• Journal of Korean Society for Atmospheric Environment
• /
• v.12 no.3
• /
• pp.279-287
• /
• 1996

Pressure drop and fractional collection efficiency of automotive cabin air filters were examined to obtain the basic data for the development of high performance domestic cabin air filters. Pressure drop of MA-V100 was higher than that of VF-V100, and it increased with the air flow rate. VF-V100 had longer time to rise the critical pressure drop than that MA-V100 had. Total collection efficiency of MA-V100 for initial and dust loaded conditions was higher than that of VF-V100. Also, fractional collection efficiency of MA-V100 for the fine particles was higher than that of VF-V100. Particla size distribution for the minimum collection efficiency ranged from 0.02 $\mu$m to 0.04 $\mu$m for MA-V100 and it ranged from 0.02 $\mu$m to 0.15 $\mu$m for VF-V100.

• Journal of Aerospace System Engineering
• /
• v.2 no.2
• /
• pp.46-50
• /
• 2008

Aerodynamic characteristics, such as drag and lift, play an important role in automobile design under certain speed conditions. Such characteristics are essential to design an automobile since they are directly related to automobile's performance such as passenger safety and fuel consumption. There is a huge demand for the automobile to have safe performance at high speed. Reduction in drag is also important and it could lead to the solution of air flow induced noise and dust problems. The objective of this research is to find out the aerodynamic differences between conventional side mirror and a modified one using CFD. Although drag generated around a side mirror is only about 7% of the total drag when a car runs, it is very closely related to driver's field of vision and noise generation. CFD simulation of the flowfield around a car side-view mirror was performed using a commercial code; Gambit and FLUENT.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.14 no.3
• /
• pp.119-124
• /
• 2006

This paper deals with energy-saving effort in the hydraulic power steering system. Commonly, the hydraulic power steering systems are used for passenger cars and the reduction of pumping loss under non-steering condition is important to improve fuel economy. Experiments and simulations are performed simultaneously to examine the main factors to reduce the pumping loss-pressure loss and flow rate of the power steering systems. Fuel economy effect of the optimal design of power steering system is verified by vehicle test - more than 1% fuel consuming reduction is attained.

• Proceedings of the KSR Conference
• /
• 2003.10c
• /
• pp.358-362
• /
• 2003

Numerical simulation is conducted to clarify the heat transfer and fluid flow characteristics of HVAC(Heating, Ventilating and Air-Conditioning} for double-deck train. The HVAC system is installed under the roof of carbody. In the lay-out of HVAC system, air duct must be installed to supply air to 1st and 2nd floor respectively. The standard k-epsilon turbulent models and SIMPLEC algorithm based on finite volume method are used to solve the physical HVAC model. To assure convergence, QUICK scheme for momentum equation and the first order upwind scheme for turbulent equations are used. From the results of simulation, the temperature and velocity magnitude are also distributed uniformly in the interior of passenger car.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.12 no.6
• /
• pp.581-588
• /
• 2000

This paper describes the effect of vertical air circulation on the thermal environment in an airport passenger terminal with induced flow by jet fans. In comparing the level of thermal comfort at the breathing line of 1.5 m in height, the results from the two models with or without the vertical air circulation, show that the average PPD is 8% in the former and 23% in the latter, respectively. It is thought that vertical air circulation lends to improved thermal comfort for human in respect of ventilation in a large space.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.9 no.3
• /
• pp.201-209
• /
• 2001

Some passenger cars with sunroofs open at tilted positions experience reverse flows into cabin rooms and wind noises much louder compared to other cars. In this study, flows around open sunroofs are numerically studied with the variations of body leakage. The effects of body leakage on ventilation and wind noise of a sun roof are examined, in particular. Furthermore, flow visualization, pressure, and noise measured from wind tunnel and road tests are presented. The results show that too small body leakage results in poor performance of ventilation and generates high wind noise around a sunroof. It is therefore very important to secure an adequate body leakage from the early design stage to achieve better performance of a sunroof as well as passengers' comfort related to HVAC(Heating, Ventilation, and Airconditioning).

• Proceedings of the KIEE Conference
• /
• 2001.10a
• /
• pp.321-324
• /
• 2001

The accidents in a railway level crossing where passengers or vehicles pass on the track went through by the train with a inherent high rate on incidents lead to a vast economic damage on people and material resources. So, many protection equipments are placed on the railway crossing to prevent those kind of accidents. But there is a limit to control driver's rough activity, passenger's careless or an intentional accident. This study is trying to ensure the safety in railway crossing by providing the information on train's speed and expected passing time on the railroad to a road traffic control system or car driver. Additionally, this system has been studying the railway level crossing system concerning ITS to support harmonious traffic flow.

• Journal of Ocean Engineering and Technology
• /
• v.20 no.3 s.70
• /
• pp.24-36
• /
• 2006

This paper investigates wave loads of ships that suffer sinkage due to flood in a compartment caused by damage on the side of the hull. By analyzing ships with various sizesof damage opening, the influence of opening size on ship response is investigated. The motion of the damaged ship is analyzed by using the boundary element method, based on three-dimensional potential theory, considering hydrodynamic pressure in the flooded compartments. The shear forces, bending moments and torsional moments are calculated by the direct integration of the three dimensional hydrodynamic pressure on the outer and inner hulls. A RORO passenger ship with length of 174.8 m is considered in the numerical example, and results for wave loads are discussed.

• Journal of Navigation and Port Research
• /
• v.35 no.2
• /
• pp.131-136
• /
• 2011

As the faithful performance of ISPS of IMO, nowadays actually applicable an integrated safety and security system in and out of vessel should be organized in views of seafarers. Therefore, this paper is aimed to design a fundamental system for ship's integrated safety and security. The system of integrated grabbing will affect efficiently in any maritime field of material and human flow. Therefore this research will be expected to affect economical side by securing all the risk of maritime issues. In addition to the passenger ship and merchant vessel, it is applicable to other public and private vessels either. As a result of this paper, the system designed collecting various data through integrating the system including RFID reader, PIR sensor, and CMOS camera by putting an individual number into each unit that could be control at easy.

• Journal of Aerospace System Engineering
• /
• v.3 no.4
• /
• pp.1-6
• /
• 2009

Aerodynamic noise is becoming the major source of annoyance for modern cars recently and is caused by many different noise sources in a car. Appropriate CFD technologies, therefore, have been developed to resolve the noise problems related with aerodynamics. It is necessary for designers to fully understand the relationship between vehicle aerodynamics and wind noise acoustics. In this study, we simulate the flow fields around two different shapes of side mirror models of passenger car and analyze the noise phenomena around one side mirror model that has lower drag than the other model using Fluent 6.3.