EUROMECH 384 Colloquium on Steady and Unsteady Separated Flows Manchester, UK July 6-9 1998. Book of Abstracts

摘要

The numerical simulation of unsteady separated turbulent flows around moving lifting surfaces is fueled by the industrial need to analyse and understand flow phenomena associated with the behaviour of aircrafts during manoeuvres. The complex flow phenomena and interactions that occur during super- manoeuvrable, high-alpha flight are highly non-linear in nature and include the occurrence of strong suction pressures, rapid movement of the stagnation point, transition of the boundary layer, formation of separation bubbles. production of shocks and most of all generation of an energetic vortical structure, referred to as the dynamic-stall vortex (DSV) that, temporarily leads to a significant lift increase (see Figure 1). Numerical simulation of such phenomena appears to be a challenging task. The phenomenon of dynamic stall (DS) has been selected as an initial point for the present study. The DS process has been under investigation for about three decades, and significant progress has been made towards understanding of the physical processes associated with rapidly pitching aerofoils beyond the static stall angle of attack.