• 한국기계가공학회지
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• 제12권3호
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• pp.21-27
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• 2013

This study is investigated on flow analysis according to grill configuration of radiator. The stream of flow which pass through radiator grill in car body and the contour of pressure distribution are estimated by the basis. As the magnitude of resistance force which flow affects the car body is investigated so that the power reduction can be reduced. As the pressure inside radiator grill is assessed, more efficiency can be investigated in order that the flow rate inside car body can be increased. Model 2 has the most air resistance and model 1 has the least among model 1, 2 and 3. Model 1 has the most air flow rate at inside. There are model 3 and 2 simulated according to flow rate. As the curved surface at radiator grill configuration increases in number, air flow rate becomes distributed uniformly. By considering the effect on air resistance and air flow rate at radiator grill, model 3 becomes the most effective configuration.

• International Journal of Automotive Technology
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• 제8권5호
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• pp.659-666
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• 2007

In the present study, a numerical analysis of the three-dimensional heat transfer and fluid flow for a vehicle cooling system was developed. The flow field of the engine room between the grille and radiator was analyzed. The results show that, as the airflow inlet grille angle $\alpha$ is varied from $15^{\circ}$ to $-15^{\circ}$, the air flow rate compared with $\alpha=0^{\circ}$(horizontal) changes from -11.9% to +5.1%; while the heat flux from the radiator changes from -9.2% to +4.4%. When the airflow inlet bumper angle $\beta$ is varied from $-5^{\circ}$ to $+15^{\circ}$, the heat flux from the radiator compared with $\beta=0^{\circ}$(horizontal) increases up to +4.4%. When the airflow inlet grille angle $\alpha=-15^{\circ}$ and the bumper grill angle $\beta=+15^{\circ}$, the airflow rates and heat flux compared with($\alpha=0^{\circ}$, $\beta=0^{\circ}$) can be increased to +9.5% and +7.5%, respectively. The results indicate that the optimal angles for cooling efficiency are used.

• 소음진동
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• 제6권6호
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• pp.843-849
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• 1996

Locations and emission characteristics of noise source of motor vehicles are great important factors to control the road traffic noise in effective ways. From results of this study on emission characteristics of engine and exhaust noise, we could find that every noise emission of different kind of vehicles has smilar pattern. The main emission locations of engine noise for the front of vehicle became the space between the road surface and bottom of the body and radiator grill, and for the side of vehicle became the space between the road surface and bottom nearby the front wheel. In case of exhaust noise of passenger-car and light truck, all the highest sound intensity level located near surface of road. But it is hard to conclude the height of noise source of driving vehicles with only results of this study. So further studies are needed to check the emission characteristics of noise.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.119-123
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• 2013

We conduct the research for reducing aeroacoustic noise occurred when a vehicle operates in high speed situation without modifying the structural configuration such as deforming A-pillar's side curvature. We introduce PAU (Pneumatic Auxiliary Unit) which is a sort of air duct using intake air through radiator grill. According to our research, we can reduce overall noise levels around the surface of HSM (Hyundai Simplified Model). When a vehicleruns 100km/s, area-weighted acoustic power level (AWAPL) indicates 33dB without PAU. However with PAU, coverall AWAPL is decreased to 29dB which means we can improvesilentness approximately 12% compared to ordinary case. Moreover we conduct similar implementation to steering situation especially about yawing. In varioussituations, -10, 0, 10 degree of yawing, we observe 10% reduction in the upstream region of HSM but little increase in downstream region. It seems that inlet air overlap turbulent kinetic energy to surrounding flow. Even though downstream region's noise is louder than upstream region, overall AWAPL is still lower than conventional condition. We also apply this scheme to the real vehicle situation, then we get reasonable output which can support our research outputs.