Wind tunnel tests on the rigid model of large-span shallow spherical shell roof structure were carried out. The variation rule and the calculation method for the average shape coefficient of the fluctuating wind pressure under six different typical wind directions were obtained. The wind pressure distribution of the node deflection and cross section stress was numerically investigated and analyzed. Meanwhile, the effect of mechanics-flow form of the typical spherical shell structure on the wind pressure distribution was analyzed quantitatively. In this study, it is found that the results of numerical simulation agree well with the wind tunnel test data. The study on the mechanical characteristics, as well as the wind vibration research, of the spherical shell structure in different working conditions provides a reliable theoretical basis for the mechanical index of the wind vibration.
Transonic buffet not only influences the structural integrity, handling quality and ride comfort, but also limits the flight envelope of transporters and airliners. To delay buffet onset and alleviate the buffet load, the effects of both steady and periodic tangential slot blowing are investigated. The results show that steady tangential blowing on the airfoil upper surface can postpone the buffet onset margin and evidently increase the lift coefficient at incidence angles near and above the buffet onset case of the clean airfoil. Under buffeting conditions of the clean airfoil, unsteady aerodynamic loads can be greatly suppressed by both steady and periodic blowing. The control effort is depicted as reduced wedge effect and weakened dynamic effect. The buffet mechanism includes (a) the feedback loop between the Kutta wave and the separation bubble under the shock foot, and (b) the interaction between the shear layer shed by the shockwave and Kutta waves. Under blowing conditions, the upstream creeping Kutta waves are prevented, and the intensity of the shear layer shed by the shockwave into separated flows is evidently reduced. Parametric studies show that the control effect is reduced as the blowing slot moves downstream, and steady blowing at 41% x/c is the most favorable control case.
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