预旋对蜂窝密封和迷宫密封内流动传热特性影响

采用数值求解三维RANS方程技术，研究了进口预旋对典型航空发动机用光滑面迷宫密封和蜂窝密封的泄漏流动和传热特性的影响规律。计算了-0.3，0，+0.3三种预旋工况下，两种密封的流动特性和温升特性随压比的变化关系。计算结果表明：预旋对密封的泄漏特性和子午面上的流场形态的影响十分微弱；在相同压比条件下，正预旋会导致密封的总温升减小，而负预旋会导致密封总温升增大；蜂窝面的阻尼作用会削弱预旋对密封内温升特性的影响；进口无预旋或施加正预旋时，蜂窝密封的间隙热能比光滑面迷宫密封大，但进口施加负预旋时恰好相反。

Influence of Inlet Preswirl on Discharge and Heat Transfer Characteristics of Honeycomb and Smooth L

Three-dimensional Reynolds-Averaged Navier-Stokes(RANS) equations were numerically solved to investigate the influence of the inlet preswirl on discharge and heat transfer characteristics in honeycomb and smooth labyrinth seals. The discharge and total temperature rise characteristics, as well as the leakage flow field of these two different seals, were also obtained under five different pressure ratios at inlet preswirl ratios of -0.3, 0, +0.3. The results show that the influence of the inlet preswirl on the leakage flow rate and meridian flow structure is nearly negligible for both honeycomb and smooth labyrinth seals. Positive inlet preswirl can decrease the total difference between the seal inlet and outlet, while the negative preswirl will cause the opposite effect. The damping effect of the honeycomb can reduce the influence of the inlet preswirl on the total temperature difference. The computed windage heating power of the honeycomb seal is larger than that of smooth labyrinth seal with positive or without inlet preswirl, as opposed to the negative inlet preswirl condition.