1. 제  목 : On the effect of relative curvature of a cylinder cooled by a circular impinging jet in crossflow

2. 연  사 : Prof. Tongbeum Kim (Wits University, Johannesburg)

3. 일  시 : 2012년 12월 18일 (화) 13:00-14:00

4. 장  소 : 301동 1409호

5. 내  용 : 
  This study is experimentally concerned with local cooling characteristics on a circular cylinder subject to a circular impinging jet in crossflow. Particular focus is placed on how the relative curvature of the cylinder to the circular jet diameter (D/Dj) affects convective heat transfer at the stagnation point and along the circumference of the cylinder. Results demonstrate that within potential core region, higher heat transfer rates at the stagnation point are achievable from cylinders having smaller diameters. In contrast, larger cylinders provide higher heat transfer rates at the stagnation point if immersed in fully developed region. Circumferentially, three distinctive relative curvatures are identified. First, for a small cylinder, flow separation causes a local minimum followed by a monotonic and gradual increase in local heat transfer when positioned either in the potential core or fully developed flow regions. Second, for an intermediate cylinder, the re-attachment of separated flow forms a separation bubble, presenting a second peak only when positioned within the potential core. On the other hand, local heat transfer is monotonically decreased from the stagnation point in the fully developed flow region. Third, for a large cylinder, transition from laminar to turbulent flows causes a second peak only within potential core whereas local heat transfer is monotonically decreased from the stagnation point in the fully developed flow region.
(sponsored by the Korea Ministry of Science and Technology via the South Korea-South Africa Research Center Program).

6. 연사약력 :
  Dr. Kim is Eskom Chair Professor of Mechanical Engineering in the School of Mechanical Engineering, University of the Witwatersrand, Johannesburg, South Africa (PhD (Cambridge), MSc (Georgia Tech), BEng (Kyung-Hee)). Dr. Kim received a Best Paper Award from UK National Heat Transfer Committee (09/2003) and an Outstanding Reviewer Award from the ASME Journal of Heat Transfer (11/2012).

7. 문  의 : 기계항공공학부 송성진 교수 (☏ 880-1701)