• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.2
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• pp.181-188
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• 2016

It is known that reliability of liquid rocket engines depends on the design thrust, propellant, engine cycle, and hot firing test time. Previously, a method was developed for estimating reliability of a new engine by adjusting the design thrust and hot firing test time of reference engines where reference engines have the same propellant and engine cycle with the new engine. In this paper, we provide a procedure to predict the engine reliability when the new engine and the reference engine have different propellant and engine cycles. The proposed method is illustrated to estimate the engine reliability of the first stage of Korea Space Launch Vehicle II.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.5
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• pp.102-107
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• 2014

Because of high oil prices and emission gas problems, many governments tighten regulation of fuel economy and emission gas. For Passenger car, there are many researches for plug-in hybrid electric vehicles and they are being manufactured. On the other hand, there are few researches for plug-in hybrid electric bus that is heavy commercial vehicle. In this study, analysis of fuel economy for series plug-in hybrid electric bus according to engine operation strategy based on simulation is conducted. Forward simulator is developed using Autonomie. Engine operation strategies consist on constant engine operation strategy and engine on/off operation strategy. Considering the engine operation strategy, results of vehicle speed, engine operating points and fuel economy are obtained and analyzed. As a result, engine on/off operation strategy has more advantage than constant engine operation strategy in terms of fuel economy.

• The KSFM Journal of Fluid Machinery
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• v.17 no.5
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• pp.78-82
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• 2014

This paper describes a brief aerodynamic design procedure of multi-stage axial turbine. The design procedure was established including one dimensional scratch design, through flow analysis with empirical correlations, two dimensional airfoil design and three dimensional airfoil stacking. Detailed aerodynamic performance assessment was done with full three dimensional CFD method at the design and off design conditions to construct turbine performance map. With the present method, aerodynamic design procedure of 1st and 2nd stages of high pressure turbine for 10,000lbf class turbofan engine was introduced.

• Journal of Power System Engineering
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• v.21 no.3
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• pp.66-73
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• 2017

In order to identify the design parameters of a hydraulic engine mount with a nonlinear characteristics, an experimental method has been used generally. The method takes a considerable time and expense because of preparing an experimental apparatus, conducting a test, and analyzing results. Therefore, this paper presents a simple method to identify the design parameters of a cylindrical hydraulic engine mount, and optimize the design parameters. The physical model and mathematical equations of the mount were derived, and values of the design parameters of the mount were identified by optimization method with minimizing difference between the analytical results with the equations and the experimental results. This method is more simpler than the conventional experiment method and identify successfully the design parameters. In addition, the technique can optimize the design parameters of the mount to improves the isolation performance of the mount.

• Journal of Korea Game Society
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• v.1 no.1
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• pp.24-30
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• 2001

This paper is to consider on Engine-Technology & Engine-Design of the On-line Game for game production. This study will act as practical skill of the task for homemade game engine development which has competitive power internationally.

• Journal of ILASS-Korea
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• v.20 no.4
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• pp.247-253
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• 2015

Recently, the engine calibration technique has been much more complicated than that of the past engine case in order to satisfy the strict emission regulations. The current calibration method for the diesel engine which has an increasing market is both costly and time-consuming. New engine calibration method is required to develop for high-quality diesel engines with low cost and release it at the appropriate time. This study provides the optimal calibrating technique for complex engine systems using statistical modeling and numerical optimization. Firstly, it design a test plan based on Design of Experiments, a V-optimality methodology which is suitable looking for set-points, and determine the shape of test engine response. Secondly, it uses functions to make linear regression model for data analysis and optimization to fit the models of engines behavior. Finally, it generates the optimal calibrations obtained directly from empirical engine models using Grey Relational Analysis and compares the calibrations with data. This method can develop a process for systematically identifying the optimal balance of engine emissions.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.514-519
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• 2011

Recently, the interest in technologies for a highly efficient powertrain, i.e. a variable displacement engine or a light weight car body, to improve the fuel efficiency of automobile saving the environment has been increased. However this trend deteriorates NVH performance of a vehicle and the use of a conventional engine mounting system becomes unsatisfactory. In order to solve this dilemma, an active engine mounting system that could isolate or cancel out vibrations occurred at the powertrain was suggested. In this paper, In order to optimize the electromagnetic active engine mount performance, the actuator of the engine mount through FEM analysis and optimal design, noise and elastomer testing of the prototype through the optimal design of actuators for the electromagnetic active engine mount on the impact of the performance improvement is verified.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.144-152
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• 2011

In order to investigate the operation performance behaviors of the UAV's propulsion system to be operated long time in high altitude, the engine performance tests, which are simulated in the altitude engine test facility should be needed. If the test is performed in a existing altitude engine test facility, additional test apparatuses are required. Among them a proper design of the inlet and exhaust ducts that may directly affect the engine performance is very important. If the design is not adequate, the engine performance loss due to the flow behavior change and the pressure loss may be not similar to the real engine performance. In this work, firstly the engine inlet and exhaust ducts to be mounted to the existing altitude facility are modelled in 3D and its flow behaviors and pressure losses are analyzed using a commercial CFD tool, ANSYS's CFX, and the engine performance with the duct losses is calculated using the performance analysis program developed by C. Kong et al. Finally, the optimized inlet and exhaust ducts' configurations are proposed through the repeated analyses of various duct configurations.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.399-406
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• 2007

Structural vibrations of generator sets with medium speed diesel engine mainly come from the resonance between the excitations of engine and natural modes of system. The countermeasures to reduce the vibration or to avoid the resonance are fairly well known to workers. However these processes which are applied after the completion of system need much time consumption and additional cost. In this paper, the vibration measurement results collected for about 8 years were compiled as Database. Based on the database, the change of vibration was predicted with respect to variation of system such as engine type, generator weight, mount stiffness, and etc. As results of study, this paper presents the anti-vibration design procedures of newly composed generator sets using Database in the initial design stage and their effects.

• Journal of Aerospace System Engineering
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• v.14 no.6
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• pp.85-90
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• 2020

The infrared signature that is associated with an aircraft is mainly caused by heat released from the engine and the exhaust plume. In this study, a test-system was designed to observe the overall infrared signature characteristics of a turbofan engine during operation under ground running conditions and the infrared reduction features that result from different exhaust nozzle configurations. A test stand was designed for the 1400 lbf class turbofan engine that included a bell-mouth type intake, fuel supply system, a measurement system, and a data acquisition/control system. The design and verification of the test system were conducted so that the basic nozzle and various 2D nozzles could be applied to study the infrared signature produced by a turbofan engine exhaust.