• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2009.10a
• /
• pp.248-253
• /
• 2009

The propulsion system which apply the diesel engine with reduction gear as prime mover, generally installs the elastic coupling between engine and intermediate shaft, This coupling can isolate the vibratory torque excited by diesel engine, or the excess transient torque and moment occurring by external impact. So, diesel engine and reduction gear can safely operate by elastic coupling. Unfortunately, the elastic coupling for skimmer vessel was repeatedly broken by unknown vibration during the sea trial In this paper, the authors are searching for the possibilities and causes of the elastic coupling failure, via the global vibration measurement and the past incident investigation.

• Journal of KSNVE
• /
• v.7 no.4
• /
• pp.681-688
• /
• 1997

The purpose of engine mount system is to reduce the noise and vibration caused by engine vibration, and to decouple the roll and bounce mode at idle. To reduce the noise and vibration level in a vehicle, it is important to make the design optimization of engine mount system that consider the moment of inertia and inclination of mount rubber. As a result, according to the definition of Torque Roll Axis (TRA), the vibration axis at idle must be on the TRA or very close to it. In this paper, we studied the effect of the design optimization of engine mount system. And we have achieved good improvements in noise and vibration quality of F.R. vehicle.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.3
• /
• pp.1298-1303
• /
• 2015

Diesel engine generators are widely used in the world, especially in remote site power systems as distributed generators. A weak distribution feeder with a small diesel engine may suffer from voltage and power fluctuations due to misfiring of the engine cylinder. In this study, new generator model with example engine torque was developed for the electromagnetic transient analysis program for power systems named XTAP. The configuration and verification results of the developed model are presented in the paper. The model is considered to be useful for analyses of small power systems with those diesel engines.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.9 no.6
• /
• pp.65-75
• /
• 2001

Modern vehicles require a high degree of refinement including good driveability. Vehicle driveability, which becomes a key decisive factor f3r marketability, is affected by many parameters such as engine control and the dynamic characteristics in drive lines. Therefore engine and drive train characteristics should be considered to achieve a well balanced vehicle response simultaneously. This paper describes experimental procedures which have been developed to measure engine torque and investigate shuffle characteristics. To analyze the vehicle dynamic behavior, fractional torques and inertia mass moment of engine, and drive train were measured. Shuffle characteristics during tip-in condition were investigated in an experimental vehicle at 2nd and 3rd gear stages. It was found that the shuffle characteristics were caused by sudden changes of engine torque and have a different vibration frequency with gear stage variation. Inertia mass moment of engine including flywheel rotation showed a key factor for the shuffle characteristics.

• Proceedings of the KSME Conference
• /
• 2008.11b
• /
• pp.2916-2921
• /
• 2008

This paper presents the performance and characteristics of small spark-ignited small 2-stroke engine. A single cylinder, two-stroke, air cooled 23cc SI engine for brush-cutter was used in this study. For the performance of the engine, rpm, torque, fuel consumption and lubricate oil consumption were measured, and also HC, CO, NOx emissions and excess air ratio according to throat open ratio under two lubrication method were measured and analyzed. The results showed that maximum of engine rpm is nearly same in both methods and also, torque, power is similar. exhaust emissions tend to decrease with throat open ratio.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.5 no.2
• /
• pp.94-110
• /
• 1997

In the present study, a mean torque predictive model has been proposed and experimentally validated. It includes induction air mass model, fuel delivery model and mean production mode. Air induction and fuel delivery model considering dynamic behaviors of air induction and fuel delivery were proposed to predict the air-fuel ratio excursions under transient condition. Torque function model reflects thermal efficiency, volumetric efficiency, friction and effect of spark timing. In the spark timing model, knock limit and acceleration retard are included. Experiments were carried out to validate the simulation model for the step changes of throttle at constant engine speed. The results show reasonable agreements between simulation and experiment at fully warmed condition. Using this model, fueling strategies are varied with fast throttle open and it can predict air-fuel ratio excursion and IMEP.

• International Journal of Automotive Technology
• /
• v.6 no.5
• /
• pp.529-536
• /
• 2005

This paper presents a novel design of a fuzzy control strategy (FCS) based on torque distribution for parallel hybrid electric vehicles (HEVs). An empirical load-regulating vehicle operation strategy is developed on the basis of analysis of the components efficiency map data and the overall energy conversion efficiency. The aim of the strategy is to optimize the fuel economy and balance the battery state-of-charge (SOC), while satisfying the vehicle performance and drivability requirements. In order to accomplish this strategy, a fuzzy inference engine with a rule-base extracted from the empirical strategy is designed, which works as the kernel of a fuzzy torque distribution controller to determine the optimal distribution of the driver torque request between the engine and the motor. Simulation results reveal that compared with the conventional strategy which uses precise threshold parameters the proposed FCS improves fuel economy as well as maintains better battery SOC within its operation range.

• Journal of Biosystems Engineering
• /
• v.38 no.3
• /
• pp.171-179
• /
• 2013

Purpose: A simulator for the design and performance evaluation of a tractor with a hydro-mechanical transmission (HMT) was developed. Methods: The HMT consists of a hydro-static unit (HSU), a swash plate control system, and a planetary gear. It was modeled considering the input/output relationship of the torque and speed, and efficiency of HSU. Furthermore, a dynamic model of a tractor was developed considering the traction force, running resistance, and PTO (power take off) output power, and a tractor performance simulator was developed in the co-simulation environment of AMESim and MATLAB/Simulink. Results: The behaviors of the design parameters of the HMT tractor in the working and driving modes were investigated as follows; For the stepwise change of the drawbar load in the working mode, the tractor and engine speeds were maintained at the desired values by the engine torque and HSU stroke control. In the driving mode, the tractor followed the desired speed through the control of the engine torque and HSU stroke. In this case, the engine operated near the OOL (optimal operating line) for the minimum fuel consumption within the shift range of HMT. Conclusions: A simulator for the HMT tractor was developed. The simulations were conducted under two operation conditions. It was found that the tractor speed and the engine speed are maintained at the desired values through the control of the engine torque and the HSU stroke.

• Journal of Advanced Marine Engineering and Technology
• /
• v.39 no.7
• /
• pp.722-728
• /
• 2015

The demand for shipboard energy management is expected to gradually increase based on ship energy efficiency management plans (SEEMPs), which have been in use since January 1, 2013. Therefore, the fuel consumption of the main engine, which occupies the greatest portion of the energy used, along with elements related to the engine power, should be strictly monitored. There are many different methods for indicating the engine power. However, this study performed an experiment to monitor the status of a ship's engine power in real time using an encoder and a proximate switch, which are economical to purchase and easy to install. In the experiment, the angular velocity during one cycle of a two-stroke low-speed engine was measured, and the measured data were converted to the torque fluctuation. The angular velocity during an abnormal firing condition in the cylinder was also measured, and the torque fluctuation as a result of a misfire was considered. The results were compared with sea trial data to determine the reliability. In this study, the status of the engine power was determined using the torque fluctuation of the main engine in an operating ship.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.3 no.2
• /
• pp.102-111
• /
• 1995

The non-periodic fluctuation 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 along with the requirements of higher performance. The torsional vibration of the automotive driveline can be reduced by smoothing the fluctuation by adjusting the torsional characteristics of the clutch-disc. Computer simulation of the driveline 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 of the model were evaluated with experimental data. By executing a simulation using the model, it has become possible to obtain the clutch-disc torsional characteristics for reducting the torsional vibration at creeping.