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About: Muffler is a(n) research topic. Over the lifetime, 8209 publication(s) have been published within this topic receiving 42664 citation(s). more

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Journal ArticleDOI
01 Jan 2007-
Abstract: Testing was conducted on a prototype automobile exhaust thermoelectric generator (AETEG) installed in a 1999 GMC Sierra pick-up truck. The system consisted of the generator, its power conditioning unit, and the interfaces to the test truck's engine coolant and exhaust systems. The objective of the test was to measure the AETEG's performance and its effect on the truck systems as well as to determine which factors are important for optimizing an AETEG design. Testing was performed in a dynamometer-equipped wind tunnel at Delphi Corporation's Harrison Thermal Systems Division in Lockport, New York. The first tests established the benchmark data set. Then the prototype AETEG was installed and three configurations of the system were tested in succession: the AETEG alone, the AETEG with portions of the exhaust pipes leading to it insulated, and the AETEG with insulated upstream exhaust pipes and with a pre-cooling heat exchanger operating to lower the inlet coolant temperature to the generator. Some of the important outcomes of the tests were: insulating the exhaust and lowering the coolant temperature had a significant positive effect on the power, parasitic losses resulting from the AETEG weight and the coolant pumping power were significant but manageable, and the increased exhaust flow resistance and the additional heat load from the AETEG were not significant effects. more

165 citations

15 Oct 1992-
Abstract: A lean NOx reduction catalyst capable of reducing NOx through reaction of H 2 with NOx at low temperatures below 350° C. is installed in a downstream portion of an exhaust pipe of an internal combustion engine in or near a muffler. Such an NOx reduction catalyst comprises, for example, Pt/zeolite catalyst. An H 2 generator is installed so as to supply the H 2 to an inlet side of the NOx reduction catalyst. The H 2 generator may include a reforming catalyst for reforming methanol, LPG, or natural gas to generate H 2 . The generated H 2 flows to the NOx reduction catalyst where it reacts with NOx to purify the exhaust gas. more

160 citations

Journal ArticleDOI
Abstract: A simple method is presented for modeling perforated muffler components such as concentric resonators with perforated flow tube, and expansion chambers and reverse flow chambers with perforated inlet and outlet tubes. The theory includes mean flow, but is confined to those configurations having one acoustically long dimension. It is based on a segmentation procedure in which each segment is described by a transmission matrix. The four‐pole parameters of a component are then found from the product of the transmission matrices. The four‐pole parameters for configurations having through flow, cross flow, and reverse flow are presented. Because the product matrices are dimensionally small and because no inversion is needed, computational time is much lower than other methods such as finite element or finite difference. This allows rapid and economical modeling to be performed where iterative solutions are required because of dominating finite amplitude effects, for example. more

144 citations

16 Jun 2006-
Abstract: The shaft (20) of an engine (19) is coupled to a turbine (28) of an organic Rankine cycle subsystem which extracts heat (45-48, 25) from engine intake air, coolant, oil, EGR and exhaust. Bypass valves (92, 94, 96, 99) control engine temperatures. Turbine pressure drop is controlled via a bypass valve (82) or a mass flow control valve (113). A refrigeration subsystem having a compressor (107) coupled to the engine shaft uses its evaporator (45a) to cool engine intake air. The ORC evaporator (25a) may comprise a muffler including pressure pulse reducing fins (121, 122), some of which have NOx and/or particulate reducing catalysts thereon. more

142 citations

Proceedings ArticleDOI
Z. Tao1, A. F. Seybert1Institutions (1)
05 May 2003-SAE transactions
Abstract: The most common approach for measuring the transmission loss of a muffler is to determine the incident power by decomposition theory and the transmitted power by the plane wave approximation assuming an anechoic termination. Unfortunately, it is difficult to construct a fully anechoic termination. Thus, two alternative measurement approaches are considered, which do not require an anechoic termination: the two load method and the two-source method. Both methods are demonstrated on two muffler types: (1) a simple expansion chamber and (2) a double expansion chamber with an internal connecting tube. For both cases, the measured transmission losses were compared to those obtained from the boundary element method. The measured transmission losses compared well for both cases demonstrating that transmission losses can be determined reliably without an anechoic termination. It should be noted that the two-load method is the easier to employ for measuring transmission loss. However, the two-source method can be used to measure both transmission loss and the four-pole parameters of a muffler. more

134 citations

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Topic's top 5 most impactful authors

Min-Chie Chiu

35 papers, 391 citations

ML Munjal

35 papers, 439 citations

Ying-Chun Chang

19 papers, 223 citations

Francisco D. Denia

10 papers, 275 citations

Tamer Elnady

9 papers, 62 citations