Soo-Jin Jeong

• Ph.D.
• Executive Principal Researcher at Korea Automotive Technology Institute

This study develops and validates a three-dimensional CFD model for a 12 L large-bore active-type pre-chamber spark-ignition (PCSI) engine fueled by natural gas. The model incorporates an advanced Extended Coherent Flamelet Model (ECFM-3Z) with a tuned stretch factor to capture complex turbulence–flame interactions, flame propagation, and pollutant...

This study develops and validates a three-dimensional CFD model for a 12-liter large-bore active-type pre-chamber spark-ignition (PCSI) engine fueled by natural gas. The model incorporates an advanced Extended Coherent Flamelet Model (ECFM-3Z) with a tuned stretch factor to capture complex turbulence–flame interactions, flame propagation, and pollu...

This study examines the dynamic fluid behavior of a PWM-controlled Solenoid-Operated Gas Admission Valve (SOGAV) for large-bore CNG engines using 3D Computational Fluid Dynamics (CFD) simulations with dynamic mesh techniques. The research focuses on the influence of orifice geometry variations in the multi-hole restrictor and pressure differentials...

This study examines the dynamic fluid behavior of a PWM-controlled Solenoid-Operated Gas Admission Valve (SOGAV) for large-bore CNG engines using 3D CFD simulations with dynam-ic mesh techniques. The research focuses on the influence of orifice geometry variations in the multi-hole restrictor and pressure differentials between the inlet and outlet...

The growing demand to reduce emissions of pollutants and CO2 from internal combustion engines has led to a critical need for the development of ultra-lean burn engines that can maintain combustion stability while mitigating the risk of knock. One of the most effective techniques is the pre-chamber spark-ignition (PCSI) system, where the primary com...

The recent demand for reducing pollutant and CO2 emissions from internal combustion engines has created an urgent need for the development of ultra-lean burn engines that ensure combus-tion stability and reducing knocking tendency. One of the most promising methods is the Pre-chamber Spark Ignition (PCSI) system, where a jet of high-energy reactive...

In order to maintain the performance of a fuel cell vehicle, it is essential to maintain a constant temperature of the stack. Therefore, it is very important to distribute the optimal coolant flow rate to each major component under very diverse and rapidly changing dynamic operating conditions. The part responsible for this is a five-way electric c...

The aim of this study is to investigate transient dynamic flow characteristics of the fluid flow through 5-way electric coolant valve (PCCV : Penta-Control Coolant Valve). To achieve this goal, the present paper attempts the three-dimensional dynamic simulation of the fluid flow through the valve using a commercial CFD solver with moving mesh techn...

Recently, in order to minimize air pollution and noise during the operation of the special vehicle, the hybrid E-PTO (Electric Power Take-Off) system has been developed. In this study, a three-dimensional multi-phase CFD model has been developed that can simulate the cooling performance inside a oil-cooled PMSM motor for the E-PTO. Using the CFD mo...

Accurate evaluation of thermo-fluid dynamic characteristics in tanks is critically important for designing liquid hydrogen tanks for small-scale hydrogen liquefiers to minimize heat leakage into the liquid and ullage. Due to the high costs, most future liquid hydrogen storage tank designs will have to rely on predictive computational models for min...

Accurate evaluation of thermo-fluid dynamic characteristics in tank are critically important for designing liquid hydrogen tank of small-scale hydrogen liquefier to minimize heat in-leak into the liquid and ullage. Due to the huge cost, most future liquid hydrogen storage tank designs will have to rely on predictive computational models for storage...

The ever growing importance of an effective thermal management will certainly benefit the pursuit of a more efficient vehicle. For this reason, enhanced electrical-based cooling system functionalities are in high demand. In order to meet such demand, an integrated coolant control valve(ICCV), which will replace the former wax thermostat, has been d...

It is important for turbocharged GDI(T-GDI) engines to reduce oil mist in the blow-by gas to prevent LSPI and turbocharged oil coking. Therefore, this study has developed a high efficiency cylinder, head-integrated oil mist separator by using a compact fleece, impactor-type oil mist separator system to ensure adequate oil mist separation performanc...

