Wyniki wyszukiwania - BazTech

1

Determination of a torsional vibration viscous damper’s operating temperature using a new thermohydrodynamic model

Homik Wojciech, Mazurkow Aleksander, Chmielowiec Andrzej

Transport Problems

|

2023

|

T. 18, z. 4

161--174

EN

This article presents an innovative algorithm and mathematical model of a torsional vibration viscous damper. The problem of torsional vibrations damping in a multicylinder internal combustion engine is extremely important for the reliable operation of a drive unit. The effective reduction of the vibration amplitude extends the service life and prevents failures that generate logistic and transport problems. One of the key parameters used to assess the quality of vibration damper operation is the temperature. This criterion is so important that it is the main indicator for the possible replacement of dampers installed in trucks, locomotives, and ships. Despite the importance of this parameter, the literature lacks mathematical models that describe the thermodynamics of damper operation. Therefore, the authors of this paper developed and presented an innovative thermohydrodynamic model of a torsional vibrations viscous damper, which was used to determine the operating parameters.

2

Data-driven virtual sensor for powertrains based on transfer learning

Karhinen Aku, Hämäläinen Aleksanteri, Manngård Mikael, Miettinen Jesse, Viitala Raine

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2023

|

Vol. 71, nr 6

art. no. e147061

EN

Variation in powertrain parameters caused by dimensioning, manufacturing and assembly inaccuracies may prevent model-based virtual sensors from representing physical powertrains accurately. Data-driven virtual sensors employing machine learning models offer a solution for including variations in the powertrain parameters. These variations can be efficiently included in the training of the virtual sensor through simulation. The trained model can then be theoretically applied to real systems via transfer learning, allowing a data-driven virtual sensor to be trained without the notoriously labour-intensive step of gathering data from a real powertrain. This research presents a training procedure for a data-driven virtual sensor. The virtual sensor was made for a powertrain consisting of multiple shafts, couplings and gears. The training procedure generalizes the virtual sensor for a single powertrain with variations corresponding to the aforementioned inaccuracies. The training procedure includes parameter randomization and random excitation. That is, the data-driven virtual sensor was trained using data from multiple different powertrain instances, representing roughly the same powertrain. The virtual sensor trained using multiple instances of a simulated powertrain was accurate at estimating rotating speeds and torque of the loaded shaft of multiple simulated test powertrains. The estimates were computed from the rotating speeds and torque at the motor shaft of the powertrain. This research gives excellent grounds for further studies towards simulation-to-reality transfer learning, in which a virtual sensor is trained with simulated data and then applied to a real system.

3

Application of fuzzy type II multi-layer Kalman filter for parameters identification of two-mass drive system

Śleszycki Kacper, Wróbel Karol, Szabat Krzysztof, Katsura Seiichiro

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2023

|

Vol. 71, nr 4

art. no. e146107

EN

The paper describes a novel online identification algorithm for a two-mass drive system. The multi-layer extended Kalman Filter (MKF) is proposed in the paper. The proposed estimator has two layers. In the first one, three single extended Kalman filters (EKF) are placed. In the second layer, based on the incoming signals from the first layer, the final states and parameters of the two-mass system are calculated. In the considered drive system, the stiffness coefficient of the elastic shaft and the time constant of the load machine is estimated. To improve the quality of estimated states, an additional system based on II types of fuzzy sets is proposed. The application of fuzzy MKF allows for a shorter identification time, as well as improves the accuracy of estimated parameters. The identified parameters of the two-mass system are used to calculate the coefficients of the implemented control structure. Theoretical considerations are supported by simulations and experimental tests.

4

Momenty skrętne na wale turbozespołu o mocy 1308 MVA podczas zakłóceń sieciowych

Przybysz Jerzy, Wiśniewski Józef

Wiadomości Elektrotechniczne

|

2020

|

R. 88, nr 1

14--19

PL

Przedstawiono analizę momentów skrętnych na wale turbozespołu 1308 MVA występujących podczas rozmaitych zakłóceń sieciowych, obliczonych za pomocą uniwersalnego modelu matematycznego.

EN

Using a universal mathematical model of a turbine-generator unit, torsional shaft moments under different operating conditions are calculated.

