摘要
为了揭示1+1／2(无低压导叶)对转涡轮进口热斑的迁移特性,运用三维非定常粘性流场计算程序对某1+1／2对转涡轮模型级在不同进口温度分布条件下的流场进行了数值模拟。结果表明,热斑在高压导叶中未发生周向和展向迁移;当进口热斑位于高压导叶流道中间时,高压动叶的热负荷加重;当进口热斑正对高压导叶前缘时,与进口热斑位于高压导叶流道中间方案相比,加重了高压导叶热负荷,但减轻了高压动叶热负荷;综合比较来看,进口热斑正对高压导叶前缘对涡轮冷却设计有利;冷热流体间的滑移速度、二次流效应和浮力效应是影响热斑迁移特性的主要因素;热斑在动叶中的迁移方向主要与冷热流体间滑移速度的方向有关,而与进口热斑相对第一级导叶的位置无关;在高压动叶中,二次流和浮力的作用效果均很明显;在低压动叶中,流体的迁移扩散行为主要受二次流控制,浮力基本不起作用。
In order to reveal the migration characteristics of hot streaks in a Vaneless Counter-Rotating Turbine （VCRT）, a three-dimensional, viscous, unsteady CFD analysis is being performed. The predicted results show that the circumferential and radial movements of the hot streaks in the HPS （high pressure stator） have not been observed. The heat load of the HPR （high pressure rotor） will be increased if the hot streaks don＇t impinge on the HPS. If the hot streaks directly impinge upon the HPS, the heat load of the HPS is increased, but the heat load of the HPR is significantly decreased. All of these indicate that the full impingement case is superior to the no impingement case on the cooling design for the VCRT. The numerical results also show that the migration characteristics of the hot streaks are predominated by the relative slip velocity between hot fluid and cold fluid, secondary flow effect and buoyancy effect. The migration direction of the hot streaks in the HPR is directly related to the relative slip velocity of hot fluid to cold fluid. It is not related to the position of the hot streaks in relation to the HPS. The combined effects of the secondary flow and the buoyancy dominate the migration movements of the hot streaks in the HPR. However, only the secondary flow effect is contributing to the migration of the hot streaks in the LPR （low pressure rotor）.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2007年第1期40-42,共3页
Journal of Engineering Thermophysics
关键词
对转涡轮
热斑
二次流
浮力效应
数值模拟
counter-rotating turbine
hot streak
secondary flow
buoyancy effect
numerical simulation
