dynamo n. 1.【電學(xué)】發(fā)電機(jī)〔尤指直流發(fā)電機(jī)〕。 2.〔口語〕勤奮肯干的人,精力充沛的人。 an alternating [direct] current dynamo 交[直]流發(fā)電機(jī)。 a compound [wound] dynamo 復(fù)繞[復(fù)激發(fā)]電機(jī)。 shunt [wound] dynamo 分繞[并勵(lì)發(fā)]電機(jī)。
Many planets ( for example, ganymede, mercury, the earth, jupiter and saturn ) and stars ( for example, the sun ) possess intrinsic magnetic fields . the explanation for their existence and variation remains a great challenge to planetary scientists and astrophysicists . this article attempts to review some recent developments and difficulties in the study of magnetohydrodynamics for the electrically conducting fluid interiors of planets and stars . it is the fluid motions, usually driven by thermal convection, that generate and sustain magnetic fields through magnetohydrodynamic processes in planets and stars . in planets, the magnetohydrodynamic processes are strongly affected by the combined and inseparable effects of rotation, magnetic fields and spherical geometry . the key dynamics involves the interaction between the coriolis and lorentz forces . in the sun, it is the solar tachocline, a thin shear flow layer located at the base of the convection envelope, that plays an essential role in the solar magnetohydrodynamic processes which produce the 11-year sunspot cycle . some results of a new nonlinear three-dimensional solar dynamo model are also presented 許多行星(如木衛(wèi)三,水星,地球,木星和土星)和恒星(如太陽)具有內(nèi)部磁場.對這些磁場的存在和變化的解釋對行星科學(xué)家和天體物理學(xué)家是一個(gè)巨大的挑戰(zhàn).本文試圖總結(jié)行星和恒星的導(dǎo)電流體內(nèi)部磁流體力學(xué)研究的新近發(fā)展和困難.一般由熱對流驅(qū)動的流動通過磁流體力學(xué)過程產(chǎn)生并維持在行星和恒星中的磁場.在行星中磁流體力學(xué)過程強(qiáng)烈地受到轉(zhuǎn)動,磁場和球幾何位型的綜合影響.其動力學(xué)的關(guān)鍵方面涉及科里奧利力和洛倫茲力間的相互作用.在太陽中其流線,即處于對流層的薄的剪切流層在太陽的磁流體力學(xué)過程中扮演了一個(gè)基本的角色,并由之產(chǎn)生了11年的太陽黑子周期.本文也給出了一個(gè)新的非線性三維太陽發(fā)電機(jī)模型