• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.687-692
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• 2016

When turbochargers are applied to engines, the temperature of the engine becomes high, making the cooling of pistons very important. To solve this problem, an oil jet is used. The oil jet provides oil to the underside of piston for cooling. When an oil jet is used, oil pump size-up and oil cooler are needed because of the increased oil flow rate and higher oil temperature. On the other hand, these increase the friction torque of the engine. This study examined how much the friction torque of an engine increases by an oil jet, oil cooler, and oil pump size-up. In addition, the proportions of the friction torque of the engine increased by each part were measured by changing the engine assembly condition. At low speed, the oil pump and oil cooler had a larger effect on the friction torque than the other factors. At high speed, oil cooler had a larger effect than the other factors.

• The KSFM Journal of Fluid Machinery
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• v.15 no.4
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• pp.27-32
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• 2012

Gas turbines for an aircraft have the start and restart capabilities within their flight envelop. It is an important item for engine qualification and substantiated with the test. Experimental investigations were carried out to find the relation between the corrected torque and the corrected rotating speed of an air turbine starter in this study. A dedicated air supply system for the air turbine starter and a special device to measure the torque and the rotating speed of the air turbine starter were developed and installed at the altitude engine test facility in Korea Aerospace Research Institute. Experimental results show that the relations between the corrected torque and the corrected rotating speed of the air turbine starter are linear and the inlet temperature and pressure conditions for the air turbine starter were found out to provide minimum required torque for the engine qualification test at various altitude. The start and restart tests for the currently developing engine were successfully performed using this experimental results.

• Journal of Biosystems Engineering
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• v.16 no.1
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• pp.1-8
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• 1991

This study was carried out to evaluate indirect methods of engine torque measurement. Three indirect methods based on throttle valve opening, exhaust gas temperature and inlet air pressure were compared. The indirect method based on throttle valve opening appeared to be the most satisfactory in terms of accuracy and response time. The discrepancies between the direct method and the indirect method based on throttle valve opening in measuring engine torque were 2% on t he average.

• Journal of ILASS-Korea
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• v.13 no.2
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• pp.85-90
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• 2008

This paper presents the performance and emissions characteristics of a small spark-ignited gasoline engine. The engine used in this paper is a single cylinder, diaphragm carburetor, two-stroke, air-cooled 26cc SI engine for brush cutter. For the performance of the engine, RPM, torque, and fuel consumption were measured and HC, CO, and NOx measured for the emissions according to the change of the dynamometer load at wide open throttle (WOT) position. The results showed that the excess air ratio decreased and torque increased with increasing loads, the torque and brake specific fuel consumption were the optimum driving condition at the 7000 rpm, HC and CO emissions increased with increasing loads and with an decrease in excess air ratio over 7000 rpm.

• Journal of KSNVE
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• v.4 no.3
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• pp.319-325
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• 1994

The flucturation of the engine torque appears to be the major source of the torsional vibration of the automotive driveline. The reduction of this torsional vibration has become a significant problem, due to an increase in the flucturation of the torque of recent light weighted powered engines, along with the requirements of higher performance. The torsional vibration of the automotive driveline can be reduced by soothing the fluctuation by adjusting the torsional characteristics of the clutch-disc. Computer simulation of the engine- input gear train is a useful investigative tool on studying the torsional characteristics of the clutch-disc. In this paper, a dynamic model for the automotive driveline was developed, and the engine torque and drag torque of the model were evaluated withe experimental data. By executing a simulation using the model, it has become possible to obtain the clutch-disc torsional characteristics when the engine is idling and the clucth-disc torsional characteristics for reducing the torsional vibration has been suggested.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.6
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• pp.623-632
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• 2015

