Thermal transport due to liquid jet impingement on superhydrophobic surfaces with isotropic slip: Isoflux wall
Thermal transport due to liquid jet impingement on superhydrophobic surfaces with isotropic slip: Isoflux wall
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DOI：
10.1016/j.ijheatmasstransfer.2019.05.113
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发表时间：
2017-11
影响因子：
5.2
通讯作者：
M. Searle;J. Crockett;Daniel Maynes
中科院分区：
文献类型：
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作者：
M. Searle;J. Crockett;Daniel Maynes
对液体水射流撞击具有各向同性滑移的等流量超疏水表面的热输运进行了解析模拟。对输运方程进行了积分分析，得到了常微分方程组的数值解。撞击超疏水表面大大减少了相对于光滑表面的换热，这是由于气体被困在表面的空穴中而引起的。这导致了表面的明显滑移速度和温度跳跃。给出了局部和平均Nusselt数与径向位置(0~45射流半径)、射流雷诺数(3×103~1.5×104)、液体普朗特数(2~11)、归一化滑移长度(0~0.2)和归一化温度跳跃长度(0~0.2)的函数关系。所有结果都与光滑表面上的经典行为(无滑移、无温度跳跃)进行了比较。尽管等流量情形下的局部Nusselt数大于相应的等温情形，但随着温度跳跃长度增加到在超疏水表面上可实现的量，这两种加热条件之间的Nusselt数的差异变得可以忽略不计。这些结果可以用来探索在光滑表面被超疏水表面取代以避免结垢的应用中的传热退化。
Thermal transport due to a liquid water jet impinging an isoflux superhydrophobic surface with isotropic slip was modeled analytically. An integral analysis of the transport equations resulting in a system of ordinary differential equations was solved numerically. Impingement on superhydrophobic surfaces greatly reduces the heat transfer that occurs relative to a smooth surface due to gas trapped in cavities on the surface. This results in an apparent slip velocity and temperature jump at the surface. Local and average Nusselt numbers are presented as a function of radial position (0 to 45 jet radii), jet Reynolds number (3× 10 3 to 1.5× 10 4), liquid Prandtl number (2 to 11), normalized slip length (0 to 0.2), and normalized temperature jump length (0 to 0.2). All results are compared to classical (no-slip, no temperature jump) behavior on a smooth surface. Although local Nusselt numbers for the isoflux scenario are greater than the corresponding isothermal case, the difference in Nusselt number between these two heating conditions becomes negligible as the temperature jump length increases to quantities realizable on superhydrophobic surfaces. These results may be utilized to explore heat transfer degradation in applications where smooth surfaces are replaced by superhydrophobic surfaces to avoid fouling.