• Journal of the Korean Society of Industry Convergence
• /
• v.7 no.2
• /
• pp.153-159
• /
• 2004

The purpose of this research is to investigate the performance of swirl combustion chamber diesel engine by changing the jet passage area, the depth and shape of the piston top cavity (main chamber). The performance of diesel engine with newly changed swirl combustion chamber was tested through the experimental conditions as engine speed, load and injection timing etc. The test results were compared and analyzed. And another purpose of this research is to make a new diesel engine that is satisfied fuel consumption and regulation value of exhaust gas. 1. The rate of fuel consumption was affected significantly by the jet passage area at the high speed and load than low speed and low load. The influence of jet passage large area was proven to decrease the rate of fuel consumption. 2. Smoke was affected significantly by the depth of the piston top cavity, but exhaust temperature and the rate of fuel consumption wasn't affected. The rate of fuel consumption was affected by changing injection timing. 3. The rate of fuel consumption, exhaust temperature and Smoke were affected significantly by the shape of the piston top cavity from rectangular to trapezoid. That is we have all high value. The exhaust smoke density and exhaust gas temperature depended sensitively on variation of the injection timing rather than the shape of the combustion chamber within the experimental conditions. 4. We made a new diesel engine that is satisfied design target values(sfc=190 g/hr, NOx + THC=6.0 g/KWh, PM=0.3 KWh), the rate of fuel consumption and emission standard etc., through changing injection timing at the maximum torque point and rated power point. Although we have a little high NOx value.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2012.10a
• /
• pp.93-99
• /
• 2012

This paper presents an optimal design of magnetorheological (MR) fluid based mount (MR mount in short) which can be applicable to vibration control of diesel engine of ship. In this work, a mixed - mode including squeeze mode, flow mode and shear mode is proposed and designed. In order to determine actuating damping force of MR mount required for efficient vibration control, excitation force from diesel engine is analyzed. In this analysis, a model of V-type engine is considered and the relationship between velocity and pressure of gas in torque of the piston is derived. Subsequently, by integrating the field-dependent rheological properties of commercially available MR fluid with the excitation force an appropriate size of MR mount is designed. In addition, in order to achieve maximum actuating force with geometric constraints design optimization is undertaken using ANSYS software. Through the magnetic density analysis, optimal design parameters such as bottom gap and radius of coil are determined.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.13 no.5
• /
• pp.127-133
• /
• 2005

Rotary swaging is one of the incremental forming process which is a chipless process using the reduction of cross-sections of bars, tubes and wires. The TDS(Tube Drive Shaft) of monobloc used in automotive has been developed by the rotary swaging process. The mechanical characteristics of swaged parts such as the hardness, thickness and roughness are also estimated to conduct experimental analyses of rotary swaging process with the materials of 34Mn5 Furthermore the change in the vibration mode of TDS due to design parameters, which are the tube length, diameter and thickness, has been investigated and analysed. The weight of the TDS product is smaller by about $12.8\%$ than that of SDS with the same performance. It could be evidently found that the TDS is designed to be much lighter than SDS (Solid Drive Shaft). This advantage might give some possibility to improve the NVH (Noise-Vibration-Harshness) characteristics. A maximum torque and a total number of torsional repetitions for the TDS is checked and measured to know the torsional intensity and fatigue strength through the static torsion test and torsional durability test, respectively. A total number of the torsional repetitions up to the fracture for the TDS is greater than 250,000 times.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.19 no.3
• /
• pp.65-72
• /
• 2011

In this study, the numbers, sizes of particles from a single cylinder direct injection spark-ignition (DISI) engine fuelled with gasoline and LPG are examined over a wide range of engine operating conditions. Tests are conducted with various engine loads (2~10bar of IMEP) and fuel injection pressures (60, 90, and 120 bar) at the engine speed of 1,500 rpm. Particles are sampled directly from the exhaust pipe using rotating disk thermodiluter. The size distributions are measured using a scanning mobility particle sizer (SMPS) and the particle number concentrations are measured using a condensation particle counter (CPC). The results show that maximum brake torque (MBT) timing for LPG fuel is less sensitive to engine load and its combustion stability is also better than that for gasoline fuel. The total particle number concentration for LPG was lower by a factor of 100 compared to the results of gasoline emission due to the good vaporization characteristic of LPG. Test result presents that LPG for direct injection spark ignition engine help the particle emission level to reduce.

• Polymer(Korea)
• /
• v.26 no.1
• /
• pp.71-79
• /
• 2002

RPP(maleic-anhydride grafted PP)and OPS(oxazoline grafted PS) do not react to each other, and thus show immiscibility. In this study, Nylons was added to RPP/OPS blend systems, as a reactive compatibilizer for enhancing the miscibility of the blends. When Nylon6 was added to the blends of RPP and OPS, RPP/Nylon6/OPS was produced. The effects of the molar ratio of Nylon6 on the RPP-Nylon6-OPS reaction were studied. Torque test and FT-IR analysis have been carried out to investigate the reaction of RPP/Nylon6/OPS system. The reaction torgue ratio and reaction efficiency show the maximum values at 1 : 0.66 : 1 and 1 : 1 : 1 (in moles) for RPP/Nylon6/OPS. In the RPP/Nylon6/OPS blends, their mechanical properties were changed with the molar ratio of Nylon6 and showed the highest value at molar ratio of 1.5. Physical properties and compatibility of RPP/Nylon6/OPS were compared with those of PP/Nylon6/OPS. Consequently, RPP/Nylon6/OPS plays a proper role as a reactive compatibilizer to the PP/PS blend system.

