Q工况下，空间导叶的进口接近无冲击入流，在进口处流速分布较均匀，其内部未发生流动分离现象。

Such as: calibrating the laser system, calibrating the measurement region and focusing the CCD camera for the diffuser passage with complex shape, selecting the best incidence angle for the laser sheet,, setting the time parameter including the time between pulses and the time between records, designing the laser system, and selecting water fog with 1～5μm diameter as seedings for PIV measurement after comparing several particles. All of the work is useful to accumulate the PIV measurement experience in turbomachinery. 2. Experimental research of the unsteady flow in diffusers The instantaneous velocity fields within the vaneless and vaned diffuser were measured by using PIV technique.

本文在国内首次进行PIV测量系统对离心风机扩压器内部非定常流动的测量，为此，作者作了必要的实验前期工作：双谐振激光器工作特性的标定；针对扩压器复杂的流道形状，解决了片光源照射区域位置的标定和CCD相机的聚焦等问题；为复杂流道形状的扩压器内部流动的PIV测量选择了最佳片光源入射角度；选择了合适的PIV测量时间参数；为实现非定常内流的PIV测量设计了PIV系统的光路布置；根据非接触测量示踪粒子的选取原则，对几种示踪粒子进行了筛选，最终1～5μm的水雾粒子在本文实验条件下获得最佳效果。

At the same time, in the inner unsteady flow-field of vaned and vaneless diffuser, as well as gap between impeller and diffuser has been measured by PIV. The measurement plane is at z=10, 15, 20mm in axial direction from impeller shroud.

对叶轮和扩压器在靠盖侧、跨盘盖中间流面、靠盘侧三个流面，即轴向位置分别为Z=10mm，Z=15mm，Z=20mm三个流面上的速度场进行了实验研究。

Numerical calculation of the unsteady flow within turbomachinery The periodic unsteady flow within impeller/vaneless diffuser or impeller/vaned diffuser was numerical simulated in this thesis. The simulation was calculated on the CFX software flat.

离心风机内部非定常流动的数值模拟本文对叶轮/无叶扩压器和叶轮/有叶扩压器两种结构形式的离心风机内部流动进行了全流场非定常流动数值模拟。

It prove that the hub airfoil-vane diffuser can improve the performance of a compressor with a vaneless diffuser.

只有改善扩压器内气流的流动情况，才能进一步提高气体压力，获得较高的整级效率。

Metrorrhagia is also gynaecological problems of common diseases.

崩漏是妇科常见病也是疑难症。

WordFTP gives you the convenience and timesaving you need.

wordftp让您的方便和省时您所需要的。