5

Vibration control of a rotating shaft by passive mass-spring-disc dynamic vibration absorber

Nguyen Duy Chinh

Archive of Mechanical Engineering

|

2020

|

LXVII, nr 3

279--297

EN

Shaft is a machine element which is used to transmit rotary motion or torque. During transmission of motion, however, the machine shaft doesn’t always rotate with a constant angular velocity. Because of unstable current or due to sudden acceleration and deceleration, the machine shaft will rotate at a variable angular velocity. It is this rotary motion that generates the moment of inertial force, causing the machine shaft to have torsional deformation. However, due to the elasticity of the material, the shaft produces torsional vibration. Therefore, the main objective of this paper is to determine the optimal parameters of dynamic vibration absorber to eliminate torsional vibration of the rotating shaft that varies with time. The new results in this paper are summarized as follows: Firstly, the author determines the optimal parameters by using the minimum quadratic torque method. Secondly, the maximization of equivalent viscous resistance method is used for determining the optimal parameters. Thirdly, the author gives the optimal parameters of dynamic vibration absorber based on the fixed-point method. In this paper, the optimum parameters are found in an explicit analytical solutions, helping the scientists to easily find the optimal parameters for eliminating torsional vibration of the rotating shaft.

6

Modelling of dynamic aspects of operation in railway vehicle traction drive system including the electromechanical coupling

Konowrocki Robert

Zeszyty Naukowe. Transport / Politechnika Śląska

|

2019

|

z. 105

101--111

EN

In this paper, the influence of electromechanical interaction in an electric motor on the railway vehicle driving system dynamics was investigated. This is the train driven by DC. In particular, there is considered influence of electromagnetic field between a rotor and stator on excitation of resonant torsional vibrations of the drive system. Conclusions drawn from the computational results can be very useful during the design phase of these devices as well as helpful for their users during regular maintenance.

7

Diagnostics of the internal combustion engines operation by measurement of crankshaft instantaneous angular speed

Dereszewski Mirosław, Sikora Grzegorz

Journal of KONBiN

|

2019

|

Vol. 49, iss. 4

281--295

EN

Diagnostics based on measuring of crankshaft instantaneous rotational speed allows precise location of damage to the injection system and detection of external disturbances. Active measurement of instantaneous rotational speed requires use of equipment with high sensitivity, permanent assembly at the ends of the crankshaft and the analysis of a very large amount of data. Presented method can be used for measurement of torsional vibration of crankshaft, indirectly through simultaneous measurement of the width of the pulses generated by the encoder disks. Momentary, relative displacement of both disks determines the angle of temporary crankshaft twisting. This paper presents first results of pulse width measurement, obtained by using described system.

PL

Diagnostyka metodą pomiarów chwilowej prędkości obrotowej wału korbowego umożliwia precyzyjną lokalizację uszkodzeń układu wtryskowego oraz wykrywanie zakłóceń zewnętrznych. Aktywny pomiar chwilowej prędkości obrotowej wymaga zastosowania aparatury o dużej czułości, trwałego montażu na końcach wału korbowego oraz analizy bardzo dużej ilości danych. Przedstawiona metoda może posłużyć do obliczania drgań skrętnych wału korbowego pośrednio poprzez symultaniczny pomiar szerokości pulsów generowanych przez tarcze enkoderów. Chwilowe, względne przemieszczenie obu tarcz określa kąt chwilowego skręcenia wału korbowego. W artykule przedstawiono wyniki pierwszych pomiarów szerokości impulsów, uzyskane na opisanym stanowisku badawczym.

8

Experimental verification of the impact of a technical gas-using pneumatic coupling on torsional oscillation

Grega R., Krajňák J., Moravič M.

