• Title, Summary, Keyword: Engine Noise

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A New Type of Active Engine Mount System Featuring MR Fluid and Piezostack (MR 유체와 압전스택을 특징으로 하는 새로운 형태의 능동 엔진마운트 시스템)

  • Lee, Dong-Young;Sohn, Jung-Woo;Choi, Seung-Bok
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.6
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    • pp.583-590
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    • 2009
  • An engine is one of the most dominant noise and vibration sources in vehicle systems. Therefore, in order to resolve noise and vibration problems due to engine, various types of engine mounts have been proposed. This work presents a new type of active engine mount system featuring a magneto-rheological (MR) fluid and a piezostack actuator. As a first step, six degrees-of freedom dynamic model of an in-line four-cylinder engine which has three points mounting system is derived by considering the dynamic behaviors of MR mount and piezostack mount. In the configuration of engine mount system, two MR mounts are installed for vibration control of roll mode motion whose energy is very high in low frequency range, while one piezostack mount is installed for vibration control of bounce and pitch mode motion whose energy is relatively high in high frequency range. As a second step, linear quadratic regulator (LQR) controller is synthesized to actively control the imposed vibration. In order to demonstrate the effectiveness of the proposed active engine mount, vibration control performances are evaluated under various engine operating speeds(wide frequency range) and presented in time domain.

A New Type of Active Engine Mount System Featuring MR Fluid and Piezostack (MR 유체와 압전스택을 특징으로하는 새로운 형태의 능동 엔진마운트 시스템)

  • Lee, Dong-Young;Sohn, Jung-Woo;Choi, Seung-Bok
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.444-449
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    • 2009
  • An engine is one of the most dominant noise and vibration sources in vehicle systems. Therefore, in order to resolve noise and vibration problems due to engine, various types of engine mounts have been proposed. This work presents a new type of active engine mount system featuring a magneto-rheological (MR) fluid and a piezostack actuator. As a first step, six degrees-of freedom dynamic model of an in-line four-cylinder engine which has three points mounting system is derived by considering the dynamic behaviors of MR mount and piezostack mount. In the configuration of engine mount system, two MR mounts are installed for vibration control of roll mode motion whose energy is very high in low frequency range, while one piezostack mount is installed for vibration control of bounce and pitch mode motion whose energy is relatively high in high frequency range. As a second step, linear quadratic regulator (LQR) controller is synthesized to actively control the imposed vibration. In order to demonstrate the effectiveness of the proposed active engine mount, vibration control performances are evaluated under various engine operating speeds (wide frequency range) and presented in time domain.

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Effects of Design Parameters on Rattle Noise in a Direct Engine-PTO Driveline of Tractors (엔진 직결식 PTO 전동 라인의 주요 설계 변수가 PTO 변속부의 치타음에 미치는 영향)

  • Park Y.J.;Kim K.U.
    • Journal of Biosystems Engineering
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    • v.31 no.4
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    • pp.323-333
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    • 2006
  • Introduction of a direct engine-PTO driveline to agricultural tractors has reduced production cost and increased transmission efficiency of the PTO driveline. However, this type of PTO driveline has caused a severe rattle noise in the PTO gearbox under idle conditions. This study was conducted to investigate the causes of the rattle noise and the effects of driveline parameters on it. A mathematical model was developed for a direct engine-PTO driveline. The model was proved experimentally to be accurate enough to simulate the dynamic characteristics of the PTO driveline motions. The simulation study showed that the rattle noise was caused by collisions between the driving and driven gears in the PTO gearbox due to velocity variation of the gears, which was induced by torque fluctuations from the engine. It was also found that the rattle noise decreased with the drag torque and mass moment of inertia of the engine flywheel. Smaller mass moment of inertia of the driven gears and backlash also reduced the rattle noise. However, increasing the drag torque and mass moment of the engine flywheel or decreasing the backlash and mass moment of inertia of the driven gears were limited practically by their detrimental effects on transmission efficiency, gear strength and smooth meshing of the gears.

