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1

The resonance expansion system for emissions reduction of internal combustion engines

Tarbajovský Pavol, Puškár Michal

Zeszyty Naukowe. Transport / Politechnika Śląska

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2023

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z. 119

279--289

EN

One of the main problems of today’s automotive manufacturers are emission norms that are getting much stricter. According to these high demands, car manufacturers are developing new systems to keep exhaust emissions at the lowest possible level. The resonance expansion system for emissions reduction of internal combustion engines could decrease emissions production not only in modern vehicles but also in older vehicles by additional mounting on the exhaust system. This article shows the resonance expansion system technical solution and simulations of fluid flow done in flow simulation software. The resonance expansion system is also patented, and further experiments for design improvement are planned in the near future.

2

Analysis of the Influencing Factors of the Acoustic Performance of the Muffler Considering Acoustic-structural Coupling

Zhao Bo, Li He

Archives of Acoustics

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2022

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Vol. 47, No. 4

479--490

EN

In the calculation of the acoustic performance of mufflers, the walls of mufflers are usually treated rigidly without considering the acoustic-structural coupling, but the results so calculated differ significantly from the actual situation. Based on the basic equations, the article derives the finite element equations of the muffler system while considering the acoustic-structural coupling effect and theoretically analyses the connection between the acoustic-structural coupling system and the structural and acoustic modes. The structural and acoustic modes of the muffler are calculated and the reasons for the mutation of the transmission loss curve of the muffler when the acoustic-structural coupling is considered are analysed. The results show that the acoustic-structural coupling is the result of the interaction between the structure and the air inside the expansion chamber under acoustic excitation, which manifests mutations in the sound pressure inside the muffler in some frequency bands. Then, using a single-chamber muffler as an example, the transmission loss is used to characterise the performance of the muffler. The effects of different factors such as shell thickness, structure, porous media material lining, and restraint method on the acoustic-structural coupling effect of the muffler are analysed, and the structure of a double-chamber muffler is successfully optimised according to the conclusions.

3

Process of manufacturing a tailpipe shape by cold forming in automotive industry

Bałon Paweł, Cieślik Jacek, Halama Łukasz, Kiełbasa Bartłomiej, Lach Tomasz, Lesiński Marcin, Łajczak Dominik, Rejman Edward, Smusz Robert

Przegląd Mechaniczny

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2020

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nr 6

31--35

EN

Cold forming and shaping processes of elements that are part of car chassis assemblies, due tovisual and mechanical parameters (springback effect), cause problems in the production of this type of geometric shapes. It significantly reduces the production capacity due to the need to create many tools that are time consuming and expensive to manufacture. For this reason, the topic of winding the shape of a tailpipe for the automotive industry, depending on the geometric requirements, has been taken up, which allows both unit production and serial production depending on customer requirements.

PL

Procesy formowania i kształtowania na zimno elementów wchodzących w skład zespołów podwozia samochodowego, ze względu na parametry wizualne i mechaniczne (efekt sprężynowania), powodują problemy w produkcji tego typu elementów. Zmniejsza to znacznie możliwości produkcyjne ze względu na konieczność tworzenia wielu narzędzi, których produkcja jest czasochłonna i kosztowna. Z tego powodu podjęto temat kształtowania na zimno rury wydechowej dla przemysłu motoryzacyjnego, w zależności od wymagań geometrycznych, co umożliwia zarówno produkcję jednostkową, jak i seryjną w zależności od wymagań klienta.

4

A method of producing car mufflers by wrapping sheet metal

Bałon Paweł, Cieślik Jacek, Halama Łukasz, Kiełbasa Bartłomiej, Lach Tomasz, Lesiński Marcin, Łajczak Dominik, Rejman Edward

Mechanik

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2020

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R. 93, nr 5-6

6--9

EN

The cold pressing of deep-drawing steel parts of a car muffler encounters blank quality problems, i.e. springback. For this reason, the stamping tool requires compensation of the springback effect by using additional operations, e.g. by calibration. The paper focuses on testing the method of forming processes by wrapping sheet metal on a special tool using servo drives, gears and crankshaft to exert pressure.

PL

Tłoczenie na zimno głęboko tłocznych stali, które stosuje się na części tłumików samochodowych, napotyka problemy związane z jakością wytłoczki, tj. ze sprężynowaniem. Z tego względu narzędzie tłoczące wymaga kompensacji efektu sprężynowania poprzez wykonanie dodatkowych operacji, np. kalibracji. W pracy badano metodę formowania, polegającą na obróbce bezubytkowej przez zawijanie blachy na specjalnym przyrządzie oraz urządzeniu wykorzystującym serwonapędy, przekładnię i wał korbowy do wywierania nacisku.

