• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.3
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• pp.232-242
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• 1996

In this study, the simulation program for the prediction of volumetric efficiency of the internal combustion engine by the resonator has been developed, when the resonator is mounted on the intake system of 4-cycle SI engines for the improvement of volumetric efficiency. The experimental work has also been carried out for the verification of the program, and it is found that the result of calculation by the simulation program fits qualitatively well with that of experiment. To get the optimal mounting position of resonator on the intake system, the influence of the variation of dimensions of resonator such as neck length, volume and neck diameter were examined by the numerical calculation of the program in advance and the results were compared with the experiments. It is found that the position which is departed 150cm from plenum chamber is better than any other positions, and the average amount of the increase of volumetric efficiency is about 2∼3%

• Journal of Advanced Marine Engineering and Technology
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• v.21 no.3
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• pp.267-277
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• 1997

In this paper, heat conduction characteristics of the cylinder block of a small 3 - cylinder, 4¬stroke gasoline engine were analyzed using the 3 - dimensional finite element method. Based on the experimental data, the engine cycle simulation was carried out in order to obtain the heat transfer coefficient and the temperature of the gas and the mean heat transfer coefficient of the coolant. Heat transfer data of the gas, which were averaged with respect to exposure time to the wall, were taken as convective boundary conditions corresponding to the operating conditions to obtain the temperature fields of the block. Finally silicon nitride(Si3N4) was taken as the material of the block liner in order to investigate its temperature distribution characteristics and compare the results with the original ones.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.6
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• pp.10-20
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• 2022

The present study developed a design code for preburner of staged combustion cycle engines, which calculates preburnt gas at high-pressure oxidizer-rich conditions and predicts conjugate heat transfer and hydraulics of cryogenic fluid flow through cooling passages. It has been written based on the open-source library Cantera, into which this study has incorporated new source codes to predict correctly non-ideal thermodynamics and transport anomalies of the cryogenic fluid. For a preburner of 100 tonf-class booster engine currently under preliminary design, the present code demonstrated predictive capability and usability as a design code by comparing with CFD simulation.

• Transactions of the KSME C: Technology and Education
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• v.3 no.1
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• pp.15-21
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• 2015

In this paper a prediction method of GHP performance is proposed for increasing design accuracy. Two compressors with different capacity and 2311cc gas engine are used for prediction and the target capacity of GHP is 25HP. For predicting GHP performance at first the operation points are randomly selected and then as compared with compressor performance date and heat exchanger characteristic, more accurate operating points are decided through recursive calculation. Lastly engine performance date is used for calculating gas consumption volume. Predicting heating mode performance of GHP, evaporator is separated to the two section of absorbing heat in outdoor air and in engine. From the experimental results, it was found that the simulation model is good for the predicting GHP efficiency and the difference of predicted and measured efficiency is less than 5%.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.5
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• pp.660-667
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• 2000

In order to investigate the exhaust structure and secondary oxidation of unburned hydrocarbon (HC) in the exhaust port, concentrations of individual HC species were measured in exhaust process, the degree of oxidation were obtained. Using a solenoid-driven fast sampling system on single-cylinder research engine fueled with 94% propane, the profiles of unburned hydrocarbons (HCs) and non-fuel HCs with a propane fueled engine were obtained from several locations in the exhaust port during the exhaust process. The sampled gases were analyzed using a gas chromatography of HC species with 4 or lesser carbon atoms. The change of total HC concentration and HC fractions of major components through the exhaust port were discussed. The results showed that non-uniform distribution of HC concentration existed around the exhaust valve and changed with time, and that the exhaust gas exhibited nearly uniform concentration profile at port exit, which was due to mixing and oxidation. Also it could be known that bulk gas with relatively high HC concentration came out through the bottom of the exhaust valve. To estimate the mass-based degree of HC oxidation in the exhaust port from measured HC concentrations, a 3-zone diagnostic cycle simulation and plug flow modeling were used. The degree of oxidation ranged between 26 % and 36 % corresponding to the engine operation conditions.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.3
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• pp.304-311
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• 2014

In this study, to apply hydrogen energy to ship engine and to generate effective hydrogen production, we investigated the effects of high temperature $H_2SO_4$ feed rate and cooling water rate to pump parts with fixed frequency needed to reciprocate motion and a simulation was conducted at each condition. In the fixed frequency and cooling water inlet flow rate of 0.5 Hz and 3.9 kg/s, we changed the high temperature $H_2SO_4$ flow rate to 47.46 kg/s (it is 105 % of 45.2 kg/s), 49.72 kg/s (110 %), and 51.98 kg/s (115 %). Also, at 0.5 Hz and 45.2 kg/s of frequency and high temperature $H_2SO_4$ flow, the thermal hydraulic analysis was performed at the condition of 95 % (3.705 kg/s), 90 % (3.51 kg/s), and 85 % (3.315 kg/s). In overall simulation cases, the physical properties of materials are more influential to the temperature increase in the pump part rather than the changes on the feed rate of high temperature $H_2SO_4$ and cooling water. A continuous operation of pump was also capable even if the excess feed of high temperature $H_2SO_4$ of about 15 % or the less feed of cooling water of about 15 % were performed, respectively. When the increasing feed of high temperature $H_2SO_4$ of up to 5 %, 10 %, and 15 % were compared with base flow (45.2 kg/s), the deviation of time period rose to a certain temperature and ranged from 0 to 4.5 s in the same position (same material). In case of cooling water, the deviation of time period rose to a certain temperature and ranged from 0 to 5.9 s according to the decreasing feed changes of cooling water at 5 %, 10 %, and 15 % compared to a base flow (3.9 kg/s). Finally, the additional researches related to the two different materials (Teflon and STS for Pitch and End-plate), which are concerned about the effects of temperature changes to the parts contacting different materials, are needed, and we have a plan to conduct a follow-up study.