Search Results

In order to extend the operability limit of the gasoline compression ignition (GCI) engine, as an avenue for low temperature combustion (LTC) regime, the effects of parametric variations of engine operating conditions on the performance of six-stroke GCI (6S-GCI) engine cycle are numerically investigated, using an in-house 3D CFD code coupled with high-fidelity physical sub-models along with the Chemkin library. The combustion and emissions were calculated using a skeletal chemical kinetics mechanism for a 14-component gasoline surrogate fuel. Authors’ previous study highlighted the effects of the variation of injection timing and split ratio on the overall performance of 6S-GCI engine and the unique mixing-controlled burning mode of the charge mixtures during the two additional strokes. As a continuing effort, the present study details the parametric studies of initial gas temperature, boost pressure, fuel injection pressure, compression ratio, and EGR ratio.

In this study, a series of tests have been carried out to evaluate the effects of the injection rate and timing on bsfc, NOx, and PM emissions in a heavy-duty diesel engine with TICS FIE system. Injection line pressure, cylinder pressure, NOx and smoke were measured with various injection times and injection rates. The injection rate was altered at a fixed injection timing, which could be realized either by changing the TICS setting time or by using different cam profiles. The injection time was varied by using TICS timing control function at a given setting time. A parametric study of the injection rate in in-line pump system was tried to correlate injection rate variations with combustion characteristics and emission. Two parameters, the injection pressure rising rate and the initially injected fuel quantity were introduced to characterize fuel injection.

Invisible Passenger-side Airbag (IPAB) door system must be designed with a weakened area such that the airbag will break through the Instrument Panel (IP) in the intended manner, with no flying debris at any temperature. At the same time, there must be no cracking or sharp edges at the head impact test (ECE 21.01). Needless to say, Head impact test must keep pace with the deployment test. In this paper, we suggested soft airbag door system that is integrally molded with a hard instrument panel by using Two-shot molding. First of all, we set up the design parameters of IPAB door for the optimal deployment and head impact performance by CAE analysis. And then we optimized the open-close time at each gate of the mold so that the soft and hard material could be integrally molded with the intended boundary. We could make the boundary of two materials more constant by controlling the open-close time of each gate with resin temperature sensor.

Due to technological evolutions and social demands, motor vehicles are requested to be enhanced in terms of occupant safety and comfort. As a result, many countries are reinforcing crash regulations and new car assessment programs. Automotive seats are essential parts for providing passenger safety and comfort and have become most important. Many automotive companies concentrate on optimization of the seat structure. This paper presents an overview of the recent evolution of the seat structures and gives a development procedure covering seat frame design, optimization and validation. Through the study, a competitive frame design is drawn as a case result and a design guideline and a standard development procedure is established

Acoustics comfort is a key point for the ground transportation market and in particular in the automotive area. A significant contributor to the noise levels in the cabin in the range 200Hz to 3000Hz is the HVAC (Heating, Ventilating, and Air Conditioning) system, consisting of sub-systems such as the air intake duct, thermal mixing unit, blower, ducts, and outlet vents. The noise produced by an HVAC system is mainly due to aeroacoustics mechanisms related to the flow fluctuations induced by the blower rotation. The structure borne noise related to the surface induced vibrations and to the noise transmission through the dash or plastic panels may also contribute but is not considered in this study. This study presents a digital approach for HVAC aeroacoustics noise predictions related to the ducts and outlet vents. In order to validate the numerical method flow and acoustics measurements are performed on production HVAC systems placed in an anechoic room.

Hard panel types of invisible passenger-side airbag (IPAB) door system must be designed with a weakened area such that the airbag will deploy through the Instrument Panel (IP) in the intended manner, with no flying debris at any required operating temperature. At the same time, there must be no cracking or sharp edges in the head impact test (ECE 21.01). If the advanced-airbag with the big difference between high and low deployment pressure ranges are applied to hard panel types of IPAB door system, it becomes more difficult to optimize the tearseam strength for satisfying deployment and head impact performance simultaneously. We introduced the ‘Operating Window’ idea from quality engineering to design the hard panel types of IPAB door applied to the advanced-airbag for optimal deployment and head impact performance. To accurately predict impact performance, it is important to characterize the strain rate.