Advanced engine cooling systems reflect a variable coolant temperature because they can decrease the hydrodynamic frictional losses of lubricated engine parts in light duty conditions. To raise the operating temperature of passenger cars to a constant level safely, and thus optimize combustion and all accompanying factors, a new thermostat technolo...

One of the major Engine thermal management system(TMS) strategy for improving fuel economy is operating the engine in high temperatures. Therefore, this work performed numerical and experimental study to examine the effect of several different STOs(Starting Temperature of Opening) of wax-thermostat, ranging from 85℃ to 105℃ of gasoline engine on fu...

In this work, graphene platelets were introduced into wax in an automotive electronic controlled thermostat for the purpose of enhancing its thermal-conductive property and improving response performance. Graphene content ranging from 10 % to 20% was added into and mixed with the wax to investigate the effect of graphene amounts on the performance...

.Abstract − The efficient steam drum should be required to reduce carbon oxide emissions and heat recovery in oxygen converter hood system. However, steam generation is limited to the time of the oxygen blowing period, which is intermittent or cyclical in operation of steel-making process. Thus, steam drum should be optimized for an effective steam...

The efficient steam drum should be required to reduce carbon oxide emissions and heat recovery in oxygen converter hood system. However, steam generation is limited to the time of the oxygen blowing period, which is intermittent or cyclical in operation of steel-making process. Thus, steam drum should be optimized for an effective steam generation...

From now on, in order to meet more stringer diesel emission standard, diesel vehicle should be equipped with emission after-treatment devices as NOx reduction catalyst and particulate filters. Urea-SCR is being developed as the most efficient method of reducing NOx emissions in the after-treatment devices of diesel engines, and recent studies have...

The common-rail injectors are the most critical component of the CRDI diesel engines that dominantly affect engine performances through high pressure injection with exact control. Thus, from now on the advanced combustion technologies for common-rail diesel injection engine require high performance fuel injectors. Accordingly, the previous studies...

DME(Di-methly Ether) is a potential second generation diesel fuel for compression ignition engines due to the extremely low level of particulate matter emissions, And easy to liquefy at room temperature. For this reason, the research and development of DME vehicles were introduced worldwide, but it has never been attempted advanced injection strate...

This experimental work described the effect of flow control valve type on the performance of wobble plate type fuel pump for the stable DME fuel supply. In order to study this, different four types of flow control valves (ITV,SCV, IMV and MPROP) were installed on the wobble plate fuel pump, and fuel flow rate, torque, and temperature variation of p...

Corresponding author: sjjeong@katech.re.kr DME(Di-methly Ether) is a potential second generation diesel fuel for compression ignition engines due to the extremely low level of particulate matter emissions, And easy to liquefy at room temperature. For this reason, the research and development of DME vehicles were introduced worldwide, but it has nev...

DME (Di-Methyl Ether) is synthetic product that is produced through dehydration of methanol or a direct synthesis from syngas. And it is able to save fossil fuel and reduce pollutants of emission such as PM and CO2. In spite of its advantages it is difficult to design DME fuelled engine system because DME fuel may cause to severely generate cavitat...

Spray visualization and computer simulation of a DME injector have been conducted to investigate the enlarged injection hole diameter effect. To increase the reliability of the computational result, simulation results have been compared with the visualization test results, and the behaviors of a DME spray under various high-pressure and -temperatur...

The main and side reactions of the three selective catalytic reduction (SCR) reactions with ammonia over a vanadium-based catalyst have been investigated using synthetic gas mixtures in the temperature range of 170{\sim}590^{\circ}C. The three SCR reactions are standard SCR with pure NO, fast SCR with an equimolar mixture of NO and NO_2, and NO_2 S...

