论文标题
受热液压受到热传递影响的空洞流的实验研究
Experimental study of cavitating flow influenced by heat transfer from heated hydrofoil
论文作者
论文摘要
这项研究通过实验研究了从加热的水翼对凹陷流量的热传递的影响，以了解高液液和高速条件下的蒸发现象。通过在用铜制造的NACA0015氢化材料中安装氮化铝加热器，在液压和主流之间产生了温度差。在Toohoku大学流体科学研究所的一条高温水腔隧道中进行了空气实验。通过改变主流速度和压力，即在860 W的固定加热器功率下，可以评估加热对空穴流动的影响。结果表明，从液压层影响的腔，腔，空腔方面和周期性方面，来自水电层影响的洞穴的热传递。由于较高的液压温度，对腔长的影响在较低的速度下变得更强。周期性的变化暗示加热效果减少了气蚀的不稳定。通过考虑从加热壁的热传递，提出了修改的空化数。通过考虑到接近加热液体的流体温度受主流和水翼之间的湍流对流传热的影响，从而得出了热校正项。校正后的空化数可以被视为一个参数，描述了统一表达中等温和加热病例中的空腔长度。
This study experimentally investigated the influence of heat transfer from a heated hydrofoil on cavitating flow to understand the evaporation phenomenon under high-heat-flux and high-speed conditions. A temperature difference was generated between the hydrofoil and mainstream by installing an aluminum nitride heater in a NACA0015 hydrofoil fabricated from copper. A cavitation experiment was performed in a high-temperature water cavitation tunnel at the Institute of Fluid Science, Tohoku University. The effect of heating on cavitating flow was evaluated by changing the mainstream velocity and pressure, namely the cavitation number, at a fixed heater power of 860 W. Results showed that the heat transfer from the hydrofoil affected cavitating flow in terms of the cavity length, cavity aspect, and periodicity. The effect on the cavity length became stronger at a lower velocity owing to a higher hydrofoil temperature. The variation in periodicity implied that the heating effect reduced the unsteadiness of cavitation. A modified cavitation number was proposed by considering the heat transfer from the heated wall. A thermal correction term was derived by considering that the fluid temperature close to the heated hydrofoil was affected by the turbulent convective heat transfer between the mainstream and hydrofoil. The corrected cavitation number can be considered as a parameter that describes the cavity length in the isothermal and heated cases in a unified expression.