Zeszyty Naukowe. Transport / Politechnika Śląska

|

2018

|

z. 99

53--63

EN

The field of reducing torsional vibration of mechanical systems has seen the emergence of new flexible coupling designs. Our attention is focused on flexible pneumatic couplings. The flexible member of this coupling design is a pneumatic bag. The typical basic feature of such couplings is that the pneumatic bag allows for a change in air pressure. In the course of developing pneumatic couplings, we have experimented with the use of technical gases other than air for filling pneumatic bags. The aim has been to verify the impact of pneumatic couplings filled with other technical gases on the magnitude of torsional vibration in the mechanical system. For verification itself, two different gases have been used: helium, whose density is lower than air density, and propane butane, whose density is higher than air density. Experimental verification was performed under laboratory conditions on a mechanical system where torsion vibration was produced by a piston compressor.

9

Effect of torsional vibration on woodchip size distribution

Kaššay P.

Zeszyty Naukowe. Transport / Politechnika Śląska

|

2018

|

z. 99

95--104

EN

Nowadays, there is increasing demand for the use of renewable energy sources such as woodchips. One of the important qualitative parameters of woodchips is the size distribution. The aim of this article is to determine the effect of a woodchipper disc’s torsional vibration on the evenness of woodchip length, as well as propose a mathematical solution to this problem by assuming one harmonic component of disc speed and the uniform feed of chipped material. The presented mathematical solution can be used to determine the unevenness of woodchip length when the parameters of torsional vibration are known.

10

A brief overview about the development of torsional vibration calculation and education of methods for their calculation

Zoul V., Kováč P.

Zeszyty Naukowe. Transport / Politechnika Śląska

|

2018

|

z. 99

205--211

EN

Torsional vibration calculation (TVC) is among the basic calculations that are required to support propulsion projects for various vehicles, ships and construction machines. A number of powerful software packages for these calculations already exists. However, the need to respect the physical properties of propulsion systems that are more complex than before has arisen. At the same time, knowledge about system properties and the capabilities of computing systems are also growing, resulting in an increase in new software systems, which could be used for these calculations. In this paper, these new trends are briefly described, with attention paid not only to practical use, but above all to how and to what extent these themes should be presented to students.

11

Wpływ wzrostu dawki paliwa na zmiany amplitud składowych harmonicznych drgań skrętnych wału zespołu spalinowo-elektrycznego

Drewing S., Dereszewski M.

Zeszyty Naukowe Akademii Morskiej w Gdyni

|

2018

|

nr 108

34--42

PL

Artykuł przedstawia wyniki badań wpływu zmian dawki paliwa na składowe harmoniczne drgań skrętnych wału zespołu spalinowo-elektrycznego, ze szczególnym uwzględnieniem składowej harmonicznej odzwierciedlającej wtrysk paliwa. W badaniach wykorzystano metodę pomiaru drgań skrętnych wału za pomocą zmian chwilowych prędkości kątowych.

EN

The article presents the results of research on the impact of changes in the fuel dose on the harmonic components of torsional vibrations of the shaft of the combustion-electric unit, with particular emphasis on the harmonic component responsible for fuel injection. In the tests, the method of measuring torsional vibrations of the shaft was used by means of changes of instantaneous angular velocities.

12

Semi-active torsional vibration isolation utilizing magnetorheological elastomer

Marzuki W. M. R. W., Muthalif A. G. A., Nordin N. H. D.

Vibrations in Physical Systems

|

2018

|

Vol. 29

art. no. 2018014

EN

In rotating machinery, unattenuated excessive torsional vibration leads to damage and excessive wear. This type of vibration, which is transferred from one structure to another can be estimated using torsional transmissibility factor (TTF). The value of the TTF describes the ratio of output to input and reaches its peak at the natural frequency. Hence, the ability to vary coupling stiffness of two rotating shafts will allow the control of the TTF towards better performance and preventions from fatigue loading. Traditionally, passive rubbers are used as a flexible coupling in between two shafts. However, the constant passive stiffness of the material limits its performance. To address this issue, an adaptive coupling based on magnetorheological elastomer (MRE) is proposed to achieve better TTF at varying frequencies. Mathematical modelling, simulation study and experimental results of MRE for torsional vibration isolation are presented in this work. Natural frequency obtained from the TTF shows an increase of about 3 Hz when current changed from 1 to 6 A.

13

Diagnostic aspects of a crankshaft torsional oscillations monitoring by IAS measurement

Dereszewski M.