• Journal of Power System Engineering
• /
• v.18 no.2
• /
• pp.5-11
• /
• 2014

The purpose of this study is to investigate the specific characteristics of combustion and exhaust emissions on a 4-cylinder common rail diesel engine as EGR rate and the rate of blended bio-diesel was altered. Bio-diesel fuel which is a sort of alternative fuels can be adapted to diesel engine directly without modifying. This study was performed to 2000rpm of engine speed with torque 30Nm while EGR rate and the rate of blended bio-diesel was changed. Decreasing combustion pressure and increasing the rate of heat were occurred when we had changed the EGR rate on the 20% of bio-diesel blended diesel fuel. The maximum pressure of combustion and the IMEP became higher as the EGR rate and the rate of blended bio-diesel were changed. Exhaust gas temperature was increased the higher rate of the blended bio-diesel under the fixed EGR rate. However, it went down as the EGR rate increased. The amounts of CO and Soot were reduced with increasing the rate of the blended bio-diesel without changing EGR rate and raised with increasing of the EGR rate. On the fixed EGR rate, NOx was increased along with growing the rate of the bio-diesel. On the other hand, it was decreased while EGR rate were going up.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.34 no.10
• /
• pp.901-906
• /
• 2010

A three-dimensional flow simulation was performed to investigate the flow field in a wind farm on a complex terrain. The present study aims to examine the effects of mountainous terrain and turbine arrangement on the performance of wind power generation. A total of 49 wind turbines was modeled in the computational domain; detailed blade shape of the turbines was considered. Frozen rotor method was used to simulate the rotating operation. The torque acting on the turbine blades was calculated to evaluate the performance of the wind turbines. The numerical results showed details of the flow structure in the wind farm including the velocity deficit in the separated flow regions; this velocity deficit was due to the topographical effect. The effect of the wake induced by the upstream turbine on the performance of the downstream wind turbine could also be observed from the results. The methodology of the present study can be used for selecting future wind-farm sites and wind-turbine locations in a selected site to ensure maximum power generation.

• Elastomers and Composites
• /
• v.45 no.3
• /
• pp.223-229
• /
• 2010

We investigated the effects of processing geometry of silica-filled isobutylene-isoprene rubber (IIR) compounds on its mechanical properties and silica dispersion, using a two roll mill and an internal mixer (banbury mixer). The compound processed with the two roll mill showed the longer induction time ($t_2$), higher maximum torque ($T_{max}$), and better silica dispersion than the compound processed with the internal mixer; however, showed slightly the lower cure index ($t_{90}$). The mechanical properties (hardness, 300% modulus, tensile strength, elongation) of the compound processed with two roll mill were higher than compound done with the internal mixer.

• Korean Journal of Agricultural Science
• /
• v.37 no.2
• /
• pp.309-314
• /
• 2010

Bale is an operation of collecting livestock feed materials from field crop residue, and mechanization demand on the operation has been increased. Bailers imported from foreign countries such as Japan and European countries have been used, but those models showed improper performance in Korean situations. In recent years, a steel-roller type round baler attachable to medium size tractors(40 to 60 HP) for effective bale operation in Korea was developed. This study was conducted to evaluate field performance of the baler. For proper baling operation, engine speed was greater than 1,800rpm, average traction force and PTO torque were about 4kN and in a range of 380-671Nm, and maximum values were about 7kN and 3,000Nm, respectively. Performance evaluation tests for sudan grass, rice straw, and blue barley showed that field capacity was 0.59ha/h for blue barley and 0.99ha/h for sudan grass and rice straw. Bale weight, diameter, width, and bulk density were in ranges of 176.1~418.4kg, 1.07~1.12m, 1.02~1.04m, and 175.3~454.1kg/$m^3$. Noise sound level during the baling operation was 4dB greater than idle operation condition, which was considered to be ignorant.

• Journal of the Society of Naval Architects of Korea
• /
• v.34 no.1
• /
• pp.50-59
• /
• 1997

Shipbuilder checks the status of main engine and propeller operation before sea trial. Generally these tests are carried out at a quay during fitting out of the ship. For these tests the operator has to estimate the maximum RPM with permissible torque and thrust to ensure the safety of the mooring line and ship. In this paper, the propeller characteristics according to the draft variation for a moored ship is inveatigated. From these tests, it is shown that shaft submergence is a dominant parameter in the propeller performance at shallow shaft submergence and that the propeller performance is dependent upon the propeller RPM when the shaft submergence is kept unchanged. In this study, a simple formula of the required thrust for a given propeller shaft submergence and propeller RPM is derived. 1be propeller thrust, which is calculated by another formula in case of dtep draft, is compared with results of bollard pull test for FPSO.