Stability of free convection flow over a vertical uniform flux plate.

1) For given H the heat transfer decreases when the viscoplastic effect, i.e., yQB, rises, whereas it increases with (a -{j#i) for given yOB. This means that the magnetic field can "control" the heat exchange, operating in the inverse way of the dynamic gradient (a + fti). 2) When a magnetic field is applied, the first-order contribution of cf becomes explicitly dependent on B, rather than only on Re /(a -f fa) (as in the nonmagnetic case), and increases with B. This is a significant effect of the magnetic field whose presence makes the contributions of cf also of the first order affected by the viscoplastic behavior. Such influence is increasing with //, and it results in