Date of Award
Doctor of Philosophy
The boundary layer formed on the outer surface of a semi-infinite circular cylinder in steady axial incompressible flow is studied in this thesis. Governing equations are solved using local similarity techniques and a nonsimilar numerical approach.;Two obvious similarity transformations can be used to obtain solutions for this problem, but they do not yield the same results, since the flow is essentially nonsimilar. In the extreme case that the radius of the cylinder is much larger than the boundary layer thickness, only one of the transformation leads to the correct solution, i.e., the Blasius solution. The other transformation yields an axial velocity profile which is deceptively close to the Blasius. This is also strongly suggested by comparing the series expansions of axial velocity profiles from each transformation. Solutions obtained by using either transformation merge at downstream locations.;Since the use of a single similarity variable does not solve the problem in its full range, an overall numerical solution is obtained by applying Keller's Box method with primitive variables and similarity coordinates. Similarity coordinates scale the axial and radial coordinates such that boundary layer growth does not appear explicitly as we move downstream. Thus, the numerical mesh does not need to be enlarged and this leads to increased efficiency in computation. Results are obtained in the range that start with the Blasius solution and proceed far downstream.;A local similarity method, which is very efficient, using primitive variables with similarity coordinates is also applied to obtain solutions that are valid over a wide range of the flow.;Results obtained by these methods compare well with previously obtained analytical and numerical solutions, but they extend considerably the range of solution.
Sawchuk, Stephen P., "Circular Cylinder In Axial Flow" (1990). Digitized Theses. 2002.