The scope of this thesis involved the determination of the effects of vortices on the downstream flow at exit from a pulsed jet. It has been observed through experiments on such flows that the decay rate of peak velocity across a section of fluid flow follows a form of exponential decay. Furthermore at some distance beyond the fluid entry point this decay rate changes. This thesis aims, through computational (vortex) methods, to provide a better understanding how vortex dynamics can describe these processes. The actions by which this goal was achieved are as follows:
A detailed decomposition of the problem was made to provide an understanding of the specific purpose of this thesis.
An initial study of the basic numerical foundations derived from governing laws for vortex dynamics and boundary layer theory was sought to understand the methods by which an appropriate solution may be obtained. Such laws, introduced in later chapters, provide for analysing local vorticity within a flow and following its progression downstream and interactions.
With this research complete, a method for the solution to the task at hand was found. While direct comparisons with real flows have been made, unfortunately, results do not appear to consistently correlate with the computational method employed. There exist a number of reasons for these differences, the most obvious of which results from the time step limits employed during simulation.
For the user, a program has been provided which is capable of solving most fluid dynamic problems including both laminar and turbulent regimes. For the future program developer, a guide has been established to the techniques available in vortex dynamics, and a base program code developed.