단일 및 이중 파형 실린더 주위 열 유동장의 대형 와 모사

The present study investigates three-dimensional fluid flow and heat transfer around the single and double wavy cylinders at a Reynolds number of 3000 and Prandtl number of 0.7 by using large eddy simulation (LES). The spanwise wavelengths (λ/?D m ) for the single and double wavy cylinders are 6.06. The wave amplitude (a/?D m ) is fixed as the value of 0.152. For the purpose of the comparison, the smooth cylinder is also considered. The time averaged drag and fluctuating lift for the double wavy cylinder showed about 16% and 97% reduction, respectively compared to those for the smooth cylinder. Total surface-averaged Nusselt number for a smooth cylinder is larger than that of the single and double wavy cylinders. However, the local Nusselt number along the spanwise is strongly dependent on the spanwise geometric disturbance. The flow structures and isotherms distributions are analyzed to confirm the dependence of force and heat transfer coefficients on the wavy shape.