Library Subscription: Guest
Home Archives Officers Future meetings Assembly for International Heat Transfer Conferences

HEAT TRANSFER ENHANCEMENT OF INTERNAL PASSAGE USING DIMPLE/PROTRUSION

DOI: 10.1615/IHTC13.p17.240
10 pages

S. D. Hwang
Machinery, Metal & Construction Exam. Bureau, Korea Intellectual Property Office(KIPO), Daejeon, Korea

Hyung-Hee Cho
School of Mechanical Engineering, Yonsei University, Seoul 120 749, South Korea

Abstract

An experimental study was conducted to investigate the heat transfer and pressure drop of a rectangular channel with the dimpled and/or protruded walls. In the present study, three different roughened surfaces of dimpled, protruded and complex(dimple-protrusion) surface were tested. The dimples/protrusions were installed at both top and bottom walls of the rectangular channel. The local heat transfer coefficients on the dimpled/protruded walls were measured using a transient TLC(Thermocromic Liquid Crystal) technique. The friction factors of the rectangular channel with dimples/protrusions were obtained using pressure taps installed at the channel side wall. And the performance factors, which indicate the enhancement levels by both considerations of heat transfer enhancements and pressure loss increases were evaluated. As a result, high heat transfer region appeared at the rear side of the dimple due to the increased flow mixing on the dimpled surface. For the protruded surface, heat transfer was enhanced on the front side of the protrusion by the impingement effects of the flow induced by the horseshoe vortices. In case of complex geometry, dimple-protrusion, the compound effects of the dimple and protrusion occurred. The protrusion case showed the highest heat transfer enhancement among test cases. However, pressure loss increased. For the performance factor, the dimpled case shows the highest performance factor among test cases of dimpled, protruded and dimple-protrusion due to the its low pressure drop increase.

Download article Download MARC record Publication Ethics and Malpractice Recommend to my Librarian Bookmark this Page
 

IHTC Digital Library

Measurement of fluid temperature with an arrangement of three thermocouples