A very simple model based on the Quadrupole method was used in thetheoretical analysis of thermal diffusivity of composite materials of Cu-PVC, PVC-Cu-PVC, andCu-PVC-Cu. The use of MATLAB software with a return to rea...A very simple model based on the Quadrupole method was used in thetheoretical analysis of thermal diffusivity of composite materials of Cu-PVC, PVC-Cu-PVC, andCu-PVC-Cu. The use of MATLAB software with a return to real space using the Stehfest algorithm makesthe time of calculation very short. The thermal responses on the rear face of each consideredsample, which determine the thermal diffusivity were represented. A mathematical demonstration whichconfirmed the results was given. Thermal diffusivity determined from the rear face thermalresponses were compared with the results of the thermal diffusivity calculated by considering thecomposite materials to be homogeneous, and a discussion on the two kinds of results was provided.展开更多
Based on the theories of the heat transfer, the principle of phase transformation and the theory of electric and magnetic field, the mathematical model of transient temperature field involving phase transformation dur...Based on the theories of the heat transfer, the principle of phase transformation and the theory of electric and magnetic field, the mathematical model of transient temperature field involving phase transformation during magnetic field quenching is established. The heat exchange equation including magnetic field is founded. The finite element equation is set up. The distributing of transient temperature on the coupling effects of heat and magnetism is obtained. With test and measurement, the results show that after magnetic field quenching, cooling velocity is decreased, cooling curve is flatten out, and the hardness is slightly raised.展开更多
The purpose of this paper is to devise a new model of heat conduction for a body which istotally insulated at its boundary. The essence of the new model is modification of the Fourier law insuch a way that the resulti...The purpose of this paper is to devise a new model of heat conduction for a body which istotally insulated at its boundary. The essence of the new model is modification of the Fourier law insuch a way that the resulting heat conduction problem will be fonnulated as an initial value problemwith a nonstandard partial differential equation. The values of normal derivatives of the heat fiuxto various orders for all tmies (t> 0) will be detemined by the governing partial differential equa-tion and the values of normal derivatives of fluxes at the initial time (t=0). We study the properitesof this model and demonstrate its validity for a simple onedimensional case of a thin bar insulatedat both ends.展开更多
基金The research work is financially supported by National Natural Science Foundation of China (No.50276003).
文摘A very simple model based on the Quadrupole method was used in thetheoretical analysis of thermal diffusivity of composite materials of Cu-PVC, PVC-Cu-PVC, andCu-PVC-Cu. The use of MATLAB software with a return to real space using the Stehfest algorithm makesthe time of calculation very short. The thermal responses on the rear face of each consideredsample, which determine the thermal diffusivity were represented. A mathematical demonstration whichconfirmed the results was given. Thermal diffusivity determined from the rear face thermalresponses were compared with the results of the thermal diffusivity calculated by considering thecomposite materials to be homogeneous, and a discussion on the two kinds of results was provided.
文摘Based on the theories of the heat transfer, the principle of phase transformation and the theory of electric and magnetic field, the mathematical model of transient temperature field involving phase transformation during magnetic field quenching is established. The heat exchange equation including magnetic field is founded. The finite element equation is set up. The distributing of transient temperature on the coupling effects of heat and magnetism is obtained. With test and measurement, the results show that after magnetic field quenching, cooling velocity is decreased, cooling curve is flatten out, and the hardness is slightly raised.
文摘The purpose of this paper is to devise a new model of heat conduction for a body which istotally insulated at its boundary. The essence of the new model is modification of the Fourier law insuch a way that the resulting heat conduction problem will be fonnulated as an initial value problemwith a nonstandard partial differential equation. The values of normal derivatives of the heat fiuxto various orders for all tmies (t> 0) will be detemined by the governing partial differential equa-tion and the values of normal derivatives of fluxes at the initial time (t=0). We study the properitesof this model and demonstrate its validity for a simple onedimensional case of a thin bar insulatedat both ends.
