Đang chuẩn bị liên kết để tải về tài liệu:
Thermodynamics Kinetics of Dynamic Systems Part 2

Tham khảo tài liệu 'thermodynamics kinetics of dynamic systems part 2', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Some Thermodynamic Problems in Continuum Mechanics 19 3.5 Materials with static magnetoelectric coupling effect In this section we discuss the electro-magneto-elastic media with static magnetoelectric coupling effect shortly. For these materials the constitutive equations are C.V ữer _ m. oVe.p p _ 1 oi m.ppPT ơkl - Cijkl ij - ejklEj - ejklHj - V2 lijklEiEj - V2 lijklHiHj - km EmEl - kmHmHl - PkmHmEl - p mEmHl Dk - Ál lijkl ij ml mk mk ml El e i PklHl Bk -pik l lmkl ij 2 amỉl mk arn.k ml Hl e i PklEl where Pij - Pji is the static magnetoelectric coupling coefficient. The electromagnetic body couple is still balanced by the asymmetric stress i.e. DkEl - DlEk BkHl - BlHk km El- m Ek Em VkmHl - lmHk Hm flkmEl - PlmEk Hm PkmH - PmHk Em - 2 k l In this case though the constitutive equations are changed but the electromagnetic Gibbs free energy ge in Eq. 56b governing equations 66 69 and the Maxwell stress 64 are still tenable. 4. Conclusions In this chapter some advances of thermodynamics in continuum mechanics are introduced. We advocate that the first law of the thermodynamics includes two contents one is the energy conservation and the other is the physical variational principle which is substantially the momentum equation. For the conservative system the complete governing equations can be obtained by using this theory and the classical thermodynamics. For the nonconservative system the complete governing equations can also be obtained by using this theory and the irreversible thermodynamics when the system is only slightly deviated from the equilibrium state. Because the physical variational principle is tensely connected with the energy conservation law so we write down the energy expressions we get the physical variational principle immediately and do not need to seek the variational functional as that in usual mathematical methods. In this chapter we also advocate that the accelerative variation of temperature needs extra heat and propose the general inertial .