Numerical Study On The Optimization Design Of Cooling Structures In The Turbine Blade Cooling Passages

The work in this paper is a basic research in terms of the shortcoming of design foundation for the internal cooling channel structure in current engine turbine blades.The research is aimed at the optimization design of the cooling passage with V ribs or triangular pyramid vortex generators.The flow and heat transfer mechanism of the cooling channel is analyzed by CFD numerical simulation method(FLUENT,RNG turbulence model,enhanced wall function),and then the structural design parameters are determined.First,by comparing the characteristics of heat transfer and flow in the cooling passage,it can be concluded that different discrete and staggered positions and discrete length have a huge effect on the heat transfer and pressure loss.The case of intermediate discrete V-shaped rib is the best.The case of near-wall discrete V-shaped rib has a little pressure loss.But its heat transfer coefficient is lower than that of the continuous V-shaped rib.So the case has poor performance.Besides,compared to the discrete case,discrete and staggered cases have significant increase in heat transfer coefficient with a slight increase in pressure loss.And appropriate increase in discrete length is beneficial to enhance heat transfer and improve temperature distribution uniformity.This paper also suggests a way to enhance heat transfer by making vertical vortexes with triangular pyramid vortex generators.The study focuses on the differences between cases of windward and leeward conditions,streamwise spacing,stagger arrangement by comparing the characteristics of heat transfer and flow in the cooling passage.The study sh ows in contrast with the case of V-shaped ribs,the pressure loss can be drastically reduced by using triangular pyramid vortex generators.The pressure loss is almost the same in cases of both windward and leeward conditions.But the case of leeward condition shows much better heat transfer effect.Changes in streamwise spacing can slightly improve heat transfer and flow.The case of stagger arrangement can cause the increased intensity of the strip high temperature zone and make heat transfer worse.Reducing the distance between the vortex generators and the both sides of the wall can make the low-speed zone unable to expand and improve the flow near the wall.The case of the triangular pyramid vortex generators can be studied further as an alternative solution used in turbine blade cooling passages.