Abstract
Hydromagnetic effects are analyzed on flow and heat transfer over a horizontal surface placed in an externally squeezed free stream. The unsteady governing momentum and energy equations are transformed to similarity equations for certain families of the controlling parameters. It is found that both local wall shear stress and local Nusselt number increase as squeezing free stream velocity increases. Also, local Nusselt number is found to increase by an increase in the magnetic parameter. Further, the local wall shear stress is observed to increase as the magnetic parameter increases. Finally, hydromagnetic and suction wall permeable velocity (for permeable surfaces) effects are found to enhance the temperature or the concentration near the sensor surface. Thus, they enhance the detection capability of the sensor as long as the chemical binding at the sensor surface is not suppressed by increases in flow associated with these effects. (C) 2003 Elsevier Ltd. All rights reserved.