Coupled Field Analysis of a Chimney Used in Cement Industry

Chimney, which shape the ultimate factor of a machine using a flue fuel consisting of boiler, play a vital function in maintaining performance, draft, and many others, of a gadget and additionally in minimizing the atmospheric pollution. Metal chimneys also are called steel stacks. The metallic chimneys are product of metal plates and supported on basis. The steel chimneys are used to get away and disperse the flue gases to this sort of height that the gases do not contaminate surrounding. In this thesis, chimney can be designed thinking about dead load and wind load. The bureau of Indian requirements (BIS) layout codes techniques can be used for the design of the chimney. The chimney turned into considered as a cantilever beam with annular cross segment. 3-D version of the chimney is finished in pro/engineer and matched area analysis is accomplished on the chimney in ANSYS. A simplified model of chimneys with various thicknesses like 10mm, 12mm, 14mm and 16mm were modeled environment. Keywords: Chimney, Flue Gases, Coupled Field Analysis

Vibration and acoustic insulation properties of generalized phononic crystals

Based on the previous studies, the concept of generalized phononic crystals (GPCs) is further introduced into the cylindrical shell structures, and a type of cylindrical shells of generalized phononic crystals (CS-GPCs) is constructed. Subsequently, the structure field and acoustic-structural coupled field of that composite cylindrical shells are examined respectively in this paper. Considering the Bloch theorem is not capable of explaining the generalized periodic situation existing in this structure field, a new analysis method involving transferring matrix eigenvalue based on the mechanical state vector is proposed to calculate the energy band structure. Through observing the energy band structure, an obvious wave band gap is obtained when the elastic wave propagates in the CS-GPCs for modes with different order, whose forming mechanism includes two aspects, i.e., the wave front expansion effect and the Bragg scattering effect. In addition, we further explore the related influences of the longitudinal wave mode and shear wave mode in structure on these band gaps, and some conclusions are illustrated. For acoustic-structural coupled field, the expressions of the acoustic transmission coefficients for different modes are built, and the frequency responses are numerically calculated to verify the band gap characteristics of the CS-GPCs. Furthermore, the acoustic pressure distribution of the internal and external acoustic fields is also analyzed in detail, and the influence laws of the parameters (offset distance and frequency) of the line source on acoustical pressure distribution and its directivity are explored.

A Cylindrical Superelement for Thermo-Mechanical Analysis of Thin Composite Vessels

In this study, a new cylindrical shell superelement with trigonometric shape functions is developed. This element is formulated based on the classical theory of shells, and it is especially designed for coupled-field analysis of thin cylindrical vessels or tubes made of composite materials. As a case study, a thermo-mechanical analysis of a thin composite cylinder is conducted. By invoking to the uniform and non-uniform meshing, the deformation and the stress results are calculated and compared with the analytical solutions. At the end, the efficiency and accuracy of the proposed superelement is also depicted via comparison of the corresponding results with the ones which are calculated by means of shell elements and via a commercial software package.