The study investigates a jet impingement cooling process of a cylindrical geometry relevant for electric and electronic applications. The applied two-color detection technique enables a simultaneous determination of film temperature and film thickness. For this purpose, the heat transfer oil Marlotherm LH was doped with the temperature-sensitive fluorescence tracer nile red. The temperature determination was realized by suitable band pass filters. Preliminary spectral investigations were carried out in terms of varying dye concentration, temperature and film thickness. At high dye concentrations (up to 37.5 mg/L), reabsorption effects lead to a spectral shift toward higher wavelengths with increasing film thickness. Low dye concentrations (0.29 mg/L, 0.59 mg/L) show no film thickness dependent spectral shift. A film temperature investigation at low dye concentration showed no bias of the intensity ratio due to film thickness, i.e., no additional spectral shift toward lower wavelengths was observed. The investigations on the jet impingement setup revealed an increasing film temperature and decreasing film thickness with increasing solid temperature. The average film temperature increases with increasing solid temperature from 298 (solid temperature 298 K) to 308 K (solid temperature 398 K). At higher solid temperatures, the film temperature increases with distance to the stagnation zone. The average film thickness decreases with increasing solid temperature from 0.24 to 0.17 mm. At high solid temperatures, the film temperature increased with radial distance to the stagnation zone. This behavior is caused by the increasing temperature gradient with increasing solid temperature and decreasing viscosity with increasing film temperature.

该研究研究了与电气和电子应用相关的圆柱形几何形状的射流冲击冷却过程。采用的双色检测技术可以同时测定薄膜温度和薄膜厚度。为此，导热油 Marlotherm LH 中掺杂了温度敏感荧光示踪剂尼罗红。通过合适的带通滤波器实现温度测定。根据不同的染料浓度、温度和薄膜厚度进行了初步光谱研究。在高染料浓度（高达 37.5 mg/L）下，随着膜厚度的增加，重吸收效应会导致光谱向更高波长移动。低染料浓度（0.29 mg/L、0.59 mg/L）没有表现出与薄膜厚度相关的光谱偏移。低染料浓度下的膜温度研究表明，强度比没有因膜厚度而产生偏差，即没有观察到额外的光谱向较低波长移动。对射流冲击装置的研究表明，随着固体温度的升高，薄膜温度升高，薄膜厚度减小。平均薄膜温度随着固体温度的增加而增加，从298（固体温度298 K）到308 K（固体温度398 K）。在较高的固体温度下，薄膜温度随着距停滞区的距离而增加。随着固体温度的升高，平均膜厚度从 0.24 毫米减小到 0.17 毫米。在高固体温度下，薄膜温度随着与停滞区的径向距离的增加而增加。这种行为是由于随着固体温度的升高而增加的温度梯度以及随着薄膜温度的升高而降低的粘度引起的。