In this study, the trucks(2.9-liter) have been developed to use DME as fuel, and performance test of the vehicle's DME engine, power, emissions, fuel economy and vehicle aspects was conducted. For experiments, the fuel system(common-rail injectors and high-pressure pump included) and the engine control logic was developed, and ECU mapping was perfo...

We investigated the DME spray characteristics about varied ambient pressure and fuel injection pressure using the common rail fuel injection system when the nozzle holes diameter is varied. The common rail fuel injection system and fuel cooling system were used since DME has compressibility and vaporization at atmospheric temperature. The fuel inje...

To improve the conversion over a SCR (selective catalytic reduction) catalyst, the DOC (diesel oxidation catalyst) is usually placed upstream of the SCR catalyst to enhance the fast SCR reaction () using equimolar amounts of NO and . Here, a ratio of above 50% should be avoided, because the reaction with only () is slower than the standard SCR reac...

A typical cooling system of an engine relies on a water pump that circulates the coolant through the system. The pump is typically driven by the crankshaft through a mechanical link with engine starting. In order to reduce the friction and warm-up time of an engine, the clutch-type water pump (CWP) was applied in 2.0 liter diesel vehicle. The clutc...

It is investigated of the DME spray characteristics about varied ambient pressure and fuel injection pressure using the common rail fuel injection system when the nozzle holes diameter is varied. The common rail fuel injection system and fuel cooling system is used since DME has compressibility and vaporization in atmospheric temperature. The fuel...

The -SCR characteristics of over a V-based catalyst are experimentally examined over a wide range of operating conditions, i.e., and , with a simulated diesel exhaust containing , NO, , , , and . The influences of the space velocity and oxygen concentration on the standard-SCR reaction are analyzed, and it is shown that the low space velocity and h...

Die slide injection marvelously reduces the cost and time in processing plastic products because they can simplify the conventional process through eliminating additional process. However, this process must be resolved some defects like whitening, resin infiltration, blowhole, resin overflow, etc. In this study, the process parameters of the inject...

A typical cooling system of an engine relies on a water pump that circulates the coolant through the system. The pump is typically driven by the crankshaft through a mechanical link with engine starting. In order to reduce the friction and warm-up time of an engine, the clutch-type water pump (CWP) was applied in 2.0 liter diesel vehicle. The clutc...

The selective catalytic reduction (SCR) system is a highly-effective aftertreatment device for NOx reduction of diesel engines. Generally, the ammonia (NH 3) was generated from reaction mechanism of SCR in the SCR system using the liquid urea as the reluctant. Therefore, the precise urea dosing control is a very important key for NOx and NH 3 slip...

We investigated the efficacy of fuel stratification in a pre-mixture of di-methyl ether (DME) and n-Butane, which have different auto-ignition characteristics, for reducing the pressure rise rate (PRR) of homogeneous charge compression ignition (HCCI) engines. A new chemical reaction model was created by mixing DME and n-Butane and compared to exis...

A minimization of the maximum diesel particulate filter (DPF) wall temperature and fast light-off during regeneration are targets for a high durability of the DPF and a high efficiency of soot regeneration. A one-channel numerical model has been adopted in order to predict the transient thermal response of the DPF. The effect of the ratio of the le...

A one-dimensional monolithic catalyst model was used to evaluate the effect of space between two bricks on the thermal efficiency of a dual-monolithic catalytic converter with a Palladium-only (Pd-only) catalyst and a Palladium=Rhodium (Pd=Rh) catalyst butted together, and which are, in turn, mounted on a commercial vehicle equipped with a 2-L, fou...

In practical applications, monolithic catalytic converters are operated at non-isothermal conditions. In this case, the active metal distribution along the length of the converter may influence its performance. Indeed, better conversions can be achieved by controlling the distribution of the same quantity of active material. In this study, we used...

The working of diesel particulate filters(DPF) needs to periodically burn soot that has been accumulated during loading of the DPF. The prediction of the relation between an uniformity of gas velocity and soot regeneration efficiency with simulations helps to make design decisions and to shorten the development process. This work presents a compreh...