In this paper, we deal with the automatic climate control for Recreational Vehicle (RV). The HVAC system used for RV was composed of front side and rear side. And, the HVAC system of front side differed from that of rear side in the characteristic of HVAC system. This system was economically optimized for automatic control over 2 separated zones. The development procedure of automatic climate controller was as follows. The first stage was to derive control equation from characteristic analysis of HVAC system and the structural characteristic of vehicle interior. In the second stage, the software (S/W) was designed and programmed to operate microprocessor which calculated previously mentioned equation. Finally, the hardware (H/W) design and building were performed to operate the HVAC system with the calculation results from microprocessor. The control performance of this automatic climate control algorithm and system was evaluated by experimental method.

Hyundai Motor Company has developed hydrogen fuel cell vehicles (FCV) based on its SUV, Santa Fe. As the hydrogen fuel cell power plant runs at near ambient pressure, parasitic loss due to its operation is fully minimized and the noise level of the air supply subsystem is extremely low. The Santa Fe FCV has been built to feature roomy passenger space and cargo capacity identical to that of a standard, gasoline-powered Santa Fe, because of its compact fuel cell power plant. In addition, lightweight aluminum body-components help to keep a power-to-weight ratio similar to that of a conventional SUV. Hyundai Motor Company, as a full member of California Fuel Cell Partnership, is now operating the Santa Fe FCV's on real roads in California. In this paper, the configuration and performance test results of the Santa Fe FCV will be described.

Invisible Passenger-side Airbag (IPAB) door systems must be designed with a weakened area such that the airbag will break through the Instrument Panel (IP) in the intended manner, with no flying debris at any temperature. A predictive Finite Element Analysis (FEA) was carried out to calculate the effects of varying design factors (the length and thickness of kink-hinge, tear-line type and temperature) on the IPAB-door opening. The impact performance of plastic parts was considered, because the mechanical properties of thermoplastic materials are strongly dependent on strain rate.

High pressure fuel injection systems, such as common rail (CR) systems and electronically-controlled unit injector (EUI) systems, have been widely applied to modern heavy duty diesel engines. They are shown to be very effective for achieving high power density with high fuel efficiency and low exhaust gas emissions. However, the increased peak combustion pressure gives additional structural stress and thermal load to engine structure. Thus, proper material selection and thermal analysis of engine components are essential in order to meet the durability requirements of heavy-duty diesel engines adopting a high pressure injection system. In this paper, thermal analysis of a 12.9 ℓ diesel engine with an EUI system was studied. Temperatures were measured on a cylinder head, a piston and a cylinder liner. A specially designed linkage system was used to measure the piston temperatures. A radio-tracer technique was also used to verify the rotation of piston rings.

Fuel tank in vehicle must hold the fuel in a stable way under any driving condition. However, the fuel tank might not conserve the fuel firmly in case a crack emerged while the fuel tank is exposed to different driving condition. Basically, when the engine is in purging at a normal ambient temperature before fuel boiling, the pressure inside the fuel tank decreases. However, the pressure inside a fuel tank increases while a vehicle is driven at extreme hot ambient temperature as fuel is boiling. This repetitive pressure change in the fuel tank comes with fuel tank’s physical expansion and shrink, which would cause a damage to the fuel tank. The main purpose of this research is to investigate the root cause of why fuel tank cracks at a fatigue point. We also aim to set up the method of how to test durability of the fuel tank in association with the pressure inside the tank.

Voice Recognition (VR) systems have become an integral part of the infotainment systems in the current automotive industry. However, its recognition rate is impacted by external factors such as vehicle cabin noise, road noise, and internal factors which are a function of the voice engine in the system itself. This paper analyzes the VR performance under the effect of two external factors, vehicle cabin noise and the speakers’ speech patterns based on gender. It also compares performance of mid-level sedans from different manufacturers.

A nano-sized PM and THC emission characteristics were investigated according to the fuel injection strategy such as a pressure and timing in the GDI engine. On the part-load condition, the particulate emissions exhibited a strong sensitivity to the injection timing. The fuel injection pressure also had a great association with the nano-particles and THC. A size of PM exhausted from the GDI engine located near 10nm on the part-load. In contrast, accumulation mode particles within 60 - 80nm mainly exhausted during the cold transient start phase. Increment of fuel injection pressure positively affected on the nano-particle and THC emissions during the start of the engine, as well.

