2results about How to "Reduce thrust fluctuation" patented technology

The application discloses a variable cycle engine double-loop closed-loop mode switching control method, which comprises the following steps: determining the tail nozzle network model parameters according to the dynamic thermodynamic mechanism analysis of a tail nozzle component, constructing a tail nozzle data-driven network model based on a BP neural network, and combining a component-level dynamic model of a main component in an upstream flow path to obtain a hybrid dynamic model of the variable cycle engine; according to the influence of an adjustable geometry component on performance parameters of the variable cycle engine, designing a double-loop closed-loop control scheme with variable speed and thrust feedback by taking thrust performance as an optimization target, and designing a mode switching control method of the model based on the hybrid dynamic model of the variable cycle engine. The tail nozzle model with a long time consumption in the variable cycle engine is simplified to reduce the time consumption of the whole machine dynamic model calculation, the double-loop closed-loop control scheme with variable speed and thrust and containing the mode switching process is proposed based on the model, and the stability of the variable cycle engine during mode switching can be effectively improved.

The application discloses a high thrust density cylindrical linear motor based on a wave-shaped air gap, which is composed of a wave-shaped stator core, an armature winding, a wave-shaped permanent magnet and a mover core, a wave-shaped air gap is arranged between the stator and the mover in the circumferential direction, the air gap area is increased, the air gap magnetic flux density distribution is adjusted, and the output thrust quality is improved. A wave-shaped permanent magnet excitation structure is arranged on the mover, the stator tooth top is arranged in a wave-shaped distribution same as the permanent magnet excitation structure distribution in the circumferential direction, and the air gap length is ensured to be equal everywhere. The wave-shaped permanent magnet excitation structure is composed of a plurality of pairs of permanent magnets arranged in a wave-shaped distribution in the circumferential direction and stacked in the axial direction, can generate a magnetic aggregation effect, and improve the excitation capacity in the motor. The cylindrical linear motor disclosed by the application has the characteristics of large output thrust, high thrust density and high efficiency, and is suitable for application occasions such as numerical control machine tool machining, electromagnetic launching and automobile suspension systems which require high thrust and high efficiency.