%0 Journal Article
%T 雷诺数和半径比对90°圆弧弯管流动特性的数值研究<br>Numerically Studying Effects of Reynolds Number and Radius Ratio on Flow Characteristics of 90° Arc Bend Pipe
%A 李静
%A 杨俊红
%A 黄涛
%A 韩奎
%A 高琳
%J 机械科学与技术
%D 2017
%X 运用FLUENT软件中的RNG k-ε模型对不同雷诺数Re和不同半径比Rc/D下90°圆弧弯管内的流体流动进行了数值模拟，分析了管内流体的速度场分布、压力场分布以及二次流现象，考察了不同雷诺数Re（1×104≤Re≤1×106）和不同半径比Rc/D（0.6≤Rc/D≤2）组合下72种工况的局部阻力系数以及局部阻力影响长度。结果表明：同一Re下，Rc/D越大，局部阻力系数ξ越小。Rc/D一定时，当Re≤6×105时，局部阻力系数ξ随Re的增大迅速减小；当Re≧6×105时，局部阻力系数ξ随Re的变化很小，几乎趋于不变值。同一Re下，Rc/D越大，局部阻力影响长度越短。局部阻力影响长度随Re的增大先减小后趋于定值，且Rc/D越小，局部阻力影响长度越延后趋于定值。<br>The flow under different Reynolds number Re and different radius ratio Rc/D in 90° arc bend pipe was simulated with the numerical RNG k-ε turbulence model in the software FLUENT. The velocity distribution, pressure distribution and the secondary vortex flow inside the bend pipe were analyzed. The local drag coefficient, the effects of the length of local drag on 72 working conditions with different Reynolds numbers Re (1×104 ≤ Re ≤ 1×106) and different radius ratios Rc/D (0.6 ≤ Rc/D ≤ 2) were analyzed. It is found that Re is constant, the local drag coefficient is reduced when Rc/D increases. Rc/D is constant; Re ≤ 6×105; the local drag coefficient decreases quickly when Re increases; Re≧6×105; the local drag coefficient change with that of Re is very small. Re is constant; the greater Rc/D, the shorter the length of local drag influence. The effect of the length of local drag influence on the increase of Re is reduced and then reaches a constant value; the less Rc/D, the more delay, the longer it takes for the local drag coefficient to reach a constant value
%K 90°弯管
%K 雷诺数
%K 半径比
%K 局部阻力系数
%K 影响长度
%K 数值模拟&lt
%K br&gt
%K turbulence model
%K pressure distribution
%K vortex flow
%K reynolds number
%K local drag coefficient
%K numerical method
%U http://journals.nwpu.edu.cn/jxkxyjs/CN/abstract/abstract6831.shtml