ABSTRACT
This chapter presents methods to solve problems with two independent variables involving second-order differential equation and first-kind boundary condition. The problems fall in the category of partial differential ones. These are a very important class of transport phenomena problems, and it will be very useful to demonstrate the applications of several analytical and approximate mathematical methods. One is interested to know the drag force applied by the fluid on the plate and vice versa. Of course, this is the most simplified situation of unsteady state regime of the common problem of resistance to the movement of bodies in fluids. However, its fundamentals are useful and are applied to complex problems in the naval, automobile, and airplane industries, not to mention pipes, mixers, and all sorts of equipment or systems where relative movement of fluids and solid surfaces occur. Just one condition regarding time and two involving the vertical direction are required to completely define the boundary value problem.
