The thesis report covers some of the issues involving the atmospheric vortices, namely the tornado. It starts off with an introduction to atmospheric vortices and tornadoes. The terminology of vortex and vorticity are discussed in the introduction. Two theories of how tornado is formed are presented.
A number of experiments conducted in the past are reviewed in the following chapters. The experiments conducted had several objectives which included under what conditions would enable the development of concentrated vortices. Studies were conducted to find out how two and three-cell structures could develop from a one-cell structure. Investigations were also carried out to study the boundary effects on concentrated vortices. Experiments were also conducted to find out the behaviour of tornado-like vortices of under what circumstances it produced a vortex breakdown. Then, a simple numerical model was used to analyse vortex development in a flow configuration which largely simulated the key features of a severe tornadic storm system. A variety of magnitudes of the multiple-vortex phenomena seen in atmospheric vortices were summarised. The effects of convection cell geometry were explored which was previously ignored. The effects of boundary conditions on the numerically simulated vortices were also explored. Measurements of the axial pressure in two-celled vortices were conducted and the results were analysed to find out how it affected the axial momentum balance.
The data is extracted and presented in the report. The report gives an introduction to all the experiments and researches presented. Formulations and assumptions are described in the report. The procedures for the experiments are also presented. Results from the experiments are then discussed. Finally, a summary and conclusion is made.