Three-dimensional darcian free convection near a stagnation point on an isothermal surface

The unsteady free convection boundary-layer flow in a fluid-saturated porous medium near a general three-dimensional stagnation point is considered. It is shown that the problem can be reduced to an equivalent two-dimensional problem by a simple transformation of variables. The form of solution then depends only on the sign of the quantity a + b, where a and b are the principal curvatures of the body at the stagnation point.