컨테이너에 장착한 와류발생기의 공기역학적 영향에 관한 수치 해석 연구 = A Numerical Study on Aerodynamic Effect of Vortex Generator on a Container-Shaped Bluff Body

다국어 초록 (Multilingual Abstract)

The road-load power required to propel a vehicle at constant speed consists of the rolling resistance and aerodynamic drag force. The rolling resistance is proportional to the weight of the vehicle and the pressure drag force depends on frontal shape of the vehicle. For the lift force generated on a running vehicle, it should have positive effect on the vehicle to reduce the rolling resistance because the force compensate the weight of a heavy-duty truck.
In this study, a vortex generator is applied to a container-shaped bluff body to see its aerodynamic effect on the body. Airstream passing over the air-fence may possibly be accelerated due to vortex generated beneath the fence and due to the acceleration of airstream on the upper-side of the bluff body, negative pressure may possibly be set on and this phenomena will have positive effect on reducing the rolling resistance of the body. If the height of the generator is over the size of the boundary layer thickness formed due to the flow separation at the leading edge of the model container, an unexpected form or pressure drag will be produced. Therefore, the height of air-fence is very important parameter in the study. Five different sizes of air-fence were chosen and applied to the model container. Another important parameter is an initial location of the air-fence on the model container. The entrance length (LEL) of the air-fence was decided
From the result, it is found that the drag coefficient (CD) is decreased over 5.5% averaged with the air-fence that is 30 ~ 40cm in height and installed on 1.5m or further in LEN. For lift coefficient(CL), it is increased over 18.2% averaged with the air-fence set on 2.0m or further in LEL for all sizes of air-fence in height(HAF).