Calculation of the acoustic radiation field at the surface of a finite cylinder by the method of weighted residuals

1969 ◽  
Vol 57 (3) ◽  
pp. 291-306 ◽  
Author(s):  
F.H. Fenlon
Keyword(s):  
Radiation Field ◽  
Acoustic Radiation ◽  
Finite Cylinder ◽  
Weighted Residuals ◽  
Method Of Weighted Residuals

ON THE ACOUSTIC RADIATION FIELD OF THE PIEZO-ELECTRIC OSCILLATOR AND THE EFFECT OF VISCOSITY ON TRANSMISSION: PART II

1934 ◽  
Vol 11 (4) ◽  
pp. 484-488 ◽  
Author(s):  
L. V. King
Keyword(s):  
Radiation Field ◽  
Sea Water ◽  
Acoustic Radiation ◽  
Wave Length ◽  
Numerical Data ◽  
Transmission Part ◽  
Coefficient Of Viscosity ◽  
Theoretical Results ◽  
Piezo Electric

Numerical data on the distance of transmission of sound in sea water from a 10-in. piezo-electric oscillator are discussed in the light of theoretical results obtained in a previous paper. It is shown how by the principle of similitude the chart for transmission at optimum wave-length calculated for a 50-watt, 60 cm. oscillator can be used for a transmitter of any given diameter and output. A comparison with some experiments of Boyle's points to the fact that at supersonic frequencies, in the neighborhood of 100,000 cycles, a considerably higher coefficient of viscosity than that obtained by flow methods must be used.

Modeling of a Urea SCR Catalyst With Automotive Applications

2002 ◽  
Author(s):  
Devesh Upadhyay ◽  
Michiel Van Nieuwstadt
Keyword(s):  
Catalytic Reduction ◽  
Chemical Properties ◽  
Lumped Parameter Model ◽  
Scr Catalyst ◽  
Weighted Residuals ◽  
Method Of Weighted Residuals ◽  
Lumped Parameter ◽  
1D Model ◽  
Continuously Stirred Tank Reactor ◽  
Three State Model

A zero order lumped parameter control oriented model of a Selective Catalytic Reduction (SCR) catalyst is presented. The lumped parameter model is developed using two approaches. in the first approach it was assumed that the catalyst behaves as an Isothermal Continuously Stirred Tank Reactor (ICSTR). The second approach involved deriving the lumped parameter model from a 1D model using the method of weighted residuals. Both approaches led to a three state model, with the gas phase concentrations of NOx and NH3 and the surface coverage fraction as the states. The model depends on chemical properties specific to the SCR catalyst; consequently model validation requires knowledge of these parameters, either via laboratory-based experiments or as supplied by the catalyst supplier. We present an alternate approach that allows estimation of the essential parameters through a minimization of the l2 errors between measured and simulated results.

Research on Vibro-Acoustic Characteristics of Underwater Finite Plate-Shell Structure under Multiple Excitations

2013 ◽  
Vol 834-836 ◽  
pp. 1351-1359
Author(s):  
Yong Yong Zhu
Keyword(s):  
Shell Structure ◽  
Acoustic Radiation ◽  
Radiation Power ◽  
Acoustic Vibration ◽  
Finite Cylinder ◽  
Acoustic Characteristics ◽  
Theory Of Plates ◽  
Plates And Shells ◽  
Vibration Coupling ◽  
Finite Cylindrical Shell

An analysis based on the first kind of Lagranges equations was presented for investigating the vibration and acoustic radiation of underwater finite cylindrical shell with interior plate under multiple excitations. The strain energy and kinetic energy of cylinder and plate were gained by the theory of plates and shells, and the potential energy of excitation and fluid loading was found based on acoustic-vibration coupling, and the connection conditions of plate and cylinder were expressed by Lagrange multipliers, then the vibro-acoustic equations of finite cylinder with interior plate under shafting excitation were established. The influences of excitations and plates position to the vibro-acoustic characteristics were studied by the equations. The results show that the frequency components of plate-shell structure are more complex. For the double excitations on plate, the distance between excitations is larger, the average velocity and sound radiation power are lower, while the radiation efficiency is larger. The modeling and analytical methods adopted in this paper are also available for more complex composite structure.

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