5

Evaluation of the transmission and the scattering matrix applicability to the mufflers analysis

Snakowska Anna, Gorazd Łukasz, Jurkiewicz Jerzy

Vibrations in Physical Systems

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2019

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Vol. 30, nr 1

art. no. 2019102

EN

The analysis of the acoustical systems can be carried out based on a number of different formalisms, of which applied frequently are the transfer matrix formalism, in which the chosen state variables are the sound pressure p and the sound velocity v, and the scattering matrix formalism adopting the sound pressures p+ and p− and the sound velocities v+ and v− of waves propagating through an element in both directions. Even though, they are mathematically equivalent, i.e. there exists the unequivocal transformation from one to another there are some advantages and disadvantages in applying one or the other to analyse mufflers or other acoustic system, especially when the propagation of a multimode wave is assumed and numerical calculations are indispensable. In the paper the transformation between the formalisms has been derived and applied to analyse the phenomena at a junction between the tail pipe and the chamber and also in mufflers composed of one or two chambers. The more flexible for numerical calculations seems the scattering matrix formalism, especially when the number of propagating modes differs on both sides of a junction. On the other hand the transmission matrix formalism is suitable for analysing systems constituting a cascade. The sources of the advantages and disadvantages of both formalisms are explained. The results obtained can be helpful in the effective design of silencers with specific properties.

6

Review on Resonator and Muffler Configuration Acoustics

Khairuddin M. H., Said M. F. M., Dahlan A. A., Kadir K. A.

Archives of Acoustics

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2018

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Vol. 43, No. 3

369--384

EN

Nowadays, resonators are widely used in automobile, industrial applications, aerospace engineering, and some other fields. One of the unique characteristics of resonators which made them highly convenient is their acoustic capability to attenuate noise without having to use any acoustic absorptive material. The device acts by manipulating the sound waves to create mismatch impedance. Recent studies also suggest that the typical bulk size resonator with narrow frequency bandwidth is not the only option anymore, since there are newly designed resonators that are capable of having wide attenuation bandwidth and are smaller in size. Numerical and experimental measures were executed accordingly with the same purpose to obtain efficient noise attenuation results from varying resonators’ and mufflers’ configuration in terms of quantity, types, and geometry. The aim of this review is to summarize recent developments on resonator study and to try highlighting some noteworthy issues that need to be unraveled by future research. Helmholtz resonator, Quarter wave tube, Herschel-Quincke tube and helicoidal resonator are part of the numerous resonator studies that will be covered in this paper.

7

Proposal of the combined exhaust gas heat exchanger and the muffler

Brezáni M., Baran P., Labuda R.

Diagnostyka

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2015

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Vol. 16, No. 3

73--78

EN

The article discusses about the design of a combined exhaust gas heat exchanger with muffler. The first stage deals with the calculation of the exhaust gas heat exchanger according to the required parameters. The next step addresses the structural design of the exhaust gas heat exchanger according to the parameters of the calculation. Subsequently creation a 3D model, which will be used for the simulation of flow of the working substance in the heat exchanger and heat transfer simulation of the media. The simulations are solved in a 3D simulation program COMSOL Multiphysics 5.0. Further solves the structural design of muffler, which will form a part of the exhaust gas heat exchanger. Subsequently execution of the measurements on the real model of the combined exhaust gas heat exchanger to verify the accuracy of calculations, simulations and structural designs.

PL

W artykule omówiono projekt zintegrowanego wymiennika ciepła spalin wraz z tłumikiem. Pierwszy etap dotyczył obliczania wymiennika ciepła spalin w zależności od wymaganych parametrów. Następnym krokiem było stworzenie projektu konstrukcyjnego wymiennika ciepła spalin według parametrów z obliczeń. Następnie stworzono model 3D, który był wykorzystany do symulacji przepływu substancji roboczej w wymienniku ciepła oraz do symulacji transferu ciepła mediów. Symulacje są wykonywane w programie do symulacji 3D - COMSOL Multiphysics 5.0. Dalej wykonano projekt konstrukcyjny tłumika, tworzący całość z wymiennikiem ciepła spalin. Następnie wykonano pomiarów na rzeczywistym obiekcie zintegrowanego wymiennika ciepła spalin z tłumikiem, w celu sprawdzenia poprawności obliczeń, symulacji i projektu konstrukcyjnego.