Nonsimilar solutions in thermomicropolar fluid boundary layer

Abstract

A boundary layer analysis has been presented for the momentum and heat transfer characteristics of a thermomicropolar fluid flowing through a channel which consists of a portion with parallel walls (velocity U 0 and wall temperature T 0) followed by either a convergent ( a < 0) or a divergent ( a > 0) section. The boundary layer solutions relate to the potential flow given by U( x) = U 0 − ax which, evidently, constitutes a generalised form of the flow along a flat plate and becomes identical with it when a = 0. The solutions are obtained in the form of a power series in x∗ (=ax/U 0) (x∗ < 0 , accelerated flow, x∗ > 0, decelerated flow). For both the accelerated and decelerated flows the thermomicropolar fluid boundary layer characteristics such as velocity, microrotation rate, temperature, skin friction, wall couple stress, and Nusselt number have been presented either graphically or in tubular form for several values of the material parameters and thermal parameters of the fluid. A comparison with the corresponding results for a Newtonian fluid reveals that the microelements present in the fluid reduce the velocity and frictional drag, increase the boundary layer temperature, cool the boundary and enhance flow separation.