In this project, phenomena in a SCR catalyst, such as heat transfer and catalytic reactions, are modeled numerically. The model is simplified to be integrated on an electronic control unit. The calibration process for this model has been developed, which is performed on gas bench and validated on a vehicle equipped with a Urea-SCR system and a Rapid Prototype Control Unit. With this simplified SCR reaction model, it is possible to estimate NH3 consumption and properly control the urea injection quantity with less calibration efforts.

Recently, flexible fuel vehicle (FFV) has been drawn great attention because of its response for immediate use as alternative fueled one. Hyundai FFV can be operated on arbitrary fuel mixtures between gasoline and M85 with the specially programmed electronic control unit (ECU) which can determine optimized fueling quantity and ignition timing as the methanol content by the signal from electrostatic type fuel sensor. In this paper, the results of various tests including engine performance, cold startability, durability and exhaust emission reduction have been described. Full load, cold mode durability tests and field trials have been carried out with some material changes and surface treatments in the lubricating parts and fuel system. But, more work on its durability improvement is still required.

This paper describes Hyundai's research and development work on a flexible fuel vehicle (FFV). The work on FFV has been conducted to evaluate its potential as an alternative to the conventional gasoline vehicle. Hyundai FFV described here can operate on M85, gasoline, or any of their combinations, in which the methanol concentration is measured by an electrostatic type fuel sensor. For that operation, a special FFV ECU has been developed and incorporated in the FFV. The characteristics affecting FFV operation, such as FFV ECU control strategy and injector flow rate, have been investigated and optimized by experiment. Various development tests have been performed in view of engine performance, durability, cold startability, and exhaust emissions reduction. The exhaust gas aftertreatment system being consisted of manifold type catalytic converter(MCC) and secondary air injection system has shown good emission reduction performance including formaldehyde emission.

This paper shows the cause and the solution to the uncommon noise which happens ½ order component of engine rpm when a vehicle with automatic transmission has an air conditioning load and “drive” range load on the engine. By measuring cylinder pressure, main bearing cap vibration, engine mount vibration, and interior noise simultaneously, the cause of the noise can be proved by analyzing and comparing the data. The cause of the uncommon noise is bending vibration of the crank shaft. To solve the problem, one can change the crank shaft dynamics by reducing the mass of the damper pulley.

This study presents engine test results of HMC's piston-ported 2-stroke gasoline engine. This single cylinder engine of 400cc displacement has featured in direct injection(DI) of fuel and external blower scavenging of air. Two different concepts of DI system were adopted, one is high pressure fuel injection(HPFI) system for solid fuel only and the other is low pressure air-assisted fuel injection(AAFI) system. Two kinds of engines with different scavenging intake port shapes and areas were tested to find the effect of scavenging port type on engine performance. Also tested were trends of BSFC, BSHC and BSCO versus fuel injection timing and engine speed with HPFI and AAFI, respectively. Power and boost pressure at full load and BSFC and BSHC at part load were tested.

Structure-occupant related method, which uses some structural analysis results for inputs of occupant simulation, has being used widely even if it is difficult to describe real crash precisely. The method is not proper to simulate complex situation such as an occupant behavior restrained with air bag in out-of-position impact. A structure-occupant integrated method is needed to analyze these sophisticated problems in the early stage of design. Therefore, Hyundai Motor Co. tried to develop the method, and the process is described in this paper. The integrated vehicle model includes Hybrid III dummy, air bag, seat belt and interior detail models. The interior detail models are instrument panel, knee bolsters, steering wheel and column, and seats. The part models were compared with the part test results and they were merged into larger models only if they passed correlation test.

To design an optimum engine intake system, a flow model for the intake manifold was developed by the method of characteristics. The flow in the intake manifold was one-dimensional, and finite difference equations were derived from the governing equations of flow. The thermodynamic properties inside a cylinder were found by the first law of thermodynamics, and the boundary conditions were formulated using a steady flow model. By comparing the calculated results with experimental data, the appropriate boundary conditions and convergence limits for a flow model were established. From this model, design variables for the intake system were investigated. The optimum manifold length became shorter when the engine speed were increased. The effect of intake valve timings on inlet air mass was also studied by this model. Advancing intake valve opening decreased inlet air mass slightly, and the optimum intake valve closing was found.