This paper has been focused on the development of integrated automotive muffler system to meet getting more stringent sound quality target. Typically, muffler system consists of resonator and main muffler. The many varieties in exhaust pipe routing and the flexibility in muffler design make it possible to design an exhaust system to deliver tailpip...

The use of a diesel particulate filter (DPF) in a diesel aftertreatment system has proven to be an effective and efficient method for removing particulate matter (PM) in order to meet more stringent emission regulations without hurting engine performance. One of the favorable PM regeneration technologies is the NO2-assisted regeneration method due...

A modeling approach to predict the performance of commercial diesel oxidation catalyst (DOC) is presented in this study. Prior to completing this prediction, the conversion behavior of DOC as previously published was re-evaluated with a verification of the present numerical model. To calibrate and validate the model adopted in this study, steady-st...

As the management of fuel efficiency becomes globally reinforced in attempts to find an environment-friendly vehicle that will operate against global warming, the interest in and the demand for the type of vehicle with a high-efficiency diesel engine using light oil. However, it also emits a greater amount of PM (particulate matter) and NOx than em...

Urea-SCR, the selective catalytic reduction using urea as reducing agent, has been investigated for about 10 years in detail and today is a well established technique for deNOx of stationary diesel engines. In the case of the SCR-catalyst a non-uniform velocity and profile will cause an inhomogeneous conversion of the reducing agent , resulting in...

In recent years, several methods to regenerate PM (Particulate Material) from DPF (Diesel Particulate Filter) have been developed to meet getting more stringent emission regulations. A favorable technology is NO2-assisted regeneration method due to the capability of continuous regeneration of PM under much lower temperature than that of thermal reg...

We used a one-dimensional monolithic catalyst model to predict the transient thermal and conversion characteristics of a dual monolithic catalytic converter with a Palladium only (Pd-only) catalyst and a Palladium/Rhodium (Pd/Rh) catalyst. Prior to the numerical investigation of the dual-catalyst converter, we modified the pre-exponential factor an...

Developing a mathematical model to predict the abnormal flow characteristics that are produced by obstructive sleep apnea is an important step in learning the pathophysiology of the obstructive sleep apnea (OSA) disease. The present study provides detailed calculations of flow in the pharyngeal airway of a patient with obstructive sleep apnea. To a...

Optimization of the urea dosing system to maximize deNOx performance and to minimize NH 3 slip during load changes is one of the main challenges for the mobile application of the urea–SCR (selective catalytic re-duction) system. A mobile SCR system is restricted to a short distance between the engine exhaust and the cat-alyst entrance. Therefore, i...

The use of an Exhaust Gas Recirculation(EGR) for a diesel engine with variable geometry turbocharger(VGT) has confronted how to obtain the amount of EGR for NOx reduction requirement at wide operating range and less side effect. Through a combined effort of modeling(wave action simulation) and experiment, an investigation into the effect of EGR are...

The static and dynamic behaviour of VGT and EGR systems has a significant impact on overall engine performance, fuel economy and exhaust emissions. This is because they define the state and composition of the air charge entering the engine. This work focused on the effect of the aperture ratio of VGT and EGR on the emission and flow characteristics...

To use computer simulations to describe the role of fluid dynamics in the human upper airway. The model was constructed using raw data from three-dimensional (3-D) computed tomogram (CT) images of an obstructive sleep apnea (OSA) patient. Using Bionix software (CantiBio Inc., Suwon, Korea), the CT data in DICOM format was transformed into an anatom...

A four-stroke four-cylinder turbocharged diesel engine can be fitted with various types exhaust system. In this paper, the impacts of exhaust system design on scavenging performance and wave action characteristic during valve overlap are investigated by using one-dimensional gas dynamic code. This work shows that a huge reflected exhaust pressure w...

The minimization of maximum DPF wall temperature and the fast Light-off during regeneration are the targets for the high durability of the DPF system and the high efficiency of regeneration. In order to predict transient thermal response of DPF, one-channel numerical modeling has been adopted. The effect of the ratio of length to diameter(L/D), cel...

