前缘弯掠影响子午加速风机内流的研究

THE EFFECTS OF LEADING EDGE SKEWED-SWEPT BLADE ON MERIDIAN ACCELERATION FAN

本文采用三维Navier-stokes方程和k-ε两方程湍流模型,对前缘弯掠子午加速风机的内部流场进行数值分析。通过实验数据、设计参数与计算结果对比,验证数值方法模拟该转子内流场的可靠性。研究揭示了前缘弯掠叶轮的流动机制:前缘弯掠叶轮消除了基准叶轮前缘存在的回流,将端壁区域的低能流体吸收到叶片中部高能主流中,减弱了端部低能流体的聚集,从而减弱了流动损失和流动阻塞,前缘弯掠叶轮出口尾迹衰减比基准叶轮快。证明前缘弯掠改善了叶轮内流及前缘弯掠设计的有效性。发现弯掠叶片的静子在小流量工况,其叶片吸力面附近端壁的低能流体被主流携带往下游的二次流特征,改善了小流量工况下静叶的内流状态。

Internal flow characteristics of meridian acceleration fan with leading edge skewed-swept blade is simulated numerically based on three-dimensional Navier-Stokes equations coupled with κ-ε Turbulence model. The calculated characteristic curve and designed parameter is compared with the experimental data, which indicates that the numerical method is reliable. It shows flow mechanism of leading skewed-swept rotor： the skewed-swept rotor avoids backflow occurring on base rotor leading edge, and that low energy liquid in the end wall region is involved into main flow of blade＇s mid-span, consequently weaken the low energy liquid aggregation in the end wall, decrease the flow loss and blockage. And the attenuation of the trailing wake of leading edge skewed-swept rotor is faster than that of the base rotor. The research proves that the design of the leading edge skewed-swept rotors is effective and it improves the internal flow status of fan. Finally, The numerical simulation and analyses also shows the characteristic that, in low mass flow rate working conditions, low energy liquid in the end wall region of suction surface of the skewed-swept static blade, is involved into the second flow downstream, which improve its internal flow status.