2002 Volume 45 Issue 4 Pages 910-916
This paper proposes a novel technique that can augment heat transfer but nevertheless can reduce pressure-loss in a fin-tube heat exchanger with circular tubes in a relatively low Reynolds number flow, by deploying a single row of the delta winglet type of vortex generators beside the front row of the three-row tube bundles in an in-line arrangement. The winglets are placed with a heretofore-unused orientation for the purpose of augmentation of heat transfer. This orientation is called as “common flow up” configuration. The proposed device causes a significant separation delay, reduces form drag, and removes the zone of poor heat transfer from the near-wake of the tube. This enhancement strategy has been successfully verified by experiments in the proposed configuration. In the in-line tube bundle with three rows, the heat transfer was augmented by 10% to 20%, and yet the pressure loss was reduced by 8% to 15% for the Reynolds number (based on two times channel height) ranging from 350 to 2100, when the present winglets were built in a single front row.
JSME international journal. Ser. 1, Solid mechanics, strength of materials
JSME international journal. Ser. A, Mechanics and material engineering
JSME international journal. Ser. 3, Vibration, control engineering, engineering for industry
JSME international journal. Ser. C, Dynamics, control, robotics, design and manufacturing
JSME International Journal Series A Solid Mechanics and Material Engineering