Vibration Of Internal Combustion Engine Research Articles

Productivity analysis focusing on internal combustion engine vibration when using local fuels and additives

The purpose of this article is to analyze the vibrations and behavior of an internal combustion engine of three vehicles: A1, J1, K1 which are exposed to both the geography, relief and road conditions of the Metropolitan District of Quito. To implement the quantitative methodology in the research it is important to perform a complete analysis of the vehicle based on its technical data sheet: A1, J1, K1, in order to identify both fuel consumption and the use of additives to reduce the friction that cause vibrations in the engine, especially the condition of the road. In addition, it is important to check how the level of vibrations can be reduced, the percentage of fuel when using additives and to verify the data provided by the vibration study of each vehicle. The results show that the tests carried out at 3500 RPM in vehicle A1 show a value of 27%, in vehicle J1 a value of 17% and vehicle K1 a value of 15%, these values are related to the use of additives. The results of the research are linked to field tests, individual tests, comparison of results and discussion of the feasibility of each of the tests performed on each vehicle to find similarities or marked differences.

Method for synthesis of an intelligent automatic system for diagnosing combustion engine vibration of the power supply system of an unmanned vessel

The paper considers the implementation prospects and features of the synthesis of an intelligent automatic system for diagnosing the internal combustion engine vibration of a power supply system in terms of developing technologies for automatic or remote control of unmanned vessels. The paper addresses the issue of predicting the technical condition of a combustion engine using available diagnostic methods. The study focuses on the equipment required for monitoring and analyzing the technical condition of the engine of an unmanned vessel when operating in automatic or remotely controlled mode. An algorithm has been developed for collecting, storing and accumulating data on the condition of the engine components and units in the on-board information system of the vessel to exchange data on the condition of the engine and its components during remote monitoring and to determine fault codes. The approaches to the synthesis of an intelligent automatic system for diagnosing the combustion engine vibration are considered from a methodological point of view. Vibration diagnostics equipment used for the analysis of the technical condition of the engine is proposed. Some results of the classification of the technical condition of the engine are presented. The expediency of introducing and using hybrid intelligent systems based on artificial neural networks is exemplified by diagnostics of the MITSUBISHI S16R engine.

English Estimating Fatigue of Nr45 Natural Rubber Used in Crank Pulley

Rubber is used as a vibration damper in many engineering applications, especially in the automotive industry. Rubber is used to dampen torsional vibration in internal combustion engines. Therefore, crank pulleys are used to dampen the crankshaft in a certain frequency range. Rubber durability is very important for the crank pulley to perform its duty for a long time. In this study, the dynamic life of NR45 natural rubber with two different mixtures used in crank pulleys was determined by the prepared test approach. A metal-rubber component structure used in the slip test samples was formed and produced. The metal-rubber component is left to force the rubber in the vertical direction with its natural frequency and specified amplitude to simulate torsional vibration in crank pulleys. A test setup design was carried out to force the metal-rubber component at the determined frequency. In the study, life expectancy estimates based on amplitude and frequency were created on experimental data.

Analysis of water coolant pressure fluctuation induced by piston slap

Liner cavitation is caused by water pressure fluctuation in water coolant passage. When the negative pressure falls below the saturated vapor pressure, the impulsive pressure following the implosion of cavitation bubbles causes cavitation erosion on wet cylinder liner surface. Prediction of coolant pressure fluctuation is crucial to relieve liner cavitation erosion. Vibration of internal combustion engine especially liner vibration is thought of as the primary cause of liner cavitation. Piston slap is deemed as the major factor of engine vibration. The present work establishes a coupled system between entire engine structure and water coolant passage acoustic field considering their vibration characteristics by finite element method and boundary element method. Mechanism of piston slap is proposed and the resulting slap forces are applied on cylinder to predict water coolant pressure fluctuation. The influence of sound speed variation of acoustic field on pressure fluctuation is discussed. The contributions of natural modes of engine and water acoustic field to largest negative pressure are analyzed.

