摘要
为降低双层壁结构中冲击冷却的横流效应和提升射流的穿透能力,提出了射流孔形状优化方法。将横流干涉射流问题简化为射流柱的绕流问题,采用非均匀有理B样条曲线对圆柱形射流柱参数化,进行拉丁超立方抽样、MATLAB平台中有限元分析工具箱流场求解、神经网络代理模型构建以及遗传算法优化,建立了冲击冷却射流孔形状优化方法;采用RANS方法,结合SST k-ω湍流模型,以平板阵列射流冲击模型为对象,对比分析了圆柱形射流孔和流线形射流孔的流动特性与换热特性。结果表明:与圆柱形射流孔相比,流线形射流孔具有低的绕流阻力和较强的射流穿透能力,其射流偏转情况获得改善,射流冲击的滞止点位置较圆柱形射流孔的更靠近几何滞止点,验证了射流孔形状优化方法的有效性;流线形射流结构的靶面换热效果明显增强,在所计算的横流比为0.3~0.9时,其面平均Nu数提高了6.78%~15.55%;在横流比为0.3、0.5时,靶面换热取决于倾斜的射流冲击和上游涡的强对流换热,流线形射流孔以其较小的绕流阻力能获得更好的冲击冷效和促进上游涡的产生;在横流比为0.7、0.9时,射流明显偏转,靶面换热取决于射流和横流的冲刷作用,此时流线形射流孔以较大的冲击角度要略优于圆柱孔结构;结合换热效果和压力损失,流线形射流孔的热性能因子增幅为2.31%~9.83%。提出并验证了冲击冷却射流孔形状优化方法的可靠性,为燃气透平叶片传热优化提供了一定的参考。
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-ωturbulence 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.
作者
罗培森
邓清华
徐凯颖
王辉辉
丰镇平
LUO Peisen;DENG Qinghua;XU Kaiying;WANG Huihui;FENG Zhenping(School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China;Shanghai Turbine Works Co.,Ltd.,Shanghai 201100,China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2024年第12期57-68,共12页
Journal of Xi'an Jiaotong University
基金
国家自然科学基金资助项目(52276037)。
关键词
燃气透平
冲击冷却
射流
优化方法
热性能因子
gas turbine
impingement cooling
jet flow
optimization method
thermal performance factor
作者简介
罗培森(1999-),男,硕士生;通信作者:邓清华,男,博士,副教授,博士生导师。
