The class of system considered is a single degree of freedom undamped vibrating system with a clearance in which the dynamical behavior is described by a state-space representation in real time. The direct identific...The class of system considered is a single degree of freedom undamped vibrating system with a clearance in which the dynamical behavior is described by a state-space representation in real time. The direct identification technique for the estimate of a clearance and other parameters in the system is presented in terms of least squares method and step-by-step iteration approach. For numerical simulation purpose, the simulated data are achieved by corrupting the modeled responses. The mathematical algorithm, which is put forward, has proven to be effective through a practical numerical example.展开更多
A new local exhaust ventilation hood is presented. First, the test system inlaboratory room is established. Secondly a mathematical model is developed in terms of the stokesstream function, and the governing equation ...A new local exhaust ventilation hood is presented. First, the test system inlaboratory room is established. Secondly a mathematical model is developed in terms of the stokesstream function, and the governing equation is solved using finite-difference techniques. Theinjection flow of the exhaust hood is treated as a boundary condition of the main flow. Experimentsresults well agree with the solution of theoretical prediction. The model can, therefore, be used todesign this kind of Aaberg hood. Thirdly the important parameters affecting the performance ofAaberg exhaust hood are taken into account. In the mean time the connection of these parameters isdeduced by multivariate linear regression based on the experimental results. The work is usefulwhether in designing this kind of local ventilation Aaberg exhaust hood or in predicting the hood'swork performance.展开更多
文摘The class of system considered is a single degree of freedom undamped vibrating system with a clearance in which the dynamical behavior is described by a state-space representation in real time. The direct identification technique for the estimate of a clearance and other parameters in the system is presented in terms of least squares method and step-by-step iteration approach. For numerical simulation purpose, the simulated data are achieved by corrupting the modeled responses. The mathematical algorithm, which is put forward, has proven to be effective through a practical numerical example.
文摘A new local exhaust ventilation hood is presented. First, the test system inlaboratory room is established. Secondly a mathematical model is developed in terms of the stokesstream function, and the governing equation is solved using finite-difference techniques. Theinjection flow of the exhaust hood is treated as a boundary condition of the main flow. Experimentsresults well agree with the solution of theoretical prediction. The model can, therefore, be used todesign this kind of Aaberg hood. Thirdly the important parameters affecting the performance ofAaberg exhaust hood are taken into account. In the mean time the connection of these parameters isdeduced by multivariate linear regression based on the experimental results. The work is usefulwhether in designing this kind of local ventilation Aaberg exhaust hood or in predicting the hood'swork performance.
