• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2014.10a
• /
• pp.515-517
• /
• 2014

엔진 부조(engine hesitation)의 원인을 추적함에 있어 가장 효과적인 점검방법 중의 하나가 엔진파워 밸런스(engine power balance)를 점검하는 것이다. 본 연구에서는 공회전 상태에서 4개의 실린더 폭발의 압력 편차로 인한 엔진 부조를 점검하기 위해 엔진 파워 밸런스를 점검하는 방법을 사용한다. 엔진의 부조는 네 개의 실린더의 회전 밸런스가 틀어졌기 때문이므로 실린더의 회전 밸런스 정보를 수집 분석하는 방법이 필요하다. 본 연구에서는 실린더의 엔진 회전수를 계산하기 위해 OBD-II와 무선 시스템인 블루투스 모듈을 이용하여 실시간으로 CKP 센서 정보를 수집하는 방법과 밸런스가 틀어진 실린더를 찾는 알고리즘을 제시하여 엔진 파워 밸런스를 조절 관리하는 시스템을 스마트 폰에 구현하고자한다.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.19 no.5
• /
• pp.62-70
• /
• 2015

A liquid rocket engine system can cause rapid pressure and temperature variations during the startup period. Thus the startup analysis is required to reduce time and expense for successful development of liquid rocket engine through the startup prediction. In this study, a startup analysis simulator is developed for a staged combustion cycle engine powerpack. This simulator calculates propellant flow rates using pressure and flow rate balances. In addition, a rotational speed of turbopump is obtained as a function of time by mathematical modeling. A startup analysis result shows that the time to reach a steady-state and a rotational speed at the steady-state are 1.3 sec and 27,500 rpm, respectively. Moreover it can indicate proper startup sequences for stable operation.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2007.04a
• /
• pp.135-140
• /
• 2007

An analysis has been conducted of the optimal condition to maximize the specific impulse for a liquid rocket engine with film cooling. The present engine performance has been compared with the published conceptual design to be verified satisfactorily accurate. The optimal combination of film coolant flow rate and the regenerative cooling capacity has been found for maximum specific impulse. The optimal fuel pump pressure increases and the optimal film coolant flow decreases for a larger thrust engine. Higher turbine inlet temperature increases both the fuel pump pressure and the film coolant flow rate as the optimal condition. The coking temperature has the same qualitative effect as the turbine inlet temperature.

• Journal of Power System Engineering
• /
• v.12 no.1
• /
• pp.41-46
• /
• 2008

The primary objective of this study is to truly understand exciting forces of the in-line 4 cylinders engine. Exciting forces of the engine apply a source of the vehicle NVH(Noise, Vibration, Harshness). To understand exciting forces, first was governed theoretical equations for single cylinder engine. And this theoretical equations was programming using MATLAB software. To compare theoretical analysis value, was applied MSC.ADAMS software. To determined the specification of engine(2,000cc, in-line 4) was applied ADAMS/Engine module. And this specification for engine was applied ADAMS/View and MATLAB software. The geometry model for ADAMS/View analysis was produced by the 3-D design modeling software. After imported 3-D model, each rigid body was jointed suitable. Under idle speed for engine, was analysed. The results of analysis are fairly well agreed with those of three analysis method. Using MATLAB software proposed in this study, engine exciting fores can be predicted. Also using ADAMS/Engine module and ADAMS/View software, engine exciting forces can be predicted.

• Journal of Power System Engineering
• /
• v.12 no.2
• /
• pp.23-28
• /
• 2008

The primary objective of this study is to truly understand reaction force be due to engine exciting force. Exciting forces of the engine apply a source of the vehicle NVH(Noise, Vibration, Harshness). To understand reaction force was applied MSC.Nastran software. Analyzed frequency response analysis of powertrain mount system. First, engine exciting force was applied field function. Also nonlinear characteristics was applied field function : such as dynamic spring constant and loss factor. And nonlinear characteristics was applied CBUSH. Generally characteristics of rubber mount is constant frequency. But characteristics of hydraulic mount depend to frequency. Therefore nonlinear characteristics was applied. Powertrain mounting system be influenced by powertrain specification, mount position, mount angle and mount characteristics etc. In this study, we was analyzed effects of powertrain mounting system. And we was varied dynamics spring constant and loss factor of mounts.