• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.7
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• pp.167-180
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• 1999

A control-oriented nonlinear dynamic engine model is developed to represent a spark ignited engine over a wide range of operating conditions. The model includes intake manifold dynamics,. fuel film dynamics, and engine rotational dynamics with transport delays inherent in the four stroke engine cycles. The model is mathematically compact enough to run in real time, and can be used as an embedded model within a control algorithm or an observer. The model is validated with engine-dynamometer experimental data, and can be used in design and development of a powertrain controller.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.7
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• pp.105-111
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• 2006

The aircraft engine is to generate thrust for the maneuver of aircraft and to provide the power to the related hydraulic system and electrical system. Since the power provided to the systems is extracted from the high pressure compressor of aircraft engine, the extracted power is called horsepower extraction (HPX). If the HPX provided from the engine is smaller than the HPX required from the related systems, there could be abnormal engine behavior, like engine rollback or stall. Analysis on comparing the required HPX and the engine HPX capability had been performed during the T/A-50 FSD (Full Scale Development) period. The analysis results make the engine schedule changed, and T/A-50 flight test has been performed with the changed engine schedule. The analysis results and changing the engine control schedule were verified to be valid with the flight test results.

• 대한공업교육학회지
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• v.33 no.2
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• pp.218-231
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• 2008

The purpose of this study was made for the pre-teacher of university to enhance understanding for the concept of engine performance and to provide information regarding engine performance in the institute of teacher educator. This study was carried out through engine performance experiment with The Cussons Engine Test Bed P8250, internal combustion engine, in order to analyze data quantitatively, and apply and verify factors of controlling engine performance. The main results of this study are as follows: First, power and brake horsepower increased linearly, and torque over the mid-speed as engine rps(revolution per second) decreased. Second, the change of torque and specific fuel consumption were able to be verified and the concept of engine performance was able to be understood. Third, the experimental values of brake horsepower and torque on engine performance showed the same tendency as theoretical values. Fourth, air/fuel ratio increased proportionally as engine speed increased.

• Journal of the Korean Institute of Gas
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• v.25 no.2
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• pp.34-41
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• 2021

In order to cope with the problems that may occur when the natural gas used in Korea becomes low in calories, the problems that may have to the domestic industrial gas equipment must be identified in advance, and based on this, countermeasures for efficient use of energy must be preceded. In this study, in order to solve the problem of deterioration of engine output performance and efficiency due to the introduction of low calorific gas when using a lean-burning natural gas engine that complies with the EURO-6 regulation, specific control plans and results based on the experiment are intended to be presented. In order to identify the improvement effect by the control variable represented by the ignition timing under the full load condition at the engine speed of 1,400 rpm and 550 Nm, 2,100 rpm, which is the engine speed at the rated operation condition, the thermal efficiency and exhaust gas characteristics were identified and optimized by changing the ignition timing for each gas fuel. In the case of pure methane, which shows the lowest value based on the torque under the full load condition, if the ignition timing is advanced by about 2 CAD from the reference ignition timing, the torque can be compensated without a large increase in NOx emission.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.10
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• pp.858-869
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• 2014

Most of the aerospace propulsion is based on the Brayton cycle, in which the combustion is held through the constant pressure process, but further improvement of performance by increasing compression ratio is challenged by mechanical limits. Detonation propulsions, regarded promising for high-speed propulsion for a lase decade, is more rigorously studied in these days as a game-changer for the improvement of thermodynamic efficiency of propulsion and power generation systems. Since, the additional compression by the strong shock of the detonation wave is considered increasing thermodynamics efficiency that is hardly achievable by the conventional compression systems. Present paper will give an introduction the latest technical trends on the Pulse Detonation Engines(PDEs) and the activities on the Pressure Gain Combustion (PGC) based on Constant Volume Combustion (CVC).

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.11
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• pp.978-983
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• 2015

A study on the speed limit and sizing of auxiliary fixed-wing of compound gyroplane was performed. The performance of the plane that uses the same rotor system and power of BO-105 helicopter was compared with that of BO-105 helicopter. The wing area which is used to compensate in lift, was calculated considering the aerodynamic characteristics and lift sharing ratio of the rotor. Achievable flight speeds were observed for two types of fuselage; BO-105 and streamlined bodies. The study showed that the autorotating rotor can share 1/2 of lift at high speed and the parasite power of compound gyroplane having streamlined body and small wing can be minimized, accordingly it can fly faster than helicopter with airspeed more than twice.

• Journal of Energy Engineering
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• v.20 no.2
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• pp.163-169
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• 2011

This research is to decide the possibility of using RM50(reformulated methanol fuel) without any modification of engine by the method of numerical analysis. Comparing the heat release rate, the difference among each fuel was decreased according to the increase of the engine speed, and the maximum heat release rate was higher in the order of RM50 and gasoline fuel. Also, this order corresponds to the order of burning speed. RM50 had the higher turbulent burning speed, and the curve of turbulent intensity was showed similar tendency to the curve of turbulent burning speed. RM50 had relatively high burning speed, short quenching length, high temperature in cylinder, so that it might increase NO emission, but owing to chemical reaction dynamics, it was decreased NO emission. Therefore, in order to predict the possibility of using RM50, it is needed to consider not only the temperature in cylinder by low heating value, but also combustion characteristics including burning speed.