The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
Huarong Tang - One of the best experts on this subject based on the ideXlab platform.
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transmission loss prediction on a single inlet double outlet cylindrical Expansion Chamber muffler by using the modal meshing approach
Applied Acoustics, 2008Co-Authors: X.j. Wang, Huarong TangAbstract:Abstract This work formulates the acoustical performance prediction on a single-inlet/double-outlet cylindrical Expansion-Chamber muffler. Expressions for the transmission loss (TL) of the muffler are formulated by using the modal meshing approach and the plane wave theory, respectively. The parametric influence upon the values of TL for this kind of muffler is numerically analyzed for various cases of length–diameter ratio, and the computed results of TL are compared to present the higher order mode effects. The results by the modal meshing approach are also compared with the finite element method to verify its accuracy.
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Transmission loss prediction on a single-inlet/double-outlet cylindrical Expansion-Chamber muffler by using the modal meshing approach
Applied Acoustics, 2008Co-Authors: X.j. Wang, Huarong TangAbstract:Abstract This work formulates the acoustical performance prediction on a single-inlet/double-outlet cylindrical Expansion-Chamber muffler. Expressions for the transmission loss (TL) of the muffler are formulated by using the modal meshing approach and the plane wave theory, respectively. The parametric influence upon the values of TL for this kind of muffler is numerically analyzed for various cases of length–diameter ratio, and the computed results of TL are compared to present the higher order mode effects. The results by the modal meshing approach are also compared with the finite element method to verify its accuracy.
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Transmission loss prediction on SIDO and DISO Expansion-Chamber mufflers with rectangular section by using the collocation approach
International Journal of Mechanical Sciences, 2007Co-Authors: X.j. Wang, Huarong TangAbstract:This paper presents the acoustical performance prediction on single-inlet/double-outlet (SIDO) and double-inlet/single-outlet (DISO) Expansion-Chamber mufflers with rectangular section. Expressions for the transmission loss (TL) of this kind of mufflers are formulated by using the collocation approach. Numerical results of TL are compared with the plane wave theory to show up the higher-order mode effects. Furthermore, the finite element method (FEM) is also employed again to verify its accuracy in view of these configurations of muffler.
Joseph Gannon - One of the best experts on this subject based on the ideXlab platform.
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Front-end electronics for PHENIX time Expansion Chamber
2001 IEEE Nuclear Science Symposium Conference Record (Cat. No.01CH37310), 2001Co-Authors: Kenneth Barish, O. Dietzsch, T. Ferdousi, Joseph Gannon, Jerald Harder, Achim Franz, S Y Fung, J. Fried, W C Chang, A KandasamyAbstract:Front-end electronics (FEE) has been developed for the PHENIX time Expansion Chamber (TEC), a multi-wire tracking detector with over 20k readout channels. The FEE for the TEC consists of an analog preamplifier shaping amplifier circuit board, a digital front-end module circuit board plus ancillary support boards for timing, control and communication. Signals from each Chamber wire are sampled (/spl sim/40 MHz), digitized, buffered, and then formatted as 64 channel serial data packets to be transmitted via 1 GHz optical link. Three custom IC's have been designed for this system: 1) octal preamplifier and shaping amplifier with tail cancellation and dual-gain for large dynamic range with full serial control of gain, shaping time and tail; 2) nonlinear 5 bit flash-ADC with 9 bit dynamic range; 3) digital memory unit for programmable delay and memory depth. The FEE has been installed, commissioned and operated in the PHENIX experiment at Brookhaven National Laboratory.
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the phenix time Expansion Chamber
Nuclear Physics, 1999Co-Authors: M Rosati, O. Dietzsch, T. Ferdousi, Achim Franz, Kenneth Barish, S Y Fung, W C Chang, S Botelho, A L De Gogoi, Joseph GannonAbstract:Abstract The TEC/TRD subsystem will track all charged particles and contribute to the particle identification by the measurement of energy loss. The design, construction and testing of the TEC Chambers are described.
Ml Munjal - One of the best experts on this subject based on the ideXlab platform.
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Effect of wall thickness on the end corrections of the extended inlet and outlet of a double-tuned Expansion Chamber
Applied Acoustics, 2010Co-Authors: P Chaitanya, Ml MunjalAbstract:Simple Expansion Chambers, the simplest of the muffler configurations, have very limited practical application due to the presence of periodic troughs in the transmission loss spectrum which drastically lower the overall transmission loss of the muffler. Tuned extended inlet and outlet can be designed to nullify three-fourths of these troughs, making use of the plane wave theory. These cancellations would not occur unless one altered the geometric lengths for the extended tube in order to incorporate the effect of evanescent higher-order modes (multidimensional effect) through end corrections or lumped inertance approximation at the area discontinuities or junctions. End corrections of the extended inlet and outlet have been studied by several researchers. However the effect of wall thickness of the inlet/outlet duct on end correction has not been studied explicitly. This has significant effect on the tuning of an extended inlet/outlet Expansion Chamber. It is investigated here experimentally as well as numerically (through use of 3-D FEM software) for stationary medium.
