Air flow field characteristics in a compact chamber system are indispensable for the efficient development of vehicle aerodynamic performance. In this study, air flow and velocity uniformity in the chamber system were numerically analyzed using the CFD method. Air flows at a uniform velocity from the outlet of the blower, passes fast through the heat exchanger with partial pressure difference, and then moves into the blower inlet. Overall pressure drop through the fan gradually increases with the flow rate. The uniformity varies along the test section, decreasing by 5-10% with distance from the nozzle. These predicted results can be widely used as basic conceptual design data for an efficient vehicle chamber system.

In this experiment, the engine (i30 FD) was fabricated and installed in front of the intake manifold of the gasoline engine of the 2010 1,600cc MPI(Multi Point Injection) 4-cylinder 16-valve DOHC(Double Over Head Camshaft) electronic control fuel injection system, and the plenum chamber was 150cc, 300cc, 4. The engine rotation speed was increased from 1000rpm to 3000rpm by 500rpm, and the pressure change and engine volume efficiency change of the air intake manifold runner were analyzed. In this study, the volume of air flowing into the cylinder was maximized through the stabilization of pressure vibration in the intake manifold runner part due to the engine operation condition and the volume change of the intake manifold plenum chamber, and the uniform distribution rate of the intake air was confirmed by minimizing the interference between the cylinders. It has in the purpose to analyze the flow characteristic at the intake manifold inside. It can apply to obtain the optimal design factor.

In order to improve indoor air quality of apartment, indoor ventilation system had to be installed in each unit, from 2006 in Korea. However, a duct which is connecting each room in ventilation system became a flanking path of sound. Sound which is generated in one room can easily transmitted into the adjacent room by the duct and speech privacy in apartment room can be seriously degraded. In this study, low noise duct system consisted of noise diffuser and multi drop chamber was developed and noise reduction performance was measured in mock-up system. Noise reduction performance of low noise duct system was compared with conventional duct system. From the result of measurement, it was found that noise diffuser reduce more than 10 dB in the range of 200 Hz and higher frequency band, also multi drop chamber was effective in 2000 HZ and higher frequency band. Noise reduction performance of low noise duct system is effective in the frequency range (from 300 Hz to 4000 Hz bands) of speech conversation.