A Study on the Noise Reduction of Compartment of Vehicle Using Sensitivity Analysis of Engine Exciting Force (엔진 가진력의 감도해석을 이용한 차실 소음 저감에 관한 연구)

  • 오재응;김태욱;송재은;이해승
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.4
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    • pp.171-178
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    • 1997
  • Vehicle interior noise has become increasingly important in this recent years. The noise of a vehicle is one of the important problems in a vehicle design. The interior noise is caused by various vibration sources of vehicle compartment. The booming noise of a vehicle can be significantly affected by vibrations transmitted from engine excitation forces to the vehicle body. Specially, we are interested in the state of transmission paths such as engine mounts to reduce noise in a vehicle compartment. In this paper, we have been calculated the contribution of each transmission path such as engine mounts to interior noise. To identify contribution of each input sources and transmission paths to output, the effectiveness of each input component to output is calculated. Sensitivity analysis is carried out for investigation of contribution to output due to input variations. With the simulation of magnitude and phase change of inputs using vector synthesis diagram, the trends of synthesized output vector are obtained. As a result, we suggested sensitivity analysis of vector synthesis as a technique of prediction and control for noise in a vehicle compartment.

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Study on Noise Generation Characteristics of Simulated EGR System for Compression Ignition Diesel Engine (압축착화 디젤엔진의 모사 EGR 시스템에 의한 소음 특성 변화 분석)

  • Park, B.;Yoon, S.;Park, S.;Park, J.
    • Journal of ILASS-Korea
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    • v.19 no.4
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    • pp.204-210
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    • 2014
  • Experimental study was conducted to investigate the effect of EGR(exhaust gas recirculation) on engine noise using single cylinder combustion ignition engine. Under constant engine rotary speed of 1200 RPM, 8 mg fuel quantity was injected with 15, 18 and 21% of oxygen ratio and 1400 bar of injection pressure. Using the in-cylinder pressure data acquired by a piezoelectric transducer, the engine performance parameters were calculated. Radiated engine noise measured for 10 seconds was analyzed using spectral characteristics and sound quality metrics such as loudness, sharpness, roughness. From the obtained engine performance parameters and sound quality metrics, effect of oxygen ratio of the premixed air, start of injection timing on frequency characteristic and sound quality metrics were analyzed. Correlation analysis was conducted between MPRR(maximum pressure rise rate), RI(ringing intensity) and sound quality metrics. RI was identified as the most important factor having influence on the sound quality metrics.

Design of Low Noise Engine Cooling Fan for Automobile using DACE Model (전산실험모형을 이용한 자동차 엔진 냉각홴의 저소음 설계)

  • Sim, Hyoun-Jin;Park, Sang-Gul;Joe, Yong-Goo;Oh, Jae-Eung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.5
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    • pp.509-515
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    • 2009
  • This paper proposes an optimal design scheme to reduce the noise of the engine cooling fan by adapting Kriging with two meta-heuristic techniques. An engineering model has been developed for the prediction of the noise spectrum of the engine cooling fan. The noise of the fan is expressed as the discrete frequency noise peaks at the BPF and its harmonics and line spectrum at the broad band by noise generation mechanisms. The object of this paper is to find the optimal design for noise reduction of the engine cooling fan. We firstly show a comparison of the measured and calculated noise spectra of the fan for the validation of the noise prediction program. Orthogonal array is applied as design of experiments because it is suitable for Kriging. With these simulated data, we can estimate a correlation parameter of Kriging by solving the nonlinear problem with genetic algorithm and find an optimal level for the noise reduction of the cooling fan by optimizing Kriging estimates with simulated annealing. We notice that this optimal design scheme gives noticeable results. Therefore, an optimal design for the cooling fan is proposed by reducing the noise of its system.

