Abstract: Numerous research projects in automotive engineering focus on the industrialization of the thermoelectric generator (TEG) The development and the implementation of thermoelectric systems into the vehicle environment are commonly supported by virtual design activities In this paper a customized simulation architecture is presented that includes almost all vehicle parts which are influenced by the TEG (overall system simulation) but is nevertheless capable of real-time use Moreover, an optimized planar TEG with minimum nominal power output of about 580 W and pressure loss at nominal conditions of 10 mbar, synthesized using the overall system simulation, and the overall system simulation itself are used to answer a generally neglected question: What influence does the position of a TEG have on the back pressure of the subsequent exhaust gas system of the vehicle? It is found that the influence of the TEG on the muffler is low, but the catalytic converter is strongly influenced It is shown that the TEG can reduce the back pressure of an exhaust gas system so much that its overall back pressure is less than the back pressure of a standard exhaust gas system

Abstract: PROBLEM TO BE SOLVED: To provide a forced air-cooling engine work machine, in which cooling performance is improved in both of forced air cooling of a muffler during operation of the engine and natural air cooling of the muffler during an engine stopSOLUTION: A muffler storage chamber is disposed with a heat-shield plate 40 interposed between a muffler 30 and a muffler cover 6 The muffler cover 6 is provided with a cooling air inlet 37a for introducing a part of cooling air generated by a cooling fan into the muffler storage chamber to cool the muffler, and with a discharge outlet for discharging the air after cooling The inside of the muffler storage chamber is divided into two segments to form: a forced air-cooling chamber 42 that is a space for guiding the cooling air introduced through the cooling air inlet 37a to a cooling air outlet; and a natural air-cooling chamber 43, which is provided with an outside air inlet 40a and guides outside air introduced through the outside air inlet to the discharge outlet The outside air inlet 40a is formed at a bottom of the heat-shield plate 40; and the discharge outlet is disposed near an upper end of the muffler storage chamber and near an exhaust port 38

Abstract: In these review paper different types of mufflers and design of exhaust system belonging engine has been studied. The object of this study is decide muffler design which one reduces a large amount of noise level and back pressure of engine. In designing, there is different parameter which has to taken in to the consideration. These parameters affect the muffler efficiency.

Abstract: An IC engine is a major source of noise pollution, where exhaust noise play major contribution. That is why the reduction of exhaust noise from engines is an important issue. A muffler in the exhaust pipe is used for reducing noise. Muffler requires specific design considering various noise parameters. In this the tunable resonator is used whose length can be varied by using a piston that can be set at different positions. Noise level is also measured at the different positions of resonator to check the effect of variation of length of silencer that shows the smaller the resonator size better is insertion loss. A muffler for stationary petrol engine (engine test rig) has been designed. Sound level is measured before and muffler installation at different position of resonator piston & the effect of resonator length is studied.

Abstract: During its operation, a refrigerator compressor produces pulsating noise, primarily driven by the suction and discharge processes. Sound attenuating mufflers need to be designed without any additional pressure drop on both suction and discharge side. Higher pressure drop at the suction and discharge side will lead to lower charging and discharging of the compressor and hence reduces cooling capacity. Since a one dimensional formulation with plane wave assumption to calculate transmission loss is not applicable for small mufflers (ratio of length to diameter is less than 1), a numerical methodology was established and validated using an impedance tube transmission loss measurement. Detailed three dimensional Computational Fluid Dynamics (CFD) simulations were used to further study the pressure drop across the mufflers for a given flow and compressor operating frequency. In the proposed methodology, acoustic pressure distribution inside the chamber is observed as a function of frequency and an optimal position of inlet and outlet pipes is decided to improve transmission loss. Different muffler design options were evaluated and also discussed possible acoustic performance and pressure drop improvements. Mufflers designed with this approach showed better acoustic performance on the suction and discharge side of refrigerator compressor. The effect of different working fluids on acoustic frequencies is also studied, which would additionally help in tuning the muffler to improve its effectiveness.

