叶片前缘旋流和常规冲击对比数值研究

Numerical investigation on difference between blade leading edge vortex and normal impingement cooling

为了寻求更好的叶片前缘内冷结构,对旋流冲击和常规冲击的流动和传热特性进行了数值模拟,对比研究了二者的涡流结构、传热强度、流动阻力、综合传热性能和热均匀性,研究了通道Re数和冲击间距对这些参数的影响。结果表明旋流冲击形成的旋涡有利于传热的增强和热均匀性的提高。在所研究的Re数（2×104~7.78×104）和冲击间距（3.3~5倍直径）范围内,旋流冲击与常规冲击相比平均传热增强18%~34%,增幅随Re数和冲击间距的增大而增大;流阻增大10%~26%,增幅随Re数和冲击间距的增大而减小;综合传热性能增强20%左右;热均匀性提高60%左右。

Numerical simulations for the flow and heat transfer of vortex and normal impingement cooling on the internal channel of blade leading edge were carried out to find better cooling configuration.Comparisons were made between these two cooling forms in such aspects as vortex structure,heat transfer enhancement,pressure loss,thermal performance and thermal uniformity.The influences of Reynolds numbers and spaces between impingement holes on these parameters were studied.Results show that the heat transfer rate is enhanced and the thermal uniformity is improved by the swirl flow created by vortex impingement.Comparing vortex impingement with normal impingement at the range of Reynolds number from 2×104 to 7.78×104 and spaces between impingement holes from 3.3 to 5 times diameter,the averaged heat transfer rate is increased by 18%~34%,and the increment goes up with the increase of Reynolds number and impingement spacing.Pressure loss is increased by 10%~26%,and the increment goes down with the increase of Reynolds numbers and impingement spaces.The thermal performance parameter is increased by 20%,and the thermal uniformity is improved by 60%.