The cooling effect of a mobile phone using PCM(Phase Change Material) module has been numerically investigated. A transient three-dimensional numerical analysis of heat and fluid flow with natural convection is performed in this study. Governing conservation equations for mass, momentum and energy are solved by an implicit finite volume method. An...

In the past few years, considerable efforts have been directed towards the further development of Urea-SCR(selective catalytic reduction) technique for diesel-driven vehicle. Although urea possesses considerable advantages over Ammonia(NH3) in terms of toxicity and handling, its necessary decomposition into Ammonia and carbon dioxide complicates th...

The engine-out flow is highly transient and hot, and may place tremendous thermal and inertial loads on a closed-coupled catalyst. Therefore, time-dependent and detailed flow and thermal field simulation may be crucial. The aim of this study is to develop combined chemical reaction and multidimensional fluid dynamic mathematical model and to study...

The work presented in this paper concerns the aerodynamic characteristics and compression wave generated in a tunnel when a high speed train enters it. A large number of solutions have been proposed to reduce the amplitude of the pressure gradient in tunnels and some of the most efficient solutions consist of (a) addition ofa blind hood, (b) additi...

In this study, a numerical analysis of the deposition of gallium arsenide from TMGa and arsine in a horizontal MOCVD reactor is performed to investigate the effect of inlet diffuser shape of reactor on the flow and deposition characteristics. The effects of two geometric parameters (diffuser angle, diffuser shape) on the growth rate, growth rate un...

The optimal design of an auto-catalyst needs a good compromise between the pressure drop and flow uniformity in the monolith. One of the effective methods to achieve this goal is to use the concept of a radially variable cell density. But this method has not been examined with respect to its usefulness in terms of chemical behavior and light-off pe...

In the present work, the effect of a flow maldistribution on the thermal and conversion response of a monolithic catalytic converter is investigated. To achieve this goal, a combined chemical reaction and multidimensional fluid dynamic mathematical model has been developed. The present results show that flow uniformity within the monolith brick has...

In the present work, the effect of a flow maldistribution on the thermal and conversion response of a monolithic catalytic converter is investigated. To achieve this goal, a combined chemical reaction and multidimensional fluid dynamic mathematical model has been developed. The present results show that flow uniformity within the monolith brick has...

Mathematical modeling of three-way catalytic converter (3WCC) operation is used increasingly in the optimization of automobile converter systems. But almost all of previous computational models were based on "adiabatic one-channel" approach with the reaction kinetics computations, which is useful and efficient in predicting real-world performance o...

Light-off catalysts are often used to minimize cold-start emissions. The improved coldstart performance of light-off catalysts (LOCs) needs the optimal design in terms of flow distribution, geometric surface areas (GSA), precious metal (PM) loading, cell density and space velocity (SV). In this study these influential factors are numerically invest...

A study is made of the flow and conversion characteristics of the pulsating flow of an automotive catalytic converter. To investigate the unsteady flow effects of a dual monolithic catalytic converter of double-flow type, a numerical methodology coupled with wave action simulation based on gas dynamic theory is developed. The flow inside the conver...

HC and CO emissions during the cold start contribute the majority of the total emissions in the legislated driving cycles. Therefore, in order to minimize the cold-start emissions, the fast light-off techniques have been developed and presented in the literature. One of the most encouraging strategies for reducing start-up emissions is to place the...

Light-off catalyst has been used for minimization of cold-start emissions. Improved cold-start performance of light-off catalyst needs the optimal design in terms of flow distribution, geometric surface area, precious metal loading, cell density and space velocity. In this study, these influential factors are numerically investigated using integrat...

A theoretical and experimental study of three-dimensional steady and unsteady compressible non-reacting flow inside double flow of monolith catalytic converter system attatched to 6-cylinder engine with two Y type junctions at inlet exhaust pipes was performed for the achievement of performance improvements, reduction of light-off time, and longer...