Exact analysis of unsteady m. h. d. convective diffusion

Abstract

The paper presents an exact analysis of the dispersion of a solute in an electrically conducting fluid flowing between two parallel plates in the presence of a uniform transverse magnetic field. Using a generalized dis­persion model, which is valid for all time after the injection of the solute in the flow we evaluate the longitudinal dispersion coefficients as functions of time. For small values of the Hartmann number M , the values of the dispersion coefficients show rapid fluctuations which decay with increase in M , and for moderate and large values of M , these coefficients monotonically decrease with increase in M . In a non-conducting fluid, such rapid fluctuations are absent and the dispersion coefficients for a pipe flow are less than the corresponding values for a channel flow.