论文部分内容阅读
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(1×104Re1×106)和不同半径比Rc/D(0.6Rc/D2)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Re6×105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。
Using the RNG k-ε model in FLUENT software, the numerical simulation of the fluid flow in a 90 ° arc tube with different Reynolds numbers Re and Rc / D with different radius ratios was performed. The velocity field distribution and pressure field distribution As well as the secondary flow phenomenon, the local resistance coefficients of 72 conditions with different Reynolds number Re (1 × 104Re1 × 106) and different radius ratio Rc / D (0.6Rc / D2) Local resistance affects length. The results show that under the same Re, the larger the Rc / D, the smaller the local resistance coefficient ξ. When Rc / D is constant, the local resistance coefficient ξ decreases rapidly with the increase of Re when Re 6 × 105. When Re ≧ 6 × 105, the local resistance coefficient ξ changes little with Re, Variable value. Under the same Re, the larger the Rc / D, the shorter the influence of the local resistance. The influence length of local resistance decreases with the increase of Re and then approaches the fixed value, and the smaller the Rc / D, the longer the influence of local resistance tends to set value.