Physical simulation of a single-celled tornado-like vortex, Part A: Flow field characterization

Tornado vortex simulation is described and a new simulator is presented. Radial, tangential, and vertical velocity measurements together with surface static pressure measurements are presented and compared with available data from the Manchester and Spencer, South Dakota tornadoes of May 30, 1998, and June 24, 2003, respectively. Comparisons of the surface pressure profile and tangential velocity decay showed good agreement with the TTU simulation. Analytically, the simulated velocity decay is found to be similar to that of a modified Rankine combined vortex with a variable exponent that changed with height. The simulator is demonstrated as a viable device for determining wind loading on building models in tornado-like vortex flows, and such results are presented in Part B.