The Experts below are selected from a list of 723 Experts worldwide ranked by ideXlab platform
L Vita - One of the best experts on this subject based on the ideXlab platform.
-
identification of modal damping ratios of four Flue Chimney of a thermoelectrical plant using pseudo inverse matrix method
Structural Design of Tall and Special Buildings, 2009Co-Authors: M Cavacece, Pier Paolo Valentini, L VitaAbstract:Some computational issues related to the identification of modal parameters of structures are presented in this paper. Optimal estimation of modal parameters often requires the solution of an overdetermined linear system of equations. Hence the computation of a pseudo-inverse matrix is involved. In this paper the numerical performance of different algorithms for Moore–Penrose pseudo-inverse computation have been tested for modal analysis of a four-Flue Chimney of a thermoelectrical plant. The computational scheme herein adopted for parameter identification is based on well-known modal properties and has a fast rate of convergence to solution. The computation of the Rayleigh damping coefficients a and b is an important step in the area of the modal superposition technique. The proposed approach can accurately predict damping ratios and all the eigenvectors without evaluating mass and stiffness matrices. Copyright © 2007 John Wiley & Sons, Ltd.
M R Mokhtarzadehdehghan - One of the best experts on this subject based on the ideXlab platform.
-
numerical study of buoyant plumes from a multi Flue Chimney released into an atmospheric boundary layer
Atmospheric Environment, 2002Co-Authors: Carola S Konig, M R MokhtarzadehdehghanAbstract:Abstract A numerical study has been carried out of three-dimensional, full-scale, turbulent, buoyant plumes from a four-Flue Chimney in an atmospheric boundary layer. The simulations were based on the k−e turbulence model and a finite-volume method. The investigation was aimed to verify the question of how closely the overall characteristics of merged plumes from a multi-Flue Chimney match those of an equivalent single plume. Therefore, the results for multi-Flue plumes were compared with those for a single plume under the same release conditions for volume flow rate, momentum and temperature. The differences in the velocity, temperature and turbulence energy fields of a single plume and multiple plumes were mainly significant in the early stages of rise and spreading. The multiple plumes merged very quickly and by ten diameters downstream only small differences between the plumes’ cross-sections could be distinguished. Comparisons of the rise heights showed that the arrangement of the individual Flues within the Chimney, with respect to the cross-wind, affects the rise height of the merged plumes. One of the multi-Flue cases, which allowed the cross-wind penetration between the adjacent plumes, resulted in a lower rise height of the merged plume, while one other case, which provided a greater shielding, led to a rise height which was in agreement with the plume from the single-Flue Chimney. The rise heights were compared with empirical data.
Carola S Konig - One of the best experts on this subject based on the ideXlab platform.
-
numerical study of buoyant plumes from a multi Flue Chimney released into an atmospheric boundary layer
Atmospheric Environment, 2002Co-Authors: Carola S Konig, M R MokhtarzadehdehghanAbstract:Abstract A numerical study has been carried out of three-dimensional, full-scale, turbulent, buoyant plumes from a four-Flue Chimney in an atmospheric boundary layer. The simulations were based on the k−e turbulence model and a finite-volume method. The investigation was aimed to verify the question of how closely the overall characteristics of merged plumes from a multi-Flue Chimney match those of an equivalent single plume. Therefore, the results for multi-Flue plumes were compared with those for a single plume under the same release conditions for volume flow rate, momentum and temperature. The differences in the velocity, temperature and turbulence energy fields of a single plume and multiple plumes were mainly significant in the early stages of rise and spreading. The multiple plumes merged very quickly and by ten diameters downstream only small differences between the plumes’ cross-sections could be distinguished. Comparisons of the rise heights showed that the arrangement of the individual Flues within the Chimney, with respect to the cross-wind, affects the rise height of the merged plumes. One of the multi-Flue cases, which allowed the cross-wind penetration between the adjacent plumes, resulted in a lower rise height of the merged plume, while one other case, which provided a greater shielding, led to a rise height which was in agreement with the plume from the single-Flue Chimney. The rise heights were compared with empirical data.
M Cavacece - One of the best experts on this subject based on the ideXlab platform.
-
identification of modal damping ratios of four Flue Chimney of a thermoelectrical plant using pseudo inverse matrix method
Structural Design of Tall and Special Buildings, 2009Co-Authors: M Cavacece, Pier Paolo Valentini, L VitaAbstract:Some computational issues related to the identification of modal parameters of structures are presented in this paper. Optimal estimation of modal parameters often requires the solution of an overdetermined linear system of equations. Hence the computation of a pseudo-inverse matrix is involved. In this paper the numerical performance of different algorithms for Moore–Penrose pseudo-inverse computation have been tested for modal analysis of a four-Flue Chimney of a thermoelectrical plant. The computational scheme herein adopted for parameter identification is based on well-known modal properties and has a fast rate of convergence to solution. The computation of the Rayleigh damping coefficients a and b is an important step in the area of the modal superposition technique. The proposed approach can accurately predict damping ratios and all the eigenvectors without evaluating mass and stiffness matrices. Copyright © 2007 John Wiley & Sons, Ltd.
Pier Paolo Valentini - One of the best experts on this subject based on the ideXlab platform.
-
identification of modal damping ratios of four Flue Chimney of a thermoelectrical plant using pseudo inverse matrix method
Structural Design of Tall and Special Buildings, 2009Co-Authors: M Cavacece, Pier Paolo Valentini, L VitaAbstract:Some computational issues related to the identification of modal parameters of structures are presented in this paper. Optimal estimation of modal parameters often requires the solution of an overdetermined linear system of equations. Hence the computation of a pseudo-inverse matrix is involved. In this paper the numerical performance of different algorithms for Moore–Penrose pseudo-inverse computation have been tested for modal analysis of a four-Flue Chimney of a thermoelectrical plant. The computational scheme herein adopted for parameter identification is based on well-known modal properties and has a fast rate of convergence to solution. The computation of the Rayleigh damping coefficients a and b is an important step in the area of the modal superposition technique. The proposed approach can accurately predict damping ratios and all the eigenvectors without evaluating mass and stiffness matrices. Copyright © 2007 John Wiley & Sons, Ltd.