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The sound barrier performance of elastomeric vehicle weather seals was investigated. Experiments were performed for one bulb seal specimen following a reverberation room method. The seal wall vibration was measured using a laser Doppler vibrometer. The acoustic pressure near the seal surface was measured simultaneously, allowing the sound intensities on both side of the seal, and the sound transmission loss to be evaluated. The vibration response of the bulb seal and its sound transmission loss were then computed using the finite element method. Model predictions for the same seal geometry were found to be in excellent agreement with the experimental data within the frequency range of interest, comprised between 500 Hz and 4000 Hz.

One dominant “wind noise” generating mechanism in road vehicles is the interaction between turbulent flows and flexible structures which include side glass windows. In this study, the effects of seal mechanical properties on the sound generated from flow-induced vibration of side glass windows were investigated. The primary goal was to assess the influence of seal support properties on the noise generated from a plate. Two different models to calculate the optimal support stiffness of the seal that minimizes the velocity response are presented. The results show that both the velocity response and the sound radiation are strongly influenced by dissipation of vibration energy at the edges. It is demonstrate that support tuning can yield significant noise and vibration reduction.

Sound transmission through door and window sealing systems is one important contributor to vehicle interior noise. The noise generation mechanism involves the vibration of the seal due to the unsteady wall pressures associated with the turbulent flow over the vehicle. For bulb seals, sound transmission through the seal is governed by the resonance of the seal membranes and the air cavity within the bulb (the so-called mass-air-mass resonance). The objective of this study was to develop a finite element (FE) model to predict the sound transmission loss of elastomeric bulb seals. The model was then exercized to perform a parametric study of the influence of seveal seal design parameters. The results suggest that the sound transmission loss increases as the membrane thicknesses and/or the separation distance between the two seal walls are increased. The addition of additional internal “webs” was found to have adverse effects on the sound barrier performance.

This paper describes the effects of diverse driving modes and vehicle component characteristics impact on fuel efficiency and emissions of light commercial vehicles. The AVL's vehicle and powertrain system level simulation tool (CRUISE) was adopted in this study. The main input data such as the fuel consumption & emission map were based on the experimental value and vehicle components characteristic data (full load characteristic curves, gear shifting position curves, torque conversion curve etc.) and basic specifications (gross weight, gear ratio, tire radius etc.) were used based on the database or suggested value. The test database for two diesel vehicles adopted whether prediction accuracy of simulation data were converged in acceptable range. These data had been acquired from the portable emission measurement system, the exhaust emission and operating conditions (engine speed, vehicle speed, pedal position etc.) were acquired at each time step.

The exhaust emission standards of vehicles using diesel fuel have been tightened for the prevention of air pollution. Therefore, this paper was carried out to study on the exhaust emission characteristics in the diesel engine with the Urea-SCR system according various urea contents rate. In order to analyze the emission characteristics, the diesel engine with six cylinders (7.6L) with the high pressure common-rail was used and it was applied to urea-SCR systems. In addition, the urea contents of six cases (0, 30, 32.5, 35, 37.5, 40%) were used to investigate the exhaust emission characteristics in the Urea-SCR system. To analyze the exhaust emission, the MEXA-7200D (Horiba) was used and FTIR (Horiba, MEXA-6000FT) was applied for the analysis of NH3. From this study, it is revealed that the NOx emission was significantly reduced as the urea content rate was increased until the 30%. However, the decreasing rate of NOx emission shows a slight steady reduction over the 30%.

Nations around the world have implemented various policies to control and manage air quality but VOCs (volatile organic compounds) aldehydes, and micro hazardous air pollutants are not subject to strict regulation compared to other exhaust emission sources of passenger cars. In this regarde, this study was conducted to evaluate how hazardous pollutants from passenger cars contribute to air pollution using gasoline and LPG fuels. For the study, a passenger car with GDI(Gasoline Direct Injection) and one with the LPI(LPG Port Injection) system were selected to evaluate the contribution rate of hazardous pollutants. Catalyst temperatures were measured for the prevention of emission variation in the process of stabilizing the catalyst and the modal data from the test mode was validated by using a chassis dynamometer (Horiba).

Under the present effort to decrease of air pollution, Electric Vehicles (EVs) are appeared and developed. EVs are running by using electrical energy resource by supporting of battery packs. The effect of air-conditioning has proven to be a serious problem to the point of battery depleting. Thus in the present study, effects of air conditioning (i.e., cooling and heating) on driving range were studied for various driving modes including UDDS, HWFET, and NEDC. The result shows that EV energy efficiency is opposing the usual trend of internal combustion engine vehicle's fuel consumption in highway driving mode than urban driving mode. In highway mode, EV energy efficiency and driving range also decease than urban driving mode. This status was influenced on motor characteristic which torque decrease in high speed rotating conditions and highway driving mode consist of constant speed velocity so it couldn't use the regenerative braking system effectively.

In the whole world, emission regulations for vehicles with internal combustion engine have been dramatically strengthened to reduce air pollutions of urban area. Recently, SULEV and EURO-6 emission standard were applied to the gasoline and diesel vehicles in Korea, respectively. Therefore, emission characteristics on passenger car using gasoline including HEV and diesel fuel according to the various test modes were conducted in this study. In order to this investigation, exhaust emission characteristics of gasoline and diesel vehicles were measured and analyzed by using chassis dynamometer (Chassis dynamometer 48˝compact 2WD, AVL) and emission analyzer (MEXA-7000 series, Horiba). Test vehicles were selected the 3 domestic models of a car in Korea. For analysis on emission characteristics according to driving cycles including certification mode, NEDC, FTP-75 and WLTP modes was applied. From these results, it can be shown that all test vehicle models meet the emission standard.

As the spread of electric vehicles increases, tests to measure the driving distance on a single charge, which takes about 6 hours or more to completely discharge the battery, have become necessary. There is also a need to conduct tests using indoor alternative modes, such as real driving emissions (RDE) tests, which take about two hours. These tests can be said to be very harsh working environments because they take long periods of time on chassis dynamometer, and sometimes low-temperature tests are also required. In this study, basic research was conducted to enable a driving robot to perform long-term automobile performance tests on behalf of humans indoors using a chassis dynamometer. The final development goal is to develop a driving pedal robot that has an automatic calibration function suitable for various vehicles and has a shorter installation time than driving robots in the existing market.