3results about How to "Reduce aerodynamic force" patented technology

The invention provides a tower bottom limit load reduction method based on blade pre-variable pitch automatic optimization. The method comprises the steps that an initial variable pitch power interval and an initial pre-variable pitch angle are set; calculating a plurality of tower bottom combined bending moment loads under different wind speeds under the working condition of DLC1.3, and respectively drawing a power-load scatter diagram and a power-load envelope curve diagram according to the maximum load value of the tower bottom combined bending moment and the power of the wind turbine generator when the load value appears; after the pre-variable pitch angle is adjusted, the multiple tower bottom combined bending moment loads under the DLC1.3 working condition and different wind speeds are calculated again, and the maximum value in the multiple tower bottom combined bending moment loads is taken as the maximum tower bottom combined bending moment load value; the maximum load value of the tower bottom combined bending moment is compared with the target load of the tower bottom combined bending moment, and if the maximum load value is smaller than the target load value, calculation of tower bottom limit load reduction is completed. The blade pitch angle can be controlled to change along with the change of power, so that the aerodynamic force borne by the wind wheel is reduced, the tower bottom load is reduced, and the purpose of reducing the tower bottom limit load is achieved.

The utility model discloses a booster stage of a carrier rocket, which belongs to the technical field of carrier rocket structures and comprises an inclined nose cone, an engine, a tail section and a binding connection mechanism. The engine is arranged between the inclined head cone and the tail section; the upper end of the engine is fixedly connected with the tail end of the inclined head cone; the lower end of the engine is fixedly connected with the tail section; the binding connecting mechanism comprises a main binding part and a binding connecting rod; the main binding and the binding connecting rod are located on the same radial plane penetrating through the axis of the engine. The main binding part is fixedly connected with the inclined head cone; and the binding connecting rod is fixedly connected with the engine. The aerodynamic force can be reduced, the bearing force transmission mode is simple, the structural scheme is reliable, and the machining cost is low.

The invention discloses a vertical shaft impeller with a horizontal inhaul cable and a wind turbine generator. The device comprises an impeller and an inhaul cable assembly. The impeller comprises straight blades, an impeller support and an impeller rotating shaft. The straight blades are tail-swinging type variable wing type blades. The inhaul cable assembly comprises an inhaul cable ring, an inhaul cable supporting piece, an inhaul cable fixing piece and a speed limiting tension spring. Each group of inhaul cable rings is of a closed polygonal structure formed by connecting an inhaul cable and at least one speed limiting tension spring. And each group of inhaul cable rings is arranged on the wing surface, close to the impeller rotating shaft, of the movable wing-shaped part through an inhaul cable fixing piece and an inhaul cable supporting piece. The inhaul cable fixing piece is connected with the inhaul cable supporting piece. Each group of inhaul cable rings is supported by a plurality of inhaul cable supporting pieces and can move relative to the inhaul cable supporting pieces. The inhaul cable rings balance the centrifugal force of the blades mutually, and a proper attack angle is guaranteed. The inhaul cable ring moves relative to the blades and adapts to the change of the distance between the blades, and the speed limiting tension spring can enable the blades to continuously swing outwards under the driving of centrifugal force, so that the aerodynamic force of the blades is greatly reduced, and overspeed braking is completed.