Effect of Sensors Location on Measuring the Vibration of Internal Combustion Engine

Effect of Sensors Location on Measuring the Vibration of Internal Combustion Engine

Combustion parameter estimation for ICE from surface vibration using frequency spectrum analysis

Surface vibration of internal combustion engine containing abundant combustion information could be analyzed using different signal processing methods, in which frequency-domain analysis is one of the common methods. In order to eliminate influence of adjacent excitation and enhance frequency resolution, S-Transform method was used to obtain frequency information of combustion pressure and surface vibration signal measured from a single-cylinder and 12-cylinder diesel engine. Based on the results of the single-cylinder diesel engine, the relationship between frequency information of vibration acceleration and characteristics parameters of combustion like peak combustion pressure and peak pressure rise rate was analyzed. It could be concluded that there existed a good linear relationship between the summation of frequency amplitude in the selected frequency range and the characteristics parameters under the same engine speed working condition. Frequency-domain analysis conducted with the 12-cylinder engine showed that characteristics parameters of combustion could be estimated from the summation of frequency amplitude when engine worked for power generation application, which was maintained the same engine speed normally.

Research on Experimental Method for Obtaining Independent Combustion Noise of Internal Combustion Engine

Internal combustion engine noise sources are complex and changeable. Combustion noise is usually drowned out by mechanical noise and aerodynamic noise. Traditional noise source identification methods can only qualitatively identify combustion noise. In order to quantitatively obtain the independent pure combustion noise of an internal combustion engine, it is necessary to design and build a separate noise source simulation test bench. In this paper, the combustion noise separation test bench based on transfer function method is designed and implemented. In the test, a pressure pulse device is installed in the combustion chamber. When the piston is at top dead center (TDC), pulse pressure is generated to excite the internal combustion engine to radiate noise. The pressure signal and noise signal are utilized to obtain the transfer function of combustion pressure and noise. Then, according to the cylinder pressure and transfer function, the combustion noise can be directly calculated. The test was carried out on 4120SG diesel engine. Experimental results show that when the internal combustion engine is under 1500 rpm and no‐load condition and 800 rpm and no‐load condition, the frequency components of independent pure combustion noise are both mainly concentrated at 1100 Hz, 1400 Hz, and 3000 Hz. Furthermore, the internal combustion engine vibration test method and the combustion noise empirical formula calculation method are both carried out to show accuracy and effectiveness of the obtained independent combustion noise through the combustion noise separation test based on transfer function method.

Radiation Noise Separation of Internal Combustion Engine Based on Gammatone-RobustICA Method

In the internal combustion engine noise source separation process, the combustion noise and the piston slap noise are found to be seriously aliased in time-frequency domain. It is difficult to accurately separate them. Therefore, the noise source separation method which is based on Gammatone filter bank and robust independent component analysis (RobustICA) is proposed. The 6-cylinder internal combustion engine vibration and noise test are carried out in a semianechoic chamber. The lead covering method is adopted to isolate the interference noise from numbers 1 to 5 cylinder parts, with only the number 6 cylinder parts left bare. Firstly, many mode components of the measured near-field radiated noise signals are extracted through the designed Gammatone filter bank. Then, the RobustICA algorithm is utilised to extract the independent components. Finally, the spectrum analysis, the continuous wavelet time-frequency analysis, the correlation function method, and the drag test are employed to further identify the separation results. The research results show that the frequency of the combustion noise and the piston slap noise are, respectively, concentrated at 4025 Hz and 1725 Hz. Compared with the EWT-RobustICA method, the separation results obtained by the Gammatone-RobustICA method have very fewer interference components.

Piezoelectric energy harvesting from torsional vibration in internal combustion engines

This paper presents a piezoelectric energy harvester (PEH), which harvests electric power energy from torsional vibration induced by internal combustion (IC) engines. The PEH can generate electric power for a wireless sensor node system by simply attaching a compact cantilever beam structure to the surface of the rotating shaft. A prototype PEH is manufactured by using a commercial piezoelectric wafer and mounted on a torque converter (i.e., engine output). The primary harvesting performance of the PEH prototype is experimentally validated through laboratory tests using a low-inertia dynamometer. The frequency response function of the PEH is investigated to evaluate its harvesting capability. Finally, its potential application to a wireless shaft torque transducer is discussed.

Analysis of main journal vibration of internal combustion engine by systematic method considering oil film forces

Influences of system parameters of the piston-crankshaft system in an internal combustion engine on the main journal vibration are investigated with the proposed systematic method considering oil film forces. In doing so, oil film forces of the lubricated piston pack and main journal were solved and then incorporated into the dynamic equations for the components in the system, through which the system parameter influences on the main journal vibration are simulated, and further verified. The numerical results show that there exists an optimal rotational speed of the internal combustion engine to keep the main journal stable. Moreover, the varied ratio of the connecting-rod length to piston diameter, unbalance mass of crankshaft, and damping coefficient of the main journal can change the main journal’s stability, and its vibration amplitude.

