The effect of uniform flow appears as additional stiffness and damping, which are often called aerodynamic stiffness and aerodynamic damping. These effects are functions of flow (wind) speed.
The objective of this ambient monitoring was to extract aerodynamic stiffness and aerodynamic damping from the girder response data under various levels of wind speeds.
If the measurement is performed in windy condition, wind speed and direction is also measured for calculating the aerodynamic damping
that is used in calculation of effective damping for cables .
Though the shift from stall regulation to pitch control will significantly avoid stall related instability during operation, due to the inherent low aerodynamic damping
for edgewise model, the edgewise instability is still a critical problem.
less than zero is the necessary condition of instability to gallop; the formula for the criterion is as follows:
Inter-blade coupling (due to the shrouds, aerodynamic damping
and etc.) is considered.
Reduced aerodynamic damping
does not necessarily represent a flutter problem, because the inherent damping of sailplane structure was neglected at current stage of investigation and the aerodynamic models used in analyses were not validated.
In effect, if the aerodynamic force (proportional in this case to dz/df) is considered as a contribution to the total damping of the system (aerodynamic damping
), the total damping coefficient is
Some of the explanations are rather in-depth--spider webs not throwing insects back off after they hit the web because of hysteresis and aerodynamic damping
, for instance.
"With the model, we found, unexpectedly, that aerodynamic damping
has a tremendous effect on capturing prey On the scale of insects, air resistance plays a large role.
Hwang, "Effects of hysteretic and aerodynamic damping
on supersonic panel flutter of composite plates," Journal of Sound and Vibration, vol.
Based on the aerodynamic damping
estimated from the wind tunnel tests  at Tongji University, the modal damping ratio of SCB is finally obtained by deducting the corresponding aerodynamic damping
ratio from the identified total damping ratio.