Free convection boundary-layer flow of a micropolar fluid from a vertical flat plate

We examine theoretically the steady free convection from a vertical isothermal flat plate immersed in a micropolar fluid. The governing non-similar boundary-layer equations are derived and are found to involve two material parameters, K and n. These equations are solved numerically using the Keller-box method for a range of values of both parameters. A novel feature of the numerical solution is that the boundary layer develops a two-layer structure far from the leading edge. This structure is analysed using asymptotic methods and it is shown that there are two different cases to be considered, namely when n ≠ ½ and when n = ½. The agreement between the numerical results and the asymptotic analysis is found to be excellent in both cases. The present paper enables a complete description of the flow to be made for all values of K and n, and for all distances from the leading edge for which the boundary-layer approximation is valid.