交错阵列短小柱肋强化传热特性的定量分析

Quantitative Research on the Heat Transfer Enhancement from Staggered Arrays of Short Aspect Ratio Pin Fins

摘要: 短小柱肋阵列在紧凑型换热装置的强化传热中具有广泛应用。对用于受限空间强化传热的小高径比交错阵列柱肋通道进行了数值模拟，研究了展向柱间距、流向柱间距和雷诺数对气动传热特性的影响规律，给出了通道阻力系数和强化传热等级的经验关联式，并基于此对柱间距的影响作了定量分析。结果表明，通道阻力系数随展向柱间距的扩大而减小，但随流向柱间距呈非单调变化，而须在沿程阻力和局部阻力间达到平衡，阻力经验关联式中的指数绝对值表明：流阻更多是受展向柱间距的影响；通道强化传热能力随流向柱间距的缩小而增强，但随展向柱间距呈非单调变化，而须在柱间交互作用和柱侧附面层分离抑制之间达到平衡，传热经验关联式中的指数绝对值表明：传热更多是受流向柱间距的影响。

Abstract: Short Pin Fin array sees a broad range of applications in area of compact heat transfer devices. Computation was conducted for staggered arrays of low aspect pin fins used for enhancing heat transfer in limited spaces. Effect of spanwise and streamwise pin spacing and Re number on the aerothermodynamic performances were investigated. Empirical correlations were established to estimate friction factor and heat transfer enhancement level, based on which a quantitative analysis was conducted for pin spacing. The results indicated that, friction factor increases with expanding spanwise pin spacing, yet no monotonic variation is observed with streamwise pin spacing, as balance is to be achieved between monolith and local resistances. The index value in friction correlation indicates that pressure loss is more influenced by spanwise pin spacing. Heat transfer capacity can be enhanced by increasing streamwise pin spacing, similarly, it doesn’t show a monotonic variation with spanwise pin spacing, as balance is to be achieved between pin-pin in-teraction and depress of boundary layer separation on pin surface. The index value in heat transfer correlation indicates that heat transfer is more influenced by streamwise pin spacing.