In a water hydraulic jet pipe servo valve, the overall performance of the valve is directly influenced by the structure dimension of the receiver and the prestage— jet pipe amplifier. This paper deals with the influence rules of the structure dimension parameters and performance parameters on the buildup pressure in the two receiving holes, including the vertical clearance between the nozzle and the receiver, the diameter of the nozzle hole, the diameter of the receiving orifice, and the nozzle offset distance. The best combination of structure size is finally obtained by using numerical simulation, computer emulation and experiment analysis methods. Then build up the finite volume analysis models about the pressure field and the speed field of the jet pipe amplifier. Through analyzing the characteristics of the flow field, a mathematics relation between the jet nozzle offset and the pressure ratio inside the two receiver holes is established, which reveals the energy distribution and conversion mechanism. The conclusion could be an important reference for the design and research of jet pipe servo valve.

According to the subjectivity, randomness and fatigue of the satisfaction selection of online teaching evaluation indicators for the students, the level of teachers teaching can not truly measure by the evaluation results. This paper introduces the fuzzy comprehensive evaluation method to deal with the evaluation data, and Practice has proved that this method produced results more equitable to reflect on teaching level. Which help teachers to promptly improve and improve teaching, the variable quality of teaching time control for process control, change the static management for dynamic management.

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The main components of the opposed biconinal cone screw high-pressure seawater hydraulic pump is the rubber bush and metal cone screw, and the interaction of the bush and cone screw is one of the main factors affecting the novel pump performance. The deformation and stress of the bush and cone screw under the initial interference is analyzed by the nonlinear finite element analysis. The analysis shows that: under the effect of the initial interference, large displacement is present to the radial surface of the cone screw, and the displacement of the radial surface mainly affects the displacement vector sum of the cone screw, and the deformation decreases gradually from the middle to the ends of the cone screw, while the cone screw is bending; the deformation in three direction of the bush is close to each other, but the location of the maximum displacement in each direction is different; with the shrink range increasing, the deformation of the cone screw and bush increases, but the deformation of the cone screw is much smaller than that of bush, so the deformation of the bush mainly affects the seal between the cone screw and bush, and the shrink range between the cone screw and bush decreases because of the deformation of the bush. Over the role of the interference force, the maximum von mises stress of the cone screw is an order larger than that of bush, and the maximum von mises stress both increases with the shrink range increasing; although shrink range is different, the location of the maximum von mises about the cone screw and bush is the same.