• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.93-98
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• 2010

One of the most effective key factors to improve performance of automotive reciprocating compressor is the design of suction and discharge reed valves. Reed valves are also the major sources of compressor noise. Valve motion is highly coupled with refrigerant flow. In this study, a process of fluid-structure interaction analysis was developed to predict the cylinder inner flow and the dynamic behavior of valve simultaneously. Interface programs computational structural dynamics code. The full cycle simulations of compressor were performed using FSI analysis was alidated by comparing the simulation results with the experimental results.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1442-1445
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• 2003

In precision machinery industry, it's required with small size and low noise design to using in constant liquid delivery equipment. To accomplish it's purpose, we designed the check valve with rubber sheet of circle shapes as a possible assembly in pump body. The test equipment for piezoelectric pump was able to test pressure-flow property and output property of piezoelectric pump by variation(magnitude of voltage and frequency) of input power.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.2
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• pp.69-74
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• 2004

In general the surge pressure generated in hydraulic systems causes noise, vibration and odd effect to the system. To reduce the surge pressure, high frequency PWM control of 20KHz was attempted. To estimate the braking noise caused by surge, a vehicle equipped with on-board ABS hydraulic modulator has been experimented with respect to the various breaking condition. Thorough this experiments, it was found that breaking noise has been reduced using high frequency PWM control method compare with low frequency method. To evaluate high frequency control m practice, including verification of general functionality, EMI tests was experimented. Its was found that it is necessary to have the solution to electromagnetic interference(EMI) generated by switching elements.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.861-863
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• 2003

The method of measurement for laboratory tests on noise emission from appliances and equipment used in water supply installations is specified in ISO 3822-1. This part of standard gives detailed descriptions for mounting and operating draw-off taps and mixing valves in such laboratory test. Draw-off taps and mixing valves are the most common kind of appliance used in water supply installations.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.986-989
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• 2004

The method of measurement for laboratory tests on noise emission from appliances and equipment used in water supply installations is specified in ISO 3822-1 This part of standard gives detailed descriptions for mounting and operating in-line valves and appliances, which control the flow, pressure or temperature of the water in water supply installations in such laboratory tests.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.1070-1072
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• 2003

In this paper, Firstly, it is shown that the high vibration source of piping system is the pulsation transmission of pipe line element ,such as, orifice plate, valves and the control valve is a broad band source and the branch wall and the cavity have vortex frequency Secondly, in order to decrese the turbulence vibration of piping system, the practical analysis of piping flow by EFD have been developed and its effectiveness is investigated as applying it at piping system practically.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.868-869
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• 2013

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.3869-3875
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• 2012

In this study, mathematical modeling and experimental analysis were executed in order to evaluate the valve dynamic characteristics when the hydraulic pressure applied. High pressure on the master cylinder effects on the valve dynamic characteristics have been analyzed. The pulsation pressure generated in hydraulic systems causes noise, vibration and odd effect to the system. To reduce the pulsation pressure, high frequency PWM control of 20KHz was attempted. Also, an analytic method is proposed for the resultant forces of electromagnetism and hydraulic pressure generated in the real vehicle electro stability program. Consequently, results of solenoid valve dynamic characteristics analysis derived in the study can be confirmed criteria for the optimal control of electronic stability program system.

• Journal of Drive and Control
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• v.12 no.4
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• pp.54-59
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• 2015

Due to the tendency to use high speed pneumatic cylinders to improve productivity, cushioning devices are adopted to decelerate the piston motion of pneumatic cylinders to reduce noise, vibration, and impact. This paper presents a comparison of the cushion characteristics of a high speed pneumatic cylinder with a relief valve type cushioning device. The system parameters selected are the damping coefficient, Coulomb friction, heat transfer coefficient, and cracking pressure of the relief valve in the air cushioning device. The integral of the time multiplied square error (ITSE) is used to quantitative measure the cushioning performance to assess the effect of varying these. The cushioning performance achieved good results when the ITSE is a minimum value. In a comparison of the piston displacement and velocity with the variations in system parameters, the heat transfer coefficients are not as significantly affected as the other. Also, the cracking pressure of the relief valve is mainly affected by the pressure and temperature in the cushion chamber.

• Nuclear Engineering and Technology
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• v.53 no.1
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• pp.148-163
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• 2021

Timely fault identification is important for safe and reliable operation of the electric valve system. Many research works have utilized different data-driven approach for fault diagnosis in complex systems. However, they do not consider specific characteristics of critical control components such as electric valves. This work presents an integrated shallow-deep fault diagnostic model, developed based on signals extracted from DN50 electric valve. First, the local optimal issue of particle swarm optimization algorithm is solved by optimizing the weight search capability, the particle speed, and position update strategy. Then, to develop a shallow diagnostic model, the modified particle swarm algorithm is combined with support vector machine to form a hybrid improved particle swarm-support vector machine (IPs-SVM). To decouple the influence of the background noise, the wavelet packet transform method is used to reconstruct the vibration signal. Thereafter, the IPs-SVM is used to classify phase imbalance and damaged valve faults, and the performance was evaluated against other models developed using the conventional SVM and particle swarm optimized SVM. Secondly, three different deep belief network (DBN) models are developed, using different acoustic signal structures: raw signal, wavelet transformed signal and time-series (sequential) signal. The models are developed to estimate internal leakage sizes in the electric valve. The predictive performance of the DBN and the evaluation results of the proposed IPs-SVM are also presented in this paper.