Numerical Study of Effects of Mach number on Aerodynamic Performance of Large Enthalpy Drop Stationary Cascade

Based on the method to change blade loading type along blade height, that is, applying aft-loading at both end zones of cascade while applying fore-loading in the mid zone of cascade, HTC(Harbin Turbine Company) designed a twisted and bowed stationary cascade with low aspect ratio and large enthalpy drop. To verify the aerodynamic performance of such cascade, firstly, low-speed wind tunnel tests were conducted to validate the calculation results of commercial software CFX, and then numerical simulations were made for the aerodynamic performance of the cascade at different Mach numbers. The simulation results show that the large enthalpy drop stationary cascade designed by HTC can offer good aerodynamic performance while keeping its high-load characteristics in the change range of outlet Mach number as stated in this paper.

通道构型对全热换热器性能的影响

薄膜式全热换热器的通道构型对其性能有重要影响,为改进全热换热器的性能以达到更好的节能效果,研究分析了几种通道结构的流动及热质传递特性,采用数值模拟方法对不同通道构型下全热换热器的性能进行了预测及比较分析。结果表明:正三角形通道全热换热器各项性能指标均最差;对于矩形通道,随着长宽比的增加,显热效率、焓效率及全热交换量变化不大,而压降减小更迅速,导致换热器整体性能有所提高;近无限大平板通道全热换热器各项性能指标均为最佳。结论是通道支撑越少,全热换热器性能越好。