The Time-Frequency Analysis Method Based on EMD White Noise Energy Density Distribution Characteristics of the Internal Combustion Engine Vibration

For the limitations of HHT of the internal combustion engine vibration signal analysis, and the problem of WVD cross-term suppression methods existing aggregation and cross-term component suppression conflicting, the time-frequency analysis method based on EMD white noise energy density distribution characteristics of the internal combustion engine vibration is proposed. First, the internal combustion engine vibration signal was decomposed into the independent series intrinsic mode function (IMF) with different characteristic time scales by using EMD decomposition method. Then, based on the energy density distribution characteristics of the white noise in EMD decomposition, used the distribution interval estimation curve of the IMFs energy density logarithm of white noise with the same length of the original signal as cordon for false pattern component, identified and eliminated false mode component of vibration signal IMFs component, analysised of each IMF with Wigner-Ville. Finally, the Wigner-Ville analysis results of each IMF were linear superposed in order to reconstruct the original signal time-frequency distribution. Simulation and engine vibration time-frequency analysis results show that this method has an excellent time-frequency characteristics, and can successfully extract feature information of the internal combustion engine cylinder head vibration signal.

Multiple Sinusoidal Vibration Test Development for Engine Mounted Components

Durability testing is required before vehicle launching to prevent failure before designed life. Limited publications were found on specifying vibration testing to validate durability and reliability of engine mounted components. These published test methods did not consider engine firing order effects and oversimplified the vibration profiles. In this paper, a new ordered multiple sinusoidal vibration test method is proposed to improve the existing procedures. The test method is designed to fulfill an infinite life durability requirement for engine mounted components subjected to a four-stroke internal combustion engine vibration. An innovative test development procedure, based on engine vibration field data, is illustrated in details in this paper. The ordered multiple sinusoidal vibration test method covers the choice of sweep type, sweep time, frequency range, vibration magnitude and profile, and test duration. Instead of obtaining the vibration magnitude directly from order analysis results, vibration magnitudes are determined by fully analyzing the vibration data in both time domain and frequency domain. Test profiles designed by enveloping method are proposed for a better represent of the engine excitations.

Minimization of IC engine rubber mount displacement using genetic algorithm

Though many computationally expensive internal combustion engine vibration models are available, simple and computationally efficient tools are required for preliminary design work. The unbalanced forces of rotating and reciprocating parts are the primary sources for the engine vibrations which in turn reduce the durability and reliability of consumer and commercial automotives. So, a significant vibration isolation is needed for both engine and interface between the engine mounts, and it could be obtained with the help of rotating balancing disks attached at both ends of the crank shaft. The masses of the balancing disks and their lead angles influence the effectiveness of vibration isolation that can be measured by the engine mount displacement caused due to engine vibrations. The optimized masses of balancing disks and their lead angles minimize the engine mount displacements that ensure the effective vibration isolation. In this paper, the genetic algorithm is employed to optimize the masses of the balancing disks and their lead angles with an objective of minimizing the engine mount displacements.

Comparison of different techniques for time-frequency analysis of internal combustion engine vibration signals

In this study, we report an analysis of cylinder head vibration signals at a steady engine speed using short-time Fourier transform (STFT). Three popular time-frequency analysis techniques, i.e., STFT, analytic wavelet transform (AWT) and S transform (ST), have been examined. AWT and ST are often applied in engine signal analyses. In particular, an AWT expression in terms of the quality factor Q and an analytical relationship between ST and AWT have been derived. The time-frequency resolution of a Gaussian function windowed STFT was studied via numerical simulation. Based on the simulation, the empirical limits for the lowest distinguishable frequency as well as the time and frequency resolutions were determined. These can provide insights for window width selection, spectrogram interpretation and artifact identification. Gaussian function windowed STFTs were applied to some cylinder head vibration signals. The spectrograms of the same signals from ST and AWT were also determined for comparison. The results indicate that the uniform resolution feature of STFT is not necessarily a disadvantage for time-frequency analysis of vibration signals when the engine is in stationary state because it can more accurately localize the frequency components excited by transient excitations without much loss of time resolution.