This study proposes a control strategy of the common rail pressure with a fuel injection limitation algorithm to reduce particulate matter (PM) emissions under transient states. The proposed control strategy consists of two parts: injection quantity limitation and rail pressure adaptation. The injection limitation algorithm determines the maximum allowable fuel injection quantity to avoid rich combustion under transient states. The fuel injection quantity is limited by predicting the burned gas rate after combustion; however, the reduced injection quantity leads to deterioration of engine torque. The common rail pressure adaptation strategy is designed to compensate for the reduced engine torque. An increase of the rail pressure under transient states contributes to enhancement of the engine torque as well as reduction of PM emissions by promoting atomization of the injected fuel. The proposed control strategy is validated through engine experiments. The rail pressure adaptation reduced the PM emission by 5-10% and enhanced the engine torque up to 2.5%.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.2
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• pp.428-436
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• 1998

A TCS slip control system improves acceleration capability and steerability on slippery roads through engine torgue and/or brake torque control. This research mainly deals with the engine control algorithm via the adjustment of the engine throttle angle. The following new control strategy is proposed and investigated ; the TCS slip controller whose input is the difference between the desired driving wheel speed corresponding to the optimum slip ratio and the actual speed yields the target engine torque and then estimates the throttle angle based on the engine performance curve. Various simulation and hardware-in-the-loop simulation have been carried out. The results show the proposed strategy may compensate for the inherent nonlinearity between variation of the throttle angle and variation of the engine torque and produce better performance than the previous strategies without the engine map, especially in the high speed region.

• Journal of Drive and Control
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• v.17 no.4
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• pp.141-151
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• 2020

The aim of this study was to analyze the safety factor of range-shift gear pairs on multi-purpose agricultural implement machinery for an optimal design of a transmission system. Gear-strengths such as bending and contact stress and safety factors were analyzed under three load conditions: an equivalent engine torque at plow tillage, a rated engine torque, and the maximum engine torque. Root and contact safety factor were calculated to be 3.88, 5.14, 2.24, 2.11, 2.21, 0.99 and 0.78, 0.94, 0.65, 0.68, 0.84, 0.85, respectively, under equivalent engine torque condition at the plow tillage. The root and contact safety factor were calculated to be 1.91, 2.53, 1.10, 1.04, 1.07, 0.48 and 0.55, 0.66, 0.46, 0.48, 0.59, 0.59, respectively, under rated engine torque condition. The root and contact safety factor were calculated to be 1.60, 2.11, 0.92, 0.87, 0.90, 0.40 and 0.51, 0.61, 0.42, 0.44, 0.54, 0.54, respectively, under the maximum engine torque condition. The multi-purpose agricultural implement machinery could be conducted under plow tillage operation. However, gear specifications for tooth surface need modification because the gear surface would be broken at all driving conditions as safety factors are lower than 1.

• Journal of the Korean Society of Propulsion Engineers
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• v.7 no.3
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• pp.53-60
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• 2003

A test stand was developed to measure static performance of a reciprocating engine on the ground, related to the small aircraft being developed by KARI. The test stand consists of an apparatus to install and operate a pusher-type propulsion system and a data acquisition system to process many performance parameters including engine torque and propeller thrust as well as monitoring of the engine operations. First, the performance data from the basic operation tests were compared with the original engine data so the capacity of the test stand was verified. Engine performance tests were carried out with various test conditions through three stages, and it was measured and analyzed that the manifold pressure, the torque, and the back pressure of the engine, and the static thrust of the propeller.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.6
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• pp.72-79
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• 1998

The goals of this research are to understand the regeneration characteristics in diesel particulate filter(DPF) using the cerium additive and throttling. The effects of throttling duration and spring tension of throttling valve were studied. Measurements were made on a 6 cylinder direct injection diesel engine and included pressure drop, filter inlet temperature, oxygen concentrations, and torque. The major conclusions of this work include; (i) the pressure drop is increased with increase of the engine load and the engine speed; (ii) the inlet temperature of the filter is reached $350^{\circ}C$ with certain engine operating condition which leads to sufficient temperature to regenerate with additive; and (iii) oxygen concentrations in the filter and engine torque during throttling operation are decreased by 2 percent and 36 percent, respectively, which are not critical about regeneration and vehicle operation.