阵列射流空间填充水滴形Kagome桁架的靶面冷却性能多目标优化

Multiobjective Optimization of Target Surface Cooling Performance of Array Jet Space Filled With Teardrop-Shaped Kagome Trusses

近年来随着4D打印技术的兴起,力学性能优异的Kagome桁架结构作为新型的扰流单元逐步应用于高换热设备。针对火焰筒中的阵列射流结构,在其射流空间置入水滴形Kagome桁架结构,通过试验验证数值模拟方法;采用数值模拟计算方法,研究了结构参数对靶面换热特性的影响;基于计算数据,拟合了靶面努塞尔数和压损的关联式,并计算出在该结构参数范围下的最优结构。结果表明,拟合二阶响应面模型准确,预测误差小于1.70%。桁架单元结构参数d和α对平均努塞尔数Nuave的影响比较显著,d、α、β2和α^(*)β对压损系数C_(p)的影响比较显著。在最优结构参数d=1.000 mm,α=45.001°,β=46.623°的情况下,Nuave、C_(p)和综合影响因子F的优化结果与模拟结果误差分别为1.24%、0.18%和1.20%。优化件相比于试验件C_(p)减少了0.93%,Nu增加了12.78%,F增加了13.13%。

With the rise of 4D printing technology in recent years,Kagome truss structure with excellent mechanical properties is gradually applied to high heat transfer equipment as a new type of disturbance unit.For the array jet structure in the flame cylinder,a teardrop-shaped Kagome truss structure was placed in its jet space and the numerical simulation method was verified through experiments;the influence of the structural parameters on the heat transfer characteristics of the target surface was investigated by numerical simulation calculation method;The correlation equations of the Nussle number and the pressure loss of the target surface were fitted based on the calculated data,and the optimal structure was calculated under the range of the structural parameters.The results show that the fitted second-order response surface model is accurate with the prediction error being less than 1.70%.The effects of truss structural parameters d andαare more significant for average Nussle number Nuave,while d,α,β2 andα^(*)βare more significant for pressure loss coefficient C_(p).When the optimal structural parameters are d=1.000 mm,α=45.001°,β=46.623°,the errors between the optimized results and the simulated results for Nuave,C_(p) and comprehensive impact fact F were 1.24%,0.18%and 1.20%,respectively.C_(p) is 0.93%less,Nu is 12.78%more,and F is 13.13%more in the optimized part compared to the test part.