PIV Measurements of Ventilation Flow inside the Passenger Compartment of a real passenger Car

이진평(Jin Pyung Lee),김학림(Hak Lim Kim),이상준(Sang Joon Lee) 한국가시화정보학회 2009 한국가시화정보학회 학술발표대회 논문집 Vol.2009 No.11

Most vehicles have a heating, ventilating and air conditioning (HVAC) device to control the thermal condition and make comfortable environment in a passenger compartment. The improvement of comfortability of the passenger compartment is crucial for creating comfortable environment and securing driving safety. For this, better understanding on the variation of flow characteristics of ventilation air inside the passenger compartment with respect to the ventilation condition is strongly required. Most previous studies on the ventilation flow, were carried out using computational fluid dynamics (CFD) method or scaledown water-model experiments. In this study, by using a particle image velocimetry (PIV) velocity measurement technique, the ventilation flow inside the passenger compartment of a real passenger car with HVAC system was measured and analyzed experimentally. With varying ventilation mode, the velocity fields inside the vehicle interior were measured at several vertical planes along the spanwise direction. These experimental data will be used for understanding the detailed flow structures and validating numerical predictions.

거대 화상용 PIV 시스템을 이용한 실차 내부 공기벤트 토출흐름의 속도장 측정 연구

이진평(Jin Pyung Lee),김학림(Hak Lim Kim),이상준(Sang Joon Lee) 한국가시화정보학회 2009 한국가시화정보학회지 Vol.7 No.1

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 largesize FOV (field of view). Under real recirculation ventilation condition, the spatial distributions of streamwise turbulence intensity and mean velocity were measured in the vertical 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.

제상모드에 대한 실차 내부 환기유동의 정량적 가시화 연구

이진평(Jin Pyung Lee),이상준(Sang Joon Lee) 한국가시화정보학회 2010 한국가시화정보학회지 Vol.8 No.2

Thermal comfort inside a passenger car has been receiving large attention in automobile industries. Especially, the performance of windshield defroster is important in the design of a car to ensure passenger comport and safety. Thereby, better understanding on the ventilation flow along the vehicle windshield is essential to evaluate the performance of windshield defroster. However, most previous studies dealt with the defrost flow using CFD (computational fluid dynamics) calculations or scale-down model experiments. In this study, a real commercial automobile was used to investigate the flow discharged from the vehicle defroster and the ventilation flow along the windshield using a PIV velocity field measurement technique. The experimental data would be useful to understand the flow characteristics in detail and also call be used to validate numerical predictions.

PIV를 이용한 실차 내부 환기유동의 정량적 속도장 측정

이진평(Jin Pyung Lee),이상준(Sang Joon Lee) 한국가시화정보학회 2011 한국가시화정보학회지 Vol.9 No.3

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.

Ventilation Flow along the Vehicle Windshield of a Real Passenger Car

이진평(Jin Pyung Lee),이상준(Sang Joon Lee) 한국가시화정보학회 2010 한국가시화정보학회 학술발표대회 논문집 Vol.2010 No.11

Thermal comfort inside a passenger car has been receiving large attention in automobile industries. Especially, the performance of windshield defroster is important in the design of a car to ensure passenger comfort and safety. Thereby, better understanding on the ventilation flow along the vehicle windshield is essential to evaluate the performance of windshield defroster in real situation. However, most previous studies dealt with the defrost flow using CFD (computational fluid dynamics) calculations or scale-down model experiments. In this study, a real commercial automobile was used to investigate the flow discharged from the vehicle defroster and the ventilation flow along the windshield using a PIV velocity field measurement technique. These experimental data would be useful to understand the flow characteristics in detail and also could be used to validate numerical predictions.

In vivo Trial of a Micro-angiographic PIV Technique for Hemodynamic Studies

Sang Joon Lee(이상준),Guk Bae Kim(김국배),Jin Pyung Lee(이진평) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.5

The synchrotron X-ray PIV technique using a coherent synchrotron X-ray as a light source for PIV velocity field measurements has been utilized to investigate blood flows without any contrast materials or tracer particles. For applying this X-ray PIV method for in-vivo tests, bio-compatible hollow microcapsules were developed. The hollow inner space of the tracer, filled with air, plays a key role to induce epoch-making contrast enhancement based on X-ray refraction mechanism. Using the fabricated hollow microcapsules, we tried to apply the X-ray PIV method to the in-vivo visualization of blood flows in a rat. The hollow microcapsules used exclusively would make the synchrotron X-ray PIV method be more powerful and generally used in various flow imaging researches as a new-concept micro-angiographic PIV diagnosis method.

정현파 형상 노즐 평면제트의 유동구조에 관한 실험적 연구

김학림(Hak Lim Kim),이진평(Jin Pyung Lee),이상준(Sang Joon Lee) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11

The flow structure of a turbulent plane jet issuing from a sinusoidal nozzle exit configuration was investigated using a hot-wire anemometry and PIV velocity field measurement. The sinusoidal upper and lower plates were arranged to have in-phase and 180° out-of-phase configurations. Hot-wire anemometry was employed to measure the vertical velocity profiles and PIV measurements were conducted to investigate flow structure in the horizontal planes. Mean velocity and turbulence intensity profiles in vertical planes at three spanwise location (0, λ/4 and λ/2) were measured at several downstream locations(x/h = 0.5~6). The jet velocity at the nozzle exit was U<SUB>j</SUB> = 3 m/s (Re<SUB>D</SUB> = 5000). For the case of in-phase nozzle, the length of potential core exhibit negligible difference at three transverse locations. On the other hand, the 180° out-of-phase nozzle configuration has a maximum difference of 30% in the length of potential core. The spatial distribution of turbulent intensity also show significant difference for the out-of-phase nozzle configuration. Flow visualization results seem to support the presence of non-symmetric vortical structure, yielding the large different vortex structure between the nozzle configurations. For the case of in-phase nozzle configuration, the jet flow propagated from the edge of wave pattern nozzle to the jet center and peculiar flow structure was appeared.

X 선 유동영상용 조영 입자의 합성, 분석 및 응용

안성숙(Sungsook Ahn),정성용(Sung Yong Jung),이진평(Jin Pyung Lee),김혜구(Hae Koo Kim),이상준(Sang Joon Lee) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11

For a dynamic X-ray visual imaging, the contrast agents in particle forms are developed in micro- and nano-scales. A water-soluble contrast agent is encapsulated into biocompatible polymeric microparticles or gold is designed into functionalized nanoparticles. The fabricated polymeric microparticles are controlled in terms of the size and the encapsulation efficiency of the X-ray contrast agent. The behaviors of the particles in the solution are described by hydrodynamic size (DSUB>H</SUB>) and zeta-potential (ζ-potential). The surface of the gold nanoparticles is modified with acidic, basic, hydrophilic and hydrophobic monolayer. The microscopic structures of the gold nanoparticle aggregates are determined by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and zone-plate X-ray microscopy. The designed particles are excellent X-ray imaging tracers which enable the dynamic study in the various fluid flows including biological systems.