Effect of ion-slip current on the thermal instability of natural convection flow in a boundary layer flow past a horizontal flat plate.

Purpose – The purpose of this paper is to study the effects of ion-slip current and Hall current on the formation of longitudinal vortices in natural convection flow over a heated horizontal plate. Design/methodology/approach – The criterion on the position marking on the onset of longitudinal vortices is defined in the present paper. The results show that the onset position characterized by the Grashof number depends on the Prandtl number, the Reynolds number, the wave number, the Hall parameter, the ion-slip parameter, and the Hartmann number. Findings – The flow becomes more stable as the magnetic field increases. However, the destabilizing effect is found on the flow when the Hall and ion-slip currents are presented. Research limitations/implications – The standard method of linear stability model is applied, with terms higher than first order in disturbance quantities being neglected. Practical implications – The problem of MHD natural convection flow with Hall and ion-slip currents has many important engineering applications, e.g. power generators, Hall accelerators and flows in channels and ducts. Originality/value – This study is to check the validity of the assumptions that the conditions of Hall and ion-slip currents can be ignored. [ABSTRACT FROM AUTHOR]