通过引入沿流向行波扰动实现平行穿孔板间空间发展流的异类传热强化
Dissimilar heat transfer enhancement in spatially developing flow between parallel perforated plates by inducing a streamwise travelling-wave disturbance
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中文总结 AI 辅助
本研究提出用平行穿孔板被动诱导行波扰动，在Re=1500、L_p/L_s=6时获超30%类比因子提升，低雷诺数下也能实现异类传热强化。
中文摘要 AI 辅助
类似行波的壁面吹吸是一种以最小压力阻力损失强化传热的有效方法，但以被动方式实现此类异类传热强化效果仍是一项挑战。本研究提出引入平行穿孔板来被动诱导类似行波的扰动，对平行穿孔板间的空间发展层流开展了孔解析模拟，研究范围涵盖雷诺数Re=500-1500、孔与固体长度比L_p/L_s=0-10。在Re=1000且L_p/L_s=9-10、Re=1500且L_p/L_s=4-7时，确认存在异类传热强化效果；在Re=1500且L_p/L_s=6时，获得最高的类比因子（斯坦顿数与摩擦系数的比值），相比不可渗透固体板的类比因子提升超30%。对脉动场的分析表明，在行波流态下，压力诱导的法向壁面速度脉动将温度脉动从穿孔板处输运出去，同时打破流向与法向速度脉动间的相关性，这提升了穿孔板附近湍流热通量相对于雷诺剪切应力的比值。本研究结果表明，引入具有合适孔隙率的穿孔板可诱导行波速度扰动，即便在标准不可渗透平壁产生稳定层流的低雷诺数下，也能实现显著的异类传热效果。
英文摘要
Travelling-wave-like wall blowing and suction is an effective approach for enhancing heat transfer with a minimal pressure drag penalty. However, achieving such a dissimilar heat transfer enhancement effect in a passive manner remains a challenge. In the present study, we propose introducing parallel perforated plates to induce travelling-wave-like disturbances passively. Pore-resolving simulations of a spatially developing laminar flow between parallel perforated plates are performed across a wide range of Reynolds numbers of $Re = 500-1500$ and pore-to-solid length ratios of $L_\mathrm{p}/L_\mathrm{s} = 0-10$. Dissimilar heat transfer enhancement is confirmed for $9 \leq L_\mathrm{p}/L_\mathrm{s} \leq 10$ at $Re = 1000$ and $4 \leq L_\mathrm{p}/L_\mathrm{s} \leq 7$ at $Re = 1500$. The highest analogy factor, i.e., the ratio of the Stanton number to the friction coefficient is obtained at $Re = 1500$ and $L_\mathrm{p}/L_\mathrm{s} = 6$, yielding an increase of more than $30$\% compared to that of an impermeable solid plate. Analysis of the fluctuating fields shows that, in the travelling-wave flow regime, a pressure-induced wall-normal velocity fluctuation transports temperature fluctuations away from the perforated plate, while breaking the correlation between the streamwise and wall-normal velocity fluctuations. This enhances the turbulent heat flux relative to the Reynolds shear stress near the perforated plate. The present results indicate that introducing a perforated plate with a suitable porosity induces travelling-wave velocity disturbances and also achieves a considerable dissimilar heat transfer effect even at low Reynolds numbers where a standard impermeable flat wall yields a steady laminar flow.
