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首页> 外文期刊>Experimental Thermal and Fluid Science: International Journal of Experimental Heat Transfer, Thermodynamics, and Fluid Mechanics >Heater size and heater aspect ratio effects on subcooled pool boiling heat transfer in low-g
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Heater size and heater aspect ratio effects on subcooled pool boiling heat transfer in low-g

机译：加热器尺寸和加热器纵横比对低克重过冷池沸腾传热的影响

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Pool boiling heat transfer measurements using heaters of varying aspect ratio were obtained in low-g (0.01 g +/- 0.025 g) aboard the KC-135 aircraft. The heater aspect ratio was varied by selectively powering 2 x 2, 2 x 4, 2 x 6, 2 x 8, and 2 x 10 arrays of heaters in a 10 x 10 heater array containing individual heaters 0.7 x 0.7 mm(2) in size. Electronic control circuitry was used to maintain an isothermal boundary condition on the heater surface while the power dissipated by the heater was measured. The working fluid was FC-72 at 101 kPa and three different bulk subcoolings. Low-g boiling behavior was governed by the dynamics of the primary bubble. For both square and rectangular heaters, CHF appeared to be a result of the competition between increasing heat transfer associated with the satellite bubbles and the decrease in heat transfer due to growth of the dry area under the primary bubble as the wall superheat increases. At low subcooling on rectangular heaters, surface tension acted to pull the bubble into a spherical shape, allowing liquid to rewet the surface. At high subcooling and high superheat, thermocapillary convection caused the large bubbles that formed on the surface to shrink by increasing the condensation on the bubble cap, resulting in more wetted area. The presence of thermocapillary convection at higher subcooolings may be due to FC-72 being a mixture of various components. (C) 2005 Elsevier Inc. All rights reserved.
机译：在KC-135飞机上的低克重（0.01 g +/- 0.025 g）中使用不同纵横比的加热器进行池沸腾传热测量。通过在10 x 10的加热器阵列中选择性地为2 x 2、2 x 4、2 x 6、2 x 8和2 x 10的加热器阵列供电，可以改变加热器的长宽比，其中10 x 10的加热器阵列中包含0.7 x 0.7 mm（2）的单个加热器尺寸。电子控制电路用于在加热器表面维持等温边界条件，同时测量由加热器耗散的功率。工作流体为101 kPa的FC-72和三种不同的整体过冷度。低克沸腾行为受主气泡动力学的控制。对于方形和矩形加热器，CHF似乎是与卫星气泡相关的传热增加与壁过热度增加时，由于初级气泡下面的干燥区域增长而导致的传热减少之间竞争的结果。在矩形加热器的过冷度较低的情况下，表面张力可将气泡拉成球形，从而使液体重新润湿表面。在较高的过冷度和较高的过热度下，热毛细管对流会通过增加气泡帽上的冷凝水而使表面上形成的大气泡收缩，从而导致更大的湿润面积。较高的子冷却下存在热毛细管对流的原因可能是由于FC-72是各种成分的混合物。 （C）2005 Elsevier Inc.保留所有权利。

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