Dissertation > Excellent graduate degree dissertation topics show

Acoustic Wave Propagation in Non-Uniform Medium

Author: TianXiaoPei
Tutor: JinZuo
School: Zhejiang University
Course: Electromagnetic Field and Microwave Technology
Keywords: acoustic wave propagation non-uniform medium finite element method temperature gradient
CLC: O422
Type: Master's thesis
Year: 2011
Downloads: 331
Quote: 0
Read: Download Dissertation

Abstract


Acoustic wave propagation through non-uniform medium has a very wide application. Using principle of acoustic propagation in an inhomogeneous medium, The acoustic thermometer, acoustic leak detectors and acoustic cleaning device has been widely used in the real world.In order to study the sound propagation in non-uniform media accurately, this paper builds the model of the finite element method (FEM) and studies acoustic wave propagation in one-dimension non-uniform media, study the effect of the frequency of sound, the incident angle, temperature distribution profile in the medium on reflection coefficient mostly, at the same time they are optimized for a certain goal.The propagation of planar sound waves through non-uniform medium regions may undergo substantial modification. Gas temperature gradients in the non-uniform gas region were believed to be the primary cause for wave modification. Analytical solutions of Helmholtz equation for plane sound transmission were obtained in gas waveguide with non-uniform media density along the sound propagation direction. We study sound wave propagation in two-dimension non-uniform media on base of one-dimension model, one hand, according to the Helmholtz equation in the idea conditions, we use variational methods to get the FEM equation, then solve the equation through making programming, the other hand, we used software to simulate sound propagation in the non-uniform medium waveguide and compared the results with that obtained by programming, found that these results were comparable.Finally, on the basic of the result that acoustic frequency, non-uniform dielectric thickness and the temperature gradient have an effect on the coefficient of sound wave propagation, the channel structure adapting for propagation of sound wave was optimized.

Related Dissertations

  1. Research on the Structure and Characteristics of Permanent Magnetic Coupling,TH139
  2. Simulation Analysis on Temperature Stress of RCC Arch Dam and Its Construction Joints Design Research,TV642.2
  3. Stability Analysis of Roller Compacted Concrete Gravity Dam Based on Time-history Method,TV642.2
  4. Research on Intelligent Aerial Bomb for Forest Fire Fighting,S762
  5. Study of Modal Characteristics of a Car Body-in-White,U463.82
  6. Studies on Wind-induced Dynamic Response and Vibration Control of Guyed Cat-head Transmission Tower-line System,TM753
  7. Decision Design and Research on Moving-iron Linear Oscillatory Motor with Two Separated Stators,TM359.4
  8. Analysis of Rotor Temperature Field of Hydro Generator on Asymmetric Operation Condition,TM312
  9. Study of the Method in Modeling and Simulation of Vehicle Ride Comfort,U461.4
  10. Scrap copper smelting furnace temperature measurement method,TF811
  11. Rerearch on Thermal Underwater Glider Experiment Basin and Design of the Glider,V277
  12. Vehicle-mounted snubbing workover rig derrick Design and analysis,TE935
  13. Particle reinforced copper matrix composites mechanical behavior of finite element analysis,TB331
  14. Based on FEM / BEM walled hull structural vibration and sound radiation characteristics of,U661.44
  15. Small aperture glass-ceramics based on helium-neon laser fundamental transverse mode selected experimental study,TN248
  16. Absorption spectroscopy based on open -line measurement of the ambient temperature and variable pressure CO 2 component measurement,O657.3
  17. The Numerical Simulation of the Steel Slag Which is as a Large Volume of Foundation Filler in Panzhihua Iron and Steel Company,TU521.4
  18. Research in the Physical Features of Adjustable Micro-Strured Fiber Bragg Grating,TN253
  19. Hamiltonian System and Semi-analytical Method Approach to Bending Problem of Piezoelectric Cantilever Beam,O241.82
  20. The Finite Element Simulation of Complex Structure,O327
  21. Study on Temperature Effect of Porous Cement Concrete Pavement,U416.216

CLC: > Mathematical sciences and chemical > Physics > Acoustics > Sound propagation
© 2012 www.DissertationTopic.Net  Mobile