1999 年 65 巻 640 号 p. 4041-4048
An enhancement technique was developed for natural convection heat transfer from tall, vertical heated plate to water. Rectangular grid fins attached to the base plate were utilized as a heat transfer promoter. These grid fins redirect the high-temperature fluid ascending along the base plate toward the outside of the boundary layer and introduce the low-temperature ambient fluid toward the base plate instead. The heat transfer coefficients of thus-treated surfaces were measured and compared with a non-treated, fiat surface and a conventional surface with vertical straight fins. The highest performance was achieved for the experimental surfaces. In particular, the experimental surfaces with 5 mm-high, non-conducting grid fins and with 10 mm-high, conducting grid fins show 27% and 80% higher heat transfer coefficients compared to the turbulent heat transfer coefficients of the non-treated, fiat surface, respectively.