海流发电用翼型的水动力学模拟

为研究海流各个流动参数同时对水翼水动力学性能的影响,根据海流随机波动特点,选取海流的攻角、雷诺数和湍流强度3个因素,每个因素选取4个水平,进行了L16(43)正交试验设计,对16种方案下的海流发电用翼型NACA63440的水动力学性能进行了定常流动的数值模拟,分析海流的各个流动参数对水翼水动力学特性的影响规律。数值模拟结果表明:海流参数对水翼升阻系数影响的大小依次是湍流度,攻角,雷诺数;其中湍流强度和攻角对升阻力系数影响较为明显,而雷诺数对其影响较小;增加攻角可有效提高升阻比,但存在一极值,超过该极值,水翼将发生失速现象;增大雷诺数可适度提高水翼升阻比;水翼的前半部分是产生升力的主体区域,且在前缘上部存在最易空化的区域。研究结果为进一步研究水翼的水动力特性提供了有益的参考。     

高速诱导轮内部流场的数值计算

基于S-A湍流模型和N-S方程,采用Fluent软件对高速等螺距诱导轮内部流场进行全三维湍流数值模拟,获得诱导轮内部的静压分布、速度分布及内部流线图.分析诱导轮压力面和吸力面存在压差的原因及进口低压区对诱导轮汽蚀性能的影响,得到高速诱导轮内部流场的主要特征,发现诱导轮中最易发生汽蚀的部位为吸力面的进口附近.模拟结果为诱导轮的改进设计提供了理论依据.     

低比转数高速复合叶轮离心泵的优化设计分析

本文根据多年对低比转数高速复合叶轮离心泵的设计和实践，建立了其性能预测的数学模型，并在该模型的基础上提出了以效率为目标函数、以抗汽蚀性能和工作稳定性为约束条件的优化设计方法，对两台比转数为２１和４３的高速复合叶轮离心泵进行了试验验证，表明了本文提出的性能预测模型和优化设计方法是合理可行的．     

小流量高扬程离心漩涡泵气液混输的设计和试验研究

The design method of small-flow high-head centrifugal-vortex pump was presented. This pump, configured with inducer, complex-centrifugal impeller and open-vortex impeller, was put forward to deliver gas-liquid two-phase mixture. An HTB-5/60 type sample pump was developed and tested on a closed-loop test rig. Experimental studies on performance and cavitation tests for gas-liquid two-phase mixture were carried out compared with pure-water experimental results. Also the effect of gas phase on pump was analyzed and discussed. The experimental results show that performance and cavitation characteristics of the sample purnp deteriorates progressively with increasing volume fraction of gas. When the total capacity Qm is between 4.5 m^3·h^-1 and 6 m^3·h^-1 and the gas flow rate qg below 0.66 m^3·h^-1, or qg/Qm is lower than 15%, the characteristic curves are approximately parallel to those in pure water test, but the performance deteriorates sharply until an abrupt flow-cutting at a critical volume fraction of gas. This pump is found suitable for transporting gas-liquid two-phase mixture when working around rated capacity of 5 m^3·h^-1 with qglQm below 15%.