Abstract

The results of laboratory experiments on determining the characteristics of convective turbulence over a heated metal surface at different heights and temperatures are presented. We used the high-speed thermography and a high-speed IR camera, which allowed imaging the temperature field of low-inertia paper targets hung up above the heated surface simultaneously throughout the vertical plane of the field of view of the camera. Based on fluctuations in the temperature field of the target surface, we determined the heat transfer coefficient, the convective flux intensity, the total flux, and the amount of heat generated during measurements at different heights above the surface. The energy spectra of convective turbulence are plotted under various turbulent conditions. The analysis of the turbulence spectra shows the presence of an inertial interval with a slope close to the 8/3 power law for all considered heights above the heated surface, temperatures, and turbulence conditions. Characteristics of convective turbulence we found can be used when testing different laser beam adaptive optics control systems, studying the propagation of vortex laser beams and combustion centers, which are also characterized by convective turbulence with further transition to atmospheric turbulence induced by the combustion energy.

中文翻译：

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加热表面对流湍流特性的高速热成像研究

摘要

介绍了确定不同高度和温度下加热金属表面对流湍流特征的实验室实验结果。我们使用高速热成像仪和高速红外相机，可以在相机视场的垂直平面上同时对悬挂在加热表面上方的低惯性纸目标的温度场进行成像。根据目标表面温度场的波动情况，确定了在表面上方不同高度测量时的传热系数、对流通量强度、总通量和产生的热量。对流湍流的能谱是在各种湍流条件下绘制的。湍流谱的分析表明，对于所有考虑的加热表面以上高度、温度和湍流条件，都存在惯性区间，其斜率接近 8/3 幂律。我们发现的对流湍流特征可以在测试不同的激光束自适应光学控制系统、研究涡旋激光束和燃烧中心的传播时使用，这些特征也具有对流湍流的特征，并进一步过渡到由燃烧能量引起的大气湍流。