2
مکانیک::
جریان عرضی
Due to combined lift/drag forces associated with the shedding vortices and the fact that actual underwater structures possess multiple natural frequencies in different directions, a condition of coupled cross-flow/in-line VIV is certainly achievable in most practical situations.
* In Chapter 5, analytical closed-form expressions are derived for the extraction of hydrodynamic coefficients and maximum responses from the 2DOF VIV, the system phase relationships of wake and cylinder motions and various maps of hydrodynamic coefficients are presented, the analytically-obtained contour plots of maximum cross-flow/in-line responses are highlighted and a shortcoming of using a linear structural oscillator and applying a constant empirical coefficient to the wake oscillator is underlined.
Figures 2.4 (a) and (b) show the circular cylinders which are subjected to a fluid flow, elastically mounted and free to vibrate in the streamwise and cross-flow (CF) directions, respectively.
Due to combined lift/drag forces associated with the shedding vortices and the fact that actual underwater structures possess multiple natural frequencies in different directions, a condition of coupled cross-flow/in-line VIV is certainly achievable in most practical situations which can be responsible for the dangerously-amplified dynamics.
In addition, a large third harmonic component of the lift force was observed although the main cross-flow response was primarily associated with the first-harmonic lift force.
واژگان شبکه مترجمین ایران