Design of Low Noise Engine Cooling Fan for Automobile using DACE Model (전산실험모형을 이용한 자동차 엔진 냉각팬의 저소음 설계)

  • Sim, Hyoun-Jin;Lee, Hae-Jin;Lee, You-Yub;Oh, Jae-Eung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.1307-1312
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    • 2007
  • This paper proposes an optimal design scheme to reduce the noise of the engine cooling fan by adapting Kriging with two meta-heuristic techniques. An engineering model has been developed for the prediction of the noise spectrum of the engine cooling fan. The noise of the fan is expressed as the discrete frequency noise peaks at the BPF and its harmonics and line spectrum at the broad band by noise generation mechanisms. The object of this paper is to find the Optimal Design for Noise Reduction of the Engine Cooling Fan. We firstly show a comparison of the measured and calculated noise spectra of the fan for the validation of the noise prediction program. Orthogonal array is applied as design of experiments because it is suitable for Kriging. With these simulated data, we can estimate a correlation parameter of Kriging by solving the nonlinear problem with genetic algorithm and find an optimal level for the noise reduction of the cooling fan by optimizing Kriging estimates with simulated annealing. We notice that this optimal design scheme gives noticeable results. Therefore, an optimal design for the cooling fan is proposed by reducing the noise of its system.

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The Development of an Automatic Noise Inspection System of a Rotating Engine Part Using OLE (OLE 기반 엔진 구동 부품의 자동 소음 검사 장비 개발)

  • 이상철;한성복;최성배
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.10
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    • pp.968-974
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    • 2004
  • Automakers have been forcing their suppliers to guarantee qualities of parts. Then, the suppliers have met the fundamental quality requirements such as dimensions and functions, but they could not sufficiently satisfy the automakers' noise requirements yet because automatic noise inspection systems were little successfully adopted In mass-production lines. This study tried to develop a system for automatically checking noise radiated from a rotating engine part and filtering parts emitting noise higher than criteria: the upper limits of a overall noise level or a noise spectrum. A commercial noise measurement system was used for measuring noise, and then the noise data was transmitted to a governing program through OLE(object, linking and embedding) functions. The governing program, belonging to a total noise inspection system managed the noise measurement and analysis. This system was successfully adapted for distinguishing bad parts according to the noise criteria.

Exhaust Noise Control of Marine Diesel Engine by using Resonator Type Silencer (공명형 소음기를 이용한 박용 디젤엔진 배기 소음 제어)

  • Lee, Tae-Kyung;Joo, Won-Ho;Bae, Jong-Gug
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.350-354
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    • 2008
  • Low frequency exhaust noise of marine diesel engine is one of the most important noise sources in vessels. However, conventional absorptive silencers are limited because the absorptive material is not effective in low frequency range. In the paper, exhaust noise control of marine diesel engine has been studied by using the resonator type silencer, which was composed of concentric hole-cavity resonators. The acoustic performance of the resonator type silencer was verified by the insertion loss measurement considering flow effect. Consequently, its high performance, about $5{\sim}8dB$ noise reduction, in the low frequency range was confirmed by insertion loss measurements conducted in the ship.

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The Dynamic Characteristic Test of Oil pump Integrated Balance Shaft Module (오일펌프 내장형 밸런스 샤프트 모듈의 동특성 시험)

  • Seong, Eun-Je;Kang, Dae-Gyu;Jeong, Chan-Yong;Han, Chang-Soo;Kim, Myung-Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.403-408
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    • 2007
  • According as diesel automobile are produced, reduce noise and vibration that is occurred by characteristic of diesel engine, and need engine room layout optimization and research for light weight of parts. Balance Shaft Module is module parts for vehicles engine to improve performance and efficiency of engine and reduce noise and vibration. These days, an oil pump integrated balance shaft module and an oil sump integrated balance shaft module is on the rising for optimizing of engine room. In this study, produced prototype of oil pump integrated type balance shaft module, and achieved dynamic characteristic test about experimental modal analysis and noise/vibration of balance shaft module.

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