Using a point vortex approximation and delta-regularization Krasny ( 1986 ) obtained a smooth roll-up of a vortex sheet into a double branched spiral.
12.
The spontaneous loss of analyticity in a vortex sheet is a consequence of mathematical modeling since a real fluid with viscosity, however small, will never develop singularity.
13.
Continuous approximation of a vortex sheet by vortex panels with arc wise diffusion of circulation density also shows that the sheet rolls-up into a double branched spiral.
14.
Alternatively, calculated from the flowfield perspective ( far-field approach ), the drag force comes from three natural phenomena : shock waves, vortex sheet, and viscosity.
15.
A "'vortex sheet "'is a term used in fluid mechanics for a surface across which there is a normal component of the flow velocity is continuous.
16.
However, the propellers are operating in a turbulent airflow in the pusher configuration ( due to airflow past the wings moving aft in vortex sheets ) and high-velocity exhaust gasses are discharged directly into the propellers, thus making them noisier than they would be in a tractor configuration.
17.
In fluid dynamics, a "'K�rm�n vortex street "'( or a "'von K�rm�n vortex sheet "') is a repeating pattern of swirling singing " of suspended telephone or power lines, and the vibration of a car antenna at certain speeds.
