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The structure of piezoceramic fiber composite actuator was designed, consisting of interdigitated electrode plates, binder and piezoceramic fiber composite layer. The flexible, planar piezoceramic fiber composite actuators were prepared by arrangement-casting method. The electrical and mechanical properties of the PZN-PZT ceramics were tested. Piezoelectric properties of piezoceramic fiber composite were estimated by iso-strain mixing formulas. The strain properties of the actuator were tested using dynamic response system based on LabVIEW. The piezoelectric constant d33, Curie temperature Tc and elastic compliance coefficient s33 of the PZN-PZT ceramics are found to be 520 pC/N, 320¡䟡nd 20.5×10^–12 m²/N, respectively. Theory of piezoelectric constants and of piezoceramic fiber composite are 509 and –156 pC/N, respectively. Test results show that the actuator is capable of producing large, directional in-plane strains. 100 parts-per-million longitudinal strain and 58 parts-per-million transverse strain were generated under a 300 V peak-to-peak applied voltage cycle. The stretching of the longitudinal and transverse directions are 3.6 μm and 1.7 μm, respectively, indicating the actuator has a high electromechanical property

Owing to its effective energy dissipation and aeration, a stepped spillway is commonly used for flood release in hydraulic projects. Its conventional design features horizontal step surfaces. Designed for certain flow rates, it does not function satisfactorily at larger discharges. To improve this, layouts with inclined step surfaces, both downward and upward, are proposed. Computational fluid dynamics (CFD) modelling in 3D is performed to examine and compare their flow properties in the skimming flow. The results suggest that a shift from a downward to an upward layout leads to a gradual decrease in the flow velocity at the chute end; the latter exhibit higher energy dissipation efficiency. Moreover, equations are developed to estimate the velocity and energy loss. The flow velocity in the developing zone, described by a power law, shows a decline with an increase in the angle of inclination. The downward layout is subjected to somewhat higher risk of cavitation if implemented in a prototype. The extreme pressure loads acting upon an upward layout are larger, and a correlation is proposed for its prediction. On an inclined surface, either upward or downward, the pressure demonstrates an S-shaped distribution. On a vertical surface, the flow pressure increases, after an initial decline over a short distance, towards the chute bottom.

In order to meet the weight reduction requirement of a tactical component, feasibility analysis by selected raw material, analyzing the stress and displacement under the working condition by finite element analysis method, a design of molding and curing are proