• Journal of the Korean Society of Visualization
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• v.9 no.3
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• pp.24-29
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• 2011

The improvement of climatic comfort is crucial not only for passenger comfort but also for driving safety. Therefore, a better understanding on the flow characteristics of ventilation flow inside the passenger compartment is essential. Most of the previous studies investigated the ventilation flow using Computational Fluid Dynamics (CFD) calculations or scale-down water-model experiments. In this study, the ventilation flow inside the passenger compartment of a real commercial automobile was investigated using a Particle Image Velocimetry (PIV) velocity field measurement technique. Under real operating conditions, the velocity fields were measured at several vertical planes for several ventilation modes. The experimental data obtained from this study can be used to understand the detailed flow characteristics in the passenger compartment of a real car and to validate numerical predictions.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.1
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• pp.120-128
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• 1997

The variations of the temperature field in a passenger compartment were measured by using a HSI true color image processing system and TLC(Thermochromic Liquid Crystal) solution. This temperature measurement technique was proved to be useful for analyzing the ventilation flow. The flow field in the passenger compartment was visualized using a particle streak method with pulsed laser light sheet. The temperature field and flow field in the passenger copartment were affected significantly by the ventilation mode. The panel-vent mode heating had shorter elapse time to reach a uniform temperature than the foot-vent mode under the same ventilation condition and nonuniformity inside the passenger compartment could be minimized effectively by using the bilevel heating mode. The temperature increase rate in the rear passenger compartment was iower than the front compartment, especially in the vicinity of the rear seat occupants' knee level.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.6
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• pp.178-185
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• 2001

This paper describes the correlation between the interior noise and the trunk wall vibration. Using the vibro-acoustic reciprocity, effect of the trunk wall vibration on the compartment noise is investigated on a medium size car. In the low frequency range, vehicle interior noise is dominated by several acoustic modes of the passenger compartment and the vibration modes of the surrounding shell parts. Especially, vibration of the trunk wall radiates sound and it is transferred through holes on the package tray into the passenger compartment. This paper experimentally reveals that sound can be well produced at some particular vibration modes of the trunk lid and it strongly influences the compartment noise through package tray holes. Contributions of the trunk walls to the interior noise are estimated by measuring the acoustic-structural transfer function, based on the vibro-acoustical reciprocity theorem.

• Journal of Industrial Technology
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• v.22 no.A
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• pp.43-48
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• 2002

Acoustic modes of a vehicle compartment dominate the noise characteristics of the vehicle system in the low frequency range. Vehicle compartments have head liner and air gap of proper thickness to mount a interior lamp, as well as to have a good sound insulation and absorption performance. This study estimates the acoustic modal property of the medium size passenger car by experiment and by finite element analysis and also, investigates the effect of the head liner on the acoustic mode of the passenger compartment to obtain useful information for low noise compartment design.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.607-611
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• 2000

Acoustic modal property of the vehicle passenger compartment is a very important factor which dominates vehicle interior noise in the low frequency range. In most real cars, trunk noise often transfers into the passenger compartment since the two cavities are acoustically coupled. This study identifies the major coupling path by examining the variation of the coupled acoustic modal frequencies and modes. An 1/2 size acryl compartment model is designed and manufactured for the measurement and analysis of coupled acoustic modes. Experimental result shows that package tray contributes to the coupling much more than the back seat and hole size of the package tray is an important design factor to control low frequency acoustic modes in the coupled system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.176-181
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• 2000

Acoustic modal characteristics are investigated on the passenger compartment and trunk coupled system. One-dimensional theoretical model is proposed and the validity of the model is verified by experiment on a simplified compartment model. The theoretical model identifies the occurrence of a new low frequency compartment mode, which does not exist in the uncoupled passenger compartment. The effect of the hole size on the compartment modes is analytically and experimentally examined.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.618-622
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• 2000

This paper describes the correlation between the interior noise and the trunk wall vibration. Using the vibro-acoustic reciprocity, effect of the trunk wall vibration on the compartment noise is investigated on a medium size car. In the low frequency range, vehicle interior noise is dominated by several acoustic modes of the passenger compartment and the vibration modes of the surrounding shell parts. Especially, vibration of the trunk wall radiates sound and it is transferred through holes on the package tray into the passenger compartment. This paper experimentally reveals that sound can be well produced at some particular vibration modes of the trunk lid and it strongly influences the compartment noise through package tray holes. Contributions of the trunk walls to the interior noise are estimated by measuring the acoustic-structural transfer function, based on the vibro-acoustical reciprocity theorem.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.1
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• pp.60-66
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• 1999

This study is to develop design sensitivity analysis method based on continuum theory for the actual buckling load of vehicle passenger compartment with respect to sizing design variables. For nonlinear structural analysis, both geometric and material nonlinear effects are considered. The total Lagrangian formulation for incremental equilibrium analysis and one-point linear eigenvalue problem for buckling analysis are utilized. Numerical methods are presented to evaluate design sensitivity expressions, using structural analysis results from FEM code. Optical design of vehicle passenger compartment with buckling constraint solved using Gradient projection method.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.667-670
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• 2002

Vehicle's airtight integrity is a very important factor that greatly affects passenger's habitability. However, when a door is closed, the pressure in the passenger compartment increases due to the vehicle's airtight integrity. That pressurizes the eardrums of the passenger, and makes passenger unpleasant. Thus, in this study, the configurations of air ventilation hasve been investigated to reduce pressure in the passenger compartment. Truck cab is utilized to measure the pressure in the passenger compartment. Various kinds of air ventilations are considered to find out optimized pressure in truck cab when a door is closed.

• Journal of the Korean Society of Visualization
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• v.7 no.1
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• pp.3-8
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• 2009

Most vehicles have a heating, ventilating and air conditioning (HVAC) device to control the thermal condition and to make comfortable environment in the passenger compartment. The improvement of ventilation flow inside the passenger compartment is crucial for providing comfortable environment. For this, better understanding on the variation of flow characteristics of ventilation air inside the passenger compartment with respect to various ventilation modes is strongly required. Most previous studies on the ventilation flow in a car cabin were carried out using computational fluid dynamics (CFD) analysis or scale-down water-model experiments. In this study, whole ventilation flow discharged from the air vent of a real passenger car was measured using a special PIV (particle image velocimetry) system for large-size FOV (field of view). Under real recirculation ventilation condition, the spatial distributions of stream-wise turbulence intensity and mean velocity were measured in the vortical panel-duct center plane under the panel ventilation mode. These experimental data would be useful for understanding the detailed flow structure of real ventilation flow and validating numerical predictions.