TURBULENCE HEAT TRANSFER ENHANCEMENT TECHNIQUE FOR SQUARE DUCT WITH HIGH ASPECT RATIO

종횡비가 큰 사각 덕트내 난류 유동의 대류 열전달 증진 기술에 대한 연구

In this study, we develop a method to achieve heat transfer enhancement inside a square duct with high aspect ratio without changing any inner structures. Especially, a method to lower the possible maximum temperature is suggested if constant heat flux is provided to single surface of square duct. Knowing the fact that heat transfer rate is inversely proportional to flow area, we proposed tapered channel concept which uses narrower gap toward the flow exit where the maximum temperature is expected. To maintain equivalent power consumption, inlet section has been enlarged. To verify the proposed concept, experimental tests have been performed.