직교류 팬 내부 유동의 큰 에디 모사 해석과 형상 최적화 및 사인파형 돌출부를 활용한 유동제어

다국어 초록 (Multilingual Abstract)

The flow characteristics in a cross-flow fan is investigated using large eddy simulation with an immersed boundary method. The Reynolds number of the fan is Re = 5,400 based on the blade chord length and the blade tip velocity at its outer radius. Due to the rotation of fan, an eccentric vortex locates at the lower right corner near a stabilizer, and the main flow passes by this vortex. A recirculation region at the inlet of the rearguide and flow separation on blade suction surfaces are also captured in the simulation. To alleviate these losses and increase the fan efficiency, we modify the casing geometry and apply sinusoidal protrusions on the leading edge of each blade inspired by humpback whale’s tubercle. To find optimum period and amplitude of the protrusion, we adopt the response surface methodology. The modified casing and optimum sinusoidal protrusions on each blade reduce the recirculation zone near the inflow region and vortex shedding inside the fan. Experimental results show that the fan with the optimum sinusoidal protrusions improves the fan efficiency by 5.2%, which is in good agreement with the LES. The fan with both the modified casing and optimum protrusions on each blade demonstrates higher efficiencies at all flow rates.

목차 (Table of Contents)

• Abstract
• 1. 서론
• 2. 수치해석 기법
• 3. 결과 및 토의
• 4. 결론
• 참고문헌