1
مکانیک::
نیروی برآی نوسانی
Figure 2.3: Mean drag coefficient (blue line), oscillatory drag coefficient (green dash line) and RMS of fluctuating lift coefficient (purple dash line) of a circular cylinder as a function of Re along with the status of its boundary layer and wake region at corresponding Re.
The variable pressure distribution leads to fluctuating lift and drag forces.
As the reduced velocity increases, the wake becomes unstable and the vortices start to shed alternatively and produce fluctuating lift and drag forces.
In one of the most influential studies on semi-empirical models, [66] showed that fluctuating lift force exerted to an elastically mounted circular cylinder by vortex-shedding can be modelled via a van der Pol equation as:
واژگان شبکه مترجمین ایران