LARGE EDDY SIMULATION
ON HERT TRANSFER ENHANCEMENT OF INCLINED-CUT ELLIPSOIDAL VORTEX GENERATOR

WANG Jiansheng  LIU Zhiyi  ZHANG Jinfeng  TANG Junjie

(School of Mechanical Engineering, Tianjin University, Tianjin 300072)

Abstract: The flow and heat transfer characteristics of rectangle channel with inclined-cut ellipsoidal vortex generator are obtained with large eddy simulation. The instantaneous properties of velocity, temperature and pressure in channel are gained. The variety process of temperature, pressure and inducted vortex are revealed. Meantime, the heat transfer enhancement mechanism of vortex generator and flow structure are discussed. The turbulent model is used for verifying correctness of large eddy simulation in calculation of rectangle channel without vortex generator in the same calculation condition. The calculation result with two methods is consistent. The result of simulation indicates that the vortex can be induced by vortex generator. Furthermore, the stream-wise vortex induced by vortex generator pays more important role in heat transfer enhancement. Compared with the channel without inclined-cut ellipsoidal vortex generator in the same condition, the local heat transfer coefficient is enhanced from 64%~105%, and the average heat transfer coefficient is enhanced from 17%~36%. The enhancement of local heat transfer coefficient is occurred nearby the vortex generator. There is a consanguineous relationship between the fluid flow structure and status in near wall region with the local heat transfer.

Key words: Large eddy simulation  Inclined-cut ellipsoid  Vortex generator  Heat transfer enhancement

CLC No: TK124

国家自然科学基金资助项目(50476063). Received 20061016, received in revised form 20070509