Analysis of Piston Slap Induced Noise and Vibration of Internal Combustion Engine (Effect of Piston Profile and Pin Offset)

This paper presents the analytical method to evaluate the impact force and engine noise induced by piston slap considering the detailed piston profile and dynamic characteristics of the piston. This method was applied to examine the effect of the piston profile and piston pin offset on the piston slap impact force and its induced engine noise. Present numerical method showed that increasing the upper clearance of the piston skirt enlarged the higher frequency components of the piston impact force and engine noise and this was verified by the experimental results. The analysis revealed that piston movement at the vicinity of the combustion top dead center was governed by the friction moment around the piston pin and the additional piston pin offset moment induced by combustion pressure could cancel this friction moment and reduce the piston impact force if the piston pin was offset to the major thrust side. This analytical results was confirmed by the measured results of actual diesel engine.

ピストンスラップによるエンジン振動・騒音の研究 : ピストン形状やピンオフセットの影響

ピストンスラップによるエンジン振動・騒音の研究 : ピストン形状やピンオフセットの影響

Analysis of torsional vibration in internal combustion engines: Modelling and experimental validation

This paper reports on a study of the crankshaft torsional vibration phenomenon in internal combustion engines. The steady state of the state equation is solved by the transition state matrix and the convolution integral. This formulation is applied to the model of a six-cylinder diesel engine manufactured by MWM International Motores®. The analyses consider a rubber and viscous damper assembled to the crankshaft front-end. An analysis of the torsional vibrations indicates the dynamic loading on each crankshaft section, and these loads can be applied as boundary conditions in a finite element model to predict the safety factor of the component and to compare the system's behaviour with rubber and viscous damper options. This study highlights the importance of torsional vibration analyses in the structural dimensioning of crankshafts. The results of the torsional vibration amplitude are compared with measured values to experimentally validate the proposed mathematical model.

Blind separation of internal combustion engine vibration signals by a deflation method

Internal combustion engines have several vibration sources, such as combustion, fuel injection, piston slap and valve operation. It is necessary to separate the different vibration sources and then analyze each of them individually. This paper attempts to separate the vibration sources by blind source separation techniques and proposes a combination of the Blind Least Mean Square algorithm with a deflation method to separate several sources. The combined methods are first verified on simulated sources and then applied to engine signals. Separation results show that cylinder pressure consists of two sources—one is a smooth low frequency part due to compression and expansion caused by piston movement; the other is the high frequency part due to combustion.

Fully Coupled Rigid Internal Combustion Engine Dynamics and Vibration—Part II: Model-Experiment Comparisons

In internal combustion engine vibration modeling, it is typically assumed that the vibratory state of the engine does not influence the loads transmitted to the engine block from its moving internal components. This one-way-coupling assumption leads to energy conservation problems and does not account for Coriolis and gyroscopic interactions between the engine block and its rotating and reciprocating internal components. A new seven-degree-of-freedom engine vibration model has been developed that does not utilize this assumption and properly conserves energy. This paper presents time and frequency-domain comparisons of this model to experimental measurements made on an inline six-cylinder heavy-duty Diesel engine running at full load at peak-torque (1200 rpm) and rated (2100 rpm) speeds. The model successfully predicts the overall features of the engine’s vibratory output with model-experiment correlation coefficients as high as 70 percent for vibration frequencies up through third engine order. The results are robust to variations in the model parameters. Predictions are less successful at the detail level and at higher frequencies because of uncertainties in the actual imperfections of the test engine, and because of the influence of unmodeled engine components.

Limitations of Rigid Body Descriptions for Heavy-Duty Diesel Engine Vibration

Internal combustion engine vibration modeling commonly relies on assuming the engine is a linearly reacting rigid body, thereby ignoring rotating, reciprocating, and nonsolid engine components. Limitations of this approach are identified from a series of experiments on a heavy-duty in-line six-cylinder Diesel engine typical of Class VIII trucks. Measurement of all three orthogonal vibration force components were made at each of three engine mounts during standard impact-excitation modal identification tests on the quiescent engine and during engine operation. The running-engine vibration forces, measured throughout the test engine load and speed operating envelope, were projected onto the quiescent-engine rigid body modes to determine the modal content and residual vibration as a function of frequency. Modal decomposition results for the running engine show that the quiescent-engine rigid body modes, with modal frequencies between 5.6 and 26.3 Hz, account for 80 percent or more of the measured engine vibration forces for all engine speeds and loads in a bandwidth from zero to 200 Hz. The likely origins of the residual vibration within this bandwidth are discussed.