Journal of KONES

|

2018

|

Vol. 25, No. 1

67--74

EN

Continuous monitoring of diesel engine performance under its operating is critical for prediction of malfunction development and subsequently functional failure detection. Analysis of Instantaneous Angular Speed (IAS) of the crankshaft is considered as one of non-intrusive and effective method of detection of combustion quality deterioration. The article contains presentation of attempt of monitoring of piston engine’s crankshaft torsional vibrations by measurement of Instantaneous Angular Speed at free, and power output ends of the engine’s crankshaft. The angular speed measurements was done using two optical sensors for reading the IAS, mounted at shaft line’s opposite ends, one at free end of the crankshaft and second at end of generator’s shaft. In the article is presented description of the measurement system and explanation of its mode of work. Experiments were based at two kinds of malfunction possible to be simulated at test bed. First one was simulation of a leak of fuel injection pump, the second one relayed on mounting of sets of injection valves with different nozzles characteristics (spraying nozzle angle), giving different parameters of fuel injection. Presented results of experiment derives from test cycle carried out using laboratory stand of Gdynia Maritime University equipped with 3- cylinder self − ignition engine, powering electric generator.

14

A novel predictive fuzzy adaptive controller for a two-mass drive system

Serkies P.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2018

|

Vol. 66, nr 1

37--47

EN

In the paper, a novel control structure based on the fuzzy logic and model predictive control methodologies for an elastic two-mass drive system is proposed. In order to reduce the computational requirements of the classical MPC methodology, the multi parametric programming (MPT) approach is used. The robustness of the system is ensured by implementation of three MPT controllers generated for different operation points and a supervisory fuzzy system. The main goal of the fuzzy system is suitable shaping of the control signal. The effectiveness of the proposed approach is checked in simulation and experimental tests. In order to show the properties of the proposed control structure, a critical comparison with an adaptive classical MPC controller is carried out. Both control structures are tested taking into account the performance and possibility of real-time implementation.

15

Optimal tuning of mechanical systems by application of a pneumatic tuner of torsional oscillation

Homišin J.

Zeszyty Naukowe. Transport / Politechnika Śląska

|

2017

|

z. 97

47--55

EN

Reducing the dynamic load of any mechanical system can be achieved when the torsional vibration magnitude is optimized by applying a pneumatic tuner of torsional oscillation. Changing the torsional stiffness of a pneumatic tuner can be accomplished by changing the pressure of the gaseous medium, out of operation or during the operation of a mechanical system. This results in two suggested methods of tuning: (i) tuning of torsional oscillating mechanical systems that are out of operation, which fulfils the conditions for mechanical system tuning; (2) tuning mechanical systems during an operation in a steady state, thus ensuring the conditions of so-called continuous tuning of the given systems. The aim of this paper is to present the possibility of controlling torsional oscillation of a mechanical system that is out of operation by applying a tangential pneumatic tuner of torsional oscillation.

16

Harmonic analysis of torsional vibration force excitation

Urbanský M.

Zeszyty Naukowe. Transport / Politechnika Śląska

|

2017

|

z. 97

181--187

EN

In our department, we deal with various methods for the continuous tuning of torsional oscillating mechanical systems during their operation, mainly in terms of torsional vibration magnitude. Therefore, in order to carry out necessary experimental research, we need torsional oscillation exciters, which operate on various principles. The objective of this paper is to conduct a harmonic analysis of a torsional oscillation force excitation mechanism, in order to identify the possibilities of its application.

17

Vibrations in Marine Power Transmission System

Doan D., Murawski L.

Zeszyty Naukowe Akademii Morskiej w Gdyni

|

2017

|

nr 100

37--50

EN

Vibration analyses of marine machines and structures are one of the most important during the design process as well as during exploitation. Vibrations of ship hull (including superstructure and main engine body) are separately analysed from the vibrations of power transmission system. Vibrations of propulsion system include three types: lateral vibration, coupled axial vibration and torsional vibration. Among them, torsional vibrations are usually the most dangerous for the shaft line and the crankshaft. These vibrations may cause the increasing failure of the engine crankshaft as broken and bent shaft. Therefore, this article focuses on the study of torsional vibration of ship propulsion system. Calculation of torsional vibration of propulsion system with a medium-speed main engine is presented. The analysis is based on finite element method, with the code written in Matlab software. The result of this paper is applied for the tugboat with the engine of power 350 HP.

