燃气透平冲击冷却的射流孔形状优化方法及验证

To reduce the transverse flow effect of impingement cooling and enhance the jet penetration capability within double-layer wall structures, a method for optimizing jet hole shapes is proposed. The problem of transverse flow interference jets is simplified to the flow around a jet column. Non-uniform rational B-spline curves are used to parameterize the cylindrical jet column. Latin hypercube sampling, finite element analysis toolbox for flow field solutions on the MATLAB platform, neural network surrogate model construction, and genetic algorithm optimization are combined to establish the optimization method for impingement cooling jet hole shapes. Using the RANS method alongside the SST k-ω turbulence model and focusing on the flat array jet impingement model as the object, the flow and heat transfer characteristics of cylindrical jet holes and streamlined jet holes are compared and analyzed. The results show that compared to cylindrical jet holes, streamlined jet holes have lower flow resistance and stronger jet penetration capability. The jet deflection is improved, and the stagnation point of jet impact is closer to the geometric stagnation point for streamlined jet holes, validating the effectiveness of the jet hole shape optimization method. The heat transfer effect on the target surface of the streamlined jet structure is significantly enhanced. The average Nu number increases by 6. 78% to 15. 55% when the transverse flow ratio is 0. 3 to 0. 9. At transverse flow ratios of 0. 3 and 0. 5, the heat transfer on the target surface is influenced by the inclined jet impact and strong convective heat transfer of the upstream vortex. Streamlined jet holes with lower flow resistance achieve better impingement cooling efficiency and promote the generation of upstream vortices. At transverse flow ratios of 0. 7 and 0. 9, the jets deflect significantly, and the heat transfer on the target surface is determined by the scouring effect of the jets and transverse flow. In such cases, the streamlined jet hole structure slightly outperforms the cylindrical hole structure due to its larger impingement angles. Considering both heat transfer performance and pressure loss, the thermal performance factor of streamlined jet holes increases by 2. 31 % to 9. 83%. The reliability of the proposed jet hole shape optimization method for impingement cooling is established, offering insights for optimizing heat transfer on gas turbine blades.