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Transmission loss analysis of rectangular Expansion Chamber with arbitrary location of inlet/outlet by means of Green's functions
Journal of Sound and Vibration, 2009Co-Authors: B Venkatesham, Mayank Tiwari, Ml MunjalAbstract:Transmission loss of a rectangular Expansion Chamber, the inlet and outlet of which are situated at arbitrary locations of the Chamber, i.e., the side wall or the face of the Chamber, are analyzed here based on the Green's function of a rectangular cavity with homogeneous boundary conditions. The rectangular Chamber Green's function is expressed in terms of a finite number of rigid rectangular cavity mode shapes. The inlet and outlet ports are modeled as uniform velocity pistons. If the size of the piston is small compared to wavelength, then the plane wave excitation is a valid assumption. The velocity potential inside the Chamber is expressed by superimposing the velocity potentials of two different configurations. The first configuration is a piston source at the inlet port and a rigid termination at the outlet, and the second one is a piston at the outlet with a rigid termination at the inlet. Pressure inside the Chamber is derived from velocity potentials using linear momentum equation. The average pressure acting on the pistons at the inlet and outlet locations is estimated by integrating the acoustic pressure over the piston area in the two constituent configurations. The transfer matrix is derived from the average pressure values and thence the transmission loss is calculated. The results are verified against those in the literature where use has been made of modal Expansions and also numerical models (FEM fluid). The transfer matrix formulation for yielding wall rectangular Chambers has been derived incorporating the structural–acoustic coupling. Parametric studies are conducted for different inlet and outlet configurations, and the various phenomena occurring in the TL curves that cannot be explained by the classical plane wave theory, are discussed.
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transmission loss analysis of rectangular Expansion Chamber with arbitrary location of inlet outlet by means of green s functions
Journal of Sound and Vibration, 2009Co-Authors: B Venkatesham, Mayank Tiwari, Ml MunjalAbstract:Transmission loss of a rectangular Expansion Chamber, the inlet and outlet of which are situated at arbitrary locations of the Chamber, i.e., the side wall or the face of the Chamber, are analyzed here based on the Green's function of a rectangular cavity with homogeneous boundary conditions. The rectangular Chamber Green's function is expressed in terms of a finite number of rigid rectangular cavity mode shapes. The inlet and outlet ports are modeled as uniform velocity pistons. If the size of the piston is small compared to wavelength, then the plane wave excitation is a valid assumption. The velocity potential inside the Chamber is expressed by superimposing the velocity potentials of two different configurations. The first configuration is a piston source at the inlet port and a rigid termination at the outlet, and the second one is a piston at the outlet with a rigid termination at the inlet. Pressure inside the Chamber is derived from velocity potentials using linear momentum equation. The average pressure acting on the pistons at the inlet and outlet locations is estimated by integrating the acoustic pressure over the piston area in the two constituent configurations. The transfer matrix is derived from the average pressure values and thence the transmission loss is calculated. The results are verified against those in the literature where use has been made of modal Expansions and also numerical models (FEM fluid). The transfer matrix formulation for yielding wall rectangular Chambers has been derived incorporating the structural–acoustic coupling. Parametric studies are conducted for different inlet and outlet configurations, and the various phenomena occurring in the TL curves that cannot be explained by the classical plane wave theory, are discussed.
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Time-domain analysis of extended-tube Expansion Chamber mufflers by means of the method of characteristics
2002Co-Authors: M. C. Manna, Ml Munjal, S. HaldarAbstract:Accurate prediction of pressure pulsations in an engine is required because of the fact that these pulsations affect the engine performance and are the prime noise generators in the 1C engine. There are two methods to analyze the exhaust system and these are: (i) time domain analysis, and fit) frequency-domain analysis. The second one is more convenient, but it lacks self-dependency. It requires prior knowledge of the source characteristics, evaluation of which is a challenge to the researchers. On the contrary, the first one is self-dependent and it provides a complete formalism to analyze the exhaust system. In this article, a computer program has been developed considering different boundary conditions for simple Expansion-Chamber muffler and extended-tube Expansion-Chamber muffler for the two-characteristics as well as the three-characteristics model. The results obtained by the present two methods have been compared with each other.
M Rosati - One of the best experts on this subject based on the ideXlab platform.
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the phenix time Expansion Chamber
Nuclear Physics, 1999Co-Authors: M Rosati, O. Dietzsch, T. Ferdousi, Achim Franz, Kenneth Barish, S Y Fung, W C Chang, S Botelho, A L De Gogoi, Joseph GannonAbstract:Abstract The TEC/TRD subsystem will track all charged particles and contribute to the particle identification by the measurement of energy loss. The design, construction and testing of the TEC Chambers are described.
Kenneth Barish - One of the best experts on this subject based on the ideXlab platform.
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Front-end electronics for PHENIX time Expansion Chamber
2001 IEEE Nuclear Science Symposium Conference Record (Cat. No.01CH37310), 2001Co-Authors: Kenneth Barish, O. Dietzsch, T. Ferdousi, Joseph Gannon, Jerald Harder, Achim Franz, S Y Fung, J. Fried, W C Chang, A KandasamyAbstract:Front-end electronics (FEE) has been developed for the PHENIX time Expansion Chamber (TEC), a multi-wire tracking detector with over 20k readout channels. The FEE for the TEC consists of an analog preamplifier shaping amplifier circuit board, a digital front-end module circuit board plus ancillary support boards for timing, control and communication. Signals from each Chamber wire are sampled (/spl sim/40 MHz), digitized, buffered, and then formatted as 64 channel serial data packets to be transmitted via 1 GHz optical link. Three custom IC's have been designed for this system: 1) octal preamplifier and shaping amplifier with tail cancellation and dual-gain for large dynamic range with full serial control of gain, shaping time and tail; 2) nonlinear 5 bit flash-ADC with 9 bit dynamic range; 3) digital memory unit for programmable delay and memory depth. The FEE has been installed, commissioned and operated in the PHENIX experiment at Brookhaven National Laboratory.
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the phenix time Expansion Chamber
Nuclear Physics, 1999Co-Authors: M Rosati, O. Dietzsch, T. Ferdousi, Achim Franz, Kenneth Barish, S Y Fung, W C Chang, S Botelho, A L De Gogoi, Joseph GannonAbstract:Abstract The TEC/TRD subsystem will track all charged particles and contribute to the particle identification by the measurement of energy loss. The design, construction and testing of the TEC Chambers are described.