PL

Analizy drgań okrętowych maszyn i konstrukcji są jednymi z najważniejszych podczas procesu projektowania oraz ich eksploatacji. Drgania kadłuba statku (z nadbudówką i korpusem silnika głównego włącznie) są analizowane oddzielnie od drgań układu przeniesienia napędu. Wyróżnia się trzy typy drgań układu napędowego: drgania giętne, sprzężone wzdłużne oraz skrętne. Wśród nich drgania skrętne są zwykle najgroźniejsze dla linii wałów wału korbowego. Mogą one zwiększyć prawdopodobieństwo uszkodzenia wału korbowego poprzez jego złamanie lub wygięcie. Z tego powodu w artykule skupiono się na analizie drgań skrętnych okrętowych układów napędowych. Zaprezentowano obliczenia drgań skrętnych układu napędowego wyposażonego w średnioobrotowy silnik główny. Analizę przeprowadzono metodą elementów skończonych, której procedura została napisana w programie Matlab. Zastosowano ją do obliczeń holownika wyposażonego w silnik o mocy 350 HP.

18

The effect of damping coefficients on the torsional vibration of the damped multi-branch gears system

Firouzi J., Ghassemi H., Vakilabadi K. A., Khalilnezhad H.

Journal of Applied Mathematics and Computational Mechanics

|

2017

|

Vol. 16, nr 4

5--16

EN

The effect of the damping coefficients has been considered to estimate the torsional vibration of the multi-branch gears systems. In this paper, the effect of the viscous damping between the gears and the fluid in which the gear is working and the effect of the structural damping of the shafts in a three-branched gear system is investigated. Initially, the governing equations were derived and then the damping effects were studied using MATLAB code. In order to validate the results which prepared by MATLAB code are compared with the other computational methods. To investigate the effects of the stiffness and damping on the shafts and gears, different gear branch systems are considered. Some of the vibration results on the damped gear branched systems with viscous damper and structural damper are analyzed and discussed.

19

Firing order selection for a V20 commercial diesel engine with FEV Virtual Engine

Buczek K., Lauer S.

Combustion Engines

|

2017

|

R. 56, nr 2

64--70

EN

The continuously increasing mechanical and thermal loads of modern engines require optimization of the designs with incorporation of a wide range of different aspects. Application of advanced computer simulations in the development process for most engine components is well established, leading to the creation of well optimized products. However, the optimization of such design variables ike the firing order, which influences engine operation in several disciplines, is still challenging. Considering the ever increasing peak firing pressure requirements, the layout of the firing order in multi-cylinder commercial engines is an efficient way to reduce crank train / overall engine vibration and main bearing loads, whilst controlling engine balancing and preserving adequate gas exchange dynamics. The proposed general firing order selection process for four-stroke engines and, in particular, its first part being the optimization of the firing order based on crank train torsional vibration, is the main topic of this paper. The exemplary study for a V20 high speed commercial Diesel engine regarding the influence of the firing sequence on crank train torsional vibration has been conducted with the multibody dynamics simulation software “FEV Virtual Engine”. It addresses various engine crankshaft layouts and engine applications.

20

An analysis of the self-excited torsional vibrations of the electromechanical drive system

Konowrocki R., Szolc T.

Vibrations in Physical Systems

|

2016

|

Vol. 27

187--194

EN

This paper presents a dynamic analysis of torsional vibrations of the railway drive system. A dynamic electromechanical drive model has been created and then integrated with the railway wheelset-rail system to simulate self-excited torsional vibrations of the considered system. Results of this analysis are used in order to investigate the drive system’s sensitivity to torsional oscillations. Here, the dynamic electromechanical interaction between the electric driving motor and the rotating wheelset is considered. This investigation has proved that the torsional stiffness and damping of drivetrain system strongly affect amplitudes of the selfexcited vibrations. A self-excited vibrations affecting on an energy consumption of the electric motor of the considered system are studied.