Abstract
This paper deals with the hydromagnetic flow of an electrically conducting fluid due to an oscillating flat plate of perfect conductor in the presence of transverse magnetic field. Exact solutions for arbitrary values of R (the Reynolds number), Rm (the magnetic Reynolds number) and S (the magnetic pressure number) are first derived and then some special cases are discussed corresponding to limiting values of the parameters S and Rm in order to clarify the hydromagnetic effect, and especially an interesting special case corresponding to the ‘magnetic Stokes approximation’ is discussed in some detail.
Next, the drag on the plate is calculated for both cases of non-conducting plate and perfectly conducting plate. It is found that, in both cases, the amplitudes of the total drag (shear-stress+Maxwell’s stress) always increase and the initial phases of the total drag are always retarded for any values of R, Rm and S compared with those of the well-known classical case, i.e., the case of no magnetic field and/or electrical conductivity of the fluid being zero.