Abstract: Mufflers have been widely used in the exhaust system to reduce the noise. However, installing muffler may deteriorate the efficiency due to the increase of back pressure. Mufflers usually consist of partition plates and perforated holes in a expansion chamber. In this paper, the influences of the location of the partition and hole on the acoustic TL and back pressure were examined. The acoustic TL was predicted using virtual lab commercial software, while the back pressure were predicted using CFX commercial software. The results were used to set up a database for finding their trends. The optimal muffler model in user-interested frequency range could be selected by analyzing this database.

Abstract: For an automotive exhaust system the noise level, transmission loss & back pressure are the most important parameters for the driver & engine performance. In order to improve the design efficiency of muffler, resonating of the exhaust muffler should be avoided by its natural frequency. Mufflers are most important part of the engine system and it is commonly used in the exhaust system to minimize the sound transmission level which is caused by exhaust gases. The design of muffler becomes more and more important for noise reduction. The solid modeling of exhaust muffler is created by CATIA-V5 and modal analysis is carried out by ANSYS to study the vibration and natural frequency of muffler. So as to differentiate between the working frequency from natural frequency and avoid resonating..

Abstract: Presently, there existed in industrial plants broadband noise hybridized with pure tones. In order to overcome a pure tone noise with a high peak value that is harmful to human hearing, a traditional reactive muffler has been used. However, the traditional method for designing a reactive muffler has proven to be time-consuming and insufficient. Helmholtz mufflers that deal with a pure tone have been adequately researched. However, manufacturing costs for the Helmholtz resonator have been too expensive. Noise elimination of pure tones for side-branched resonators (SBRs) that are easily manufactured has also been addressed. Nevertheless, the shape optimization of multi-chamber side-branched mufflers that deal with a broadband noise hybridized with multiple tones has been mostly ignored. In order to efficiently reduce the peak noise level, interest in shape optimization of a side-branched muffler is coming to the forefront. That being so, an analysis of the sound transmission loss (STL) and the best optimize...

Abstract: In many industries, muffler and silencer design is primarily accomplished via trial and error . Prototypes are developed and tested, or numerical simulation (finite or boundary element analysis) is used to assess the performance. While these approaches reliably determine the transmission loss, designers often do not understand why their changes improve or degrade the muffler performance. Analyses are time consuming and models cannot be changed without some effort. The intent of the current work is to demonstrate how plane wave muffler models can be used in industry . It is first demonstrated that plane wave models can reliably determine the transmission loss for complicated mufflers below the cutof f frequency. Some tips for developing dependable plane wave models are summarized. Moreover, it is shown that plane wave models used correctly help designers develop intuition and a better understanding of the effect of their design changes.

Abstract: In a muffler for a compressor and a compressor having the same according to the present disclosure, an integral formation of a suction noise unit and a discharge noise unit may reduce the number of components for configuring a suction side muffler and a discharge side muffler so as to reduce a leakage of a refrigerant generated at an assembled portion of the muffler and also reduce a suction passage and a discharge passage in length. Also, the division between the suction noise unit and the discharge noise unit may prevent a discharged refrigerant from heating a sucked refrigerant, which may result in a reduction of a suction loss. The formation of the suction noise unit and the discharge noise unit using a plastic material may result in a reduction of fabricating costs. In addition, the structures of the suction side noise space and the discharge side noise space may be simplified and noise removal effect can be increased using the suction chamber and the discharge chamber. This may result in a reduction of an entire size of the muffler and improvement of the noise effect.

Abstract: An underbody trim for the rear-end region of a motor vehicle conceals a rear exhaust muffler. For the purposes of cooling the rear exhaust muffler, an air inlet is provided in the underbody trim. The air inlet is arranged in a region in which, while the motor vehicle is traveling, a pressure is higher at the underside of the underbody trim than the region of the floor panel arranged thereabove. Cooling ambient air is thus conducted into the region of the rear exhaust muffler with low flow losses.

Abstract: In recent years the automotive industry has been using an increasing number of high powered engines with fewer cylinders, with the goal to reduce weight and fuel consumption and hence to achieve lower CO2 emissions. Following, an overview about the currently existing methods and products within the exhaust development is given which follow automotive lightweight trend. Continuous innovations in new materials, structural design and manufacturing process as well as mastering the integration of the components and modules within the system with a thorough understanding and optimization of the system behavior is enabling the reduction of weight in exhaust system. Another possibility to reduce the weight is the use of additional components such as valves. In the following, a discussion about the different types of valves is presented. These valves can be implemented within the exhaust system in order to bring a constraint in the system and consequently additional acoustic damping. Due to engine downsizing, many premium vehicles lost their class-representing sound signature. An active system can be used in order to enhance the sound according to the customer demands. In addition to that, an active system can help reducing muffler volume.

Abstract: So as to improve the noise reduction performance and the optimization efficiency of the muffler, an optimization design method based on acoustic transfer matrix and genetic algorithm was proposed in this paper, wherein the transmission loss at certain frequency was treated as the optimization objective, and each structural dimension of the muffler as the design variable, the structural optimization design was conducted through genetic algorithm, thus the optimal solutions were eventually obtained; Moreover, single objective optimization and multiple objective optimization were successively performed, with the results compared with each other, through which it could be demonstrated that the result of the latter was superior to that of the former, concretely, the noise was reduced by 2132 dB

Abstract: In one or more embodiments, a muffler shield includes a shield body extending in a longitudinal direction and defining a middle portion positioned between first and second side portions along a transverse direction, a cross-section of the middle portion and at least one of the first and second side portions respectively defining a middle profile and a side profile shorter than the middle profile.

Abstract: The thermoelectric generator (TEG) recovering waste heat from the exhaust has became a potential technical issue, due to its characters of pollution-free, no moving parts, reliability and high efficiency. There exist arrangement on the chassis and the exhaust backpressure of whole system will increase of these two problems, when integrating TEG in the car of TEG and the muffler is to integrate the thermoelectric module on the surface muffler, it can effectively reduce the size of TEG, also reduce its weight and structural complexity. It also reduced the backpressure of TEG, meanwhile solved the compatibility issues with other components of exhaust system. The structural integration laid the foundation to achieve the large-scale use of thermoelectric materials in the car.

Abstract: At present, the control of the automobile engine exhaust noise is mainly installed exhaust muffler. Muffler design and performance research mainly around the silencing performance and the influence to engine power loss. This article built the 3d modeling of automobile exhaust muffler and through simulation analysis obtained the muffler internal acoustic pressure distribution and changes of insertion loss with frequency. Predict the silencer muffler performance as well as the influence on engine power loss. Provide a reference basis for the design of the silencer and optimization. Compared to the traditional experiment method, the method in this article has the advantages of short cycle, low cost.

Abstract: The invention discloses a high-frequency muffler used on an automobile intercooler intake pipe. The high-frequency muffler comprises a high-frequency muffling structure and a main pipeline connected on the intercooler intake pipe; a closed shell is positioned and connected on the periphery of the main pipeline, at least two partitions are arranged in the closed shell radially to enable at least two resonant cavities and an expansion cavity to be formed in the closed shell, each resonant cavity is communicated with the main pipeline through a group of small round through holes formed in the circumference of the main pipeline, the expansion cavity is directly communicated with the main pipeline, and the resonant cavities and the expansion cavities jointly form the high-frequency muffling structure. In a limited engine room space, the high-frequency muffler is wider in muffling frequency band, excellent in muffling performance and capable of more effectively lowering high-frequency noise such as squeal and surge generated in the working process of a turbocharger.

Abstract: The method involves defining high-performance operating range of an internal combustion engine based on rotational speed and torque of the internal combustion engine. The internal combustion engine is switched to an engine operation for a guard of an exhaust line in case of attaining high power operating range in context of increase in motor power. The internal combustion engine is throttled by a throttle device, so that exhaust mass flow through a turbine (5) of an exhaust gas turbocharger and/or boost pressure (PSR) are increased. An independent claim is also included for an engine control equipment.

Abstract: A double mode muffler that can automatically adjust the exhaust resistance according to the engine speed was designed. Based on computational fluid dynamics theory, the governing equation and turbulent equations for numerical simulation of muffler were established. The pressure loss and the internal flow characteristics of the double mode muffler were analyzed by CFD software. The influence of the distance between the main and sub-muffler on the flow field of exhaust system was researched. The internal pressure distribution, the turbulence intensity distribution and the velocity vector diagram of the dual mode muffler were obtained. The pressure loss of double mode muffler mainly distributes in the area of air mutations. Main silencer plays a leading role in the entire exhaust system. The trend of the pressure loss of the exhaust system with the change of the distance between main and auxiliary muffler was obtained. When the distance between the main and auxiliary silencer changed from 50 mm to 300 mm, the pressure loss of exhaust system muffler increases first and then decreases, and then continue to increase. The results will provide a theoretical basis for designing complex exhaust system.

Abstract: The utility model discloses a muffler mounting bracket. The muffler mounting bracket comprises a muffler connecting plate which is fixedly connected with a muffler, a frame connecting plate which is fixedly connected with a frame, and an elastic connecting body which connects the muffler connecting plate with the frame connecting plate. According to the muffler mounting bracket, the advantage of high pressure resistance of the elastic material is utilized to effectively avoid the phenomenon that vibration absorbing materials in the existing muffler bracket structure is pulled and broken, and therefore, the service life of the muffler bracket can be prolonged.

Abstract: 1 Institute of Materials, School of Materials Science and Engineering, Shanghai University, 149 Yanchang Road, Shanghai 200072, China 2 Stainless Steel Technical Centre, Research Institute, Baoshan Iron & Steel Co., Ltd., 580 Changjiang Road, Shanghai 200431, China 3 State Key Laboratory of Development and Application Technology of Automotive Steels (Baosteel Group), 885 Fujin Road, Shanghai 201900, China * E-mail: mouchengli@shu.edu.cn

Abstract: The main purpose of a muffler in an automobile is to reduce the engine noise. An automotive muffler is designed and modified to achieve attenuation and back pressure targets. Attenuation and back pressure characteristic of base muffler is altered by changing its internal configuration. The target value was set at the time of conceptual stage and to obtain these targets, the muffler internal construction is modified. The targeted value is a compromise between the transmission loss and the backpressure. CAE tools are used for simulating the environment to achieve targeted TL(Transmission Loss) and back pressure. Experimental test have been conducted to check and correlate with CAE results in order to evaluate the effect of muffler internal construction on both TL and backpressure.

Abstract: The utility model relates to a throttling diffusion compound muffler, comprising a rain cap, a gas outlet, a shell, lifting lugs, a resistive sound absorption body, a sound absorption layer, a hole injection device, a throttling pressure reduction device, liquid drain outlets, and a gas inlet. The shell is a cylindrical structure. The gas inlet is arranged in one end of the shell while the gas outlet is arranged in the other end of the shell. The internal end, close to the gas inlet, of the shell is equipped with the throttling pressure reduction device. The periphery of the throttling pressure reduction device is provided with the hole injection device. The periphery of the inner wall of the shell is provided with the sound absorption layer. The internal end, close to the gas outlet, of the shell is equipped with the resistive sound absorption body. The gas outlet is externally equipped with the rain cap. The external end, close to the gas outlet, of the shell is equipped with at least two lifting lugs symmetrically. The noise reduction amount reaches 50-60 dB, and the muffler is applicable to high temperature and high pressure environments. At the same time, the muffler has high strength and corrosion resistance and ensures the safety of a steam exhaust pipe during heat energy work to a certain extent. Moreover, the muffler is small in size, light in weight, convenient to mount, and easy to maintain.