2000 年 20 巻 2Supplement 号 p. 81-84
Research results pertinent to heat exchangers are available in existing literature and heat transfer text books. However, it was short of sufficient flow visualizations in louver fins because of the difficulty in its flow visualization. Flow visualization by means of the dye injection method and the laser Doppler velocimetry (LDV) was performed to disclose flow characteristics in louver fins. Three kinds of louver angles of θ=10°, 15° and 20° were tested. Flow patterns in each louver fins are visualized using the fluorescein dye illuminated a laser light sheet. The LDV data were used to calculate Reynolds stress distributions and power spectrum distributions. It is disclosed that flows in cases of θ =15° and 20° exhibit a distinctive periodic characteristics, and the Strouhal number is uniquely related to the Reynolds number.