基于体积力模型的大S弯进气道与风扇耦合计算研究

Computational Study on S-Shaped Inlet and FanCoupling Based on Body Force Model

关键词:  进气道  Rotor 67  总压畸变  旋流畸变  耦合效应

Key words:  Inlet  Rotor 67  Total pressure distortion  Swirl distortion  Coupling effect

摘要:

为理解超紧凑大S弯进气道与风扇的耦合效应，基于体积力模拟方法开展了一体化计算研究。研究的进气道长径比为2.5，使用Rotor 67进行耦合分析，体积力模型与冻结转子计算得到的总压比、总温比和等熵效率分别相差4.49%，0.26%和2.38%。流场分析表明，风扇对入口段流场影响较为明显，主要体现为畸变区的顺向偏转与微弱衰减；进气道出口畸变经过风扇叶片后得到改善，大低压区和反向旋流基本消失；而流体在叶片的前后缘旋流角与轴向速度的综合改变量越大，风扇对气流做功越多。总的来说，超紧凑大S弯进气道与风扇之间耦合比较明显，需要在设计时进行详细的考察。

Abstract:

Towards understanding the coupling effect between ultra-compact S-shaped inlet and fan, integrated simulation study was carried out using body force modeling method. The inlet model has a length to diameter ratio of 2.5 and Rotor 67 was used for the coupling analysis. The differences between body force modeling and frozen rotor simulation are 4.49%, 0.26% and 2.38% respectively for total pressure ratio, total temperature ratio and isentropic efficiency. Flow field analysis shows that, in the entrance part, the fan has a significant influence on the distorted flow which is co-rotated with the fan and attenuated slightly. The distortion is holistically improved after the fan blades where the large low pressure region and counter-rotating swirl disappear. The more the swirl angle and axial velocity between the leading and trialing edges change, the higher the fan works. In summary, the coupling between the ultra-compact S-shaped inlet and fan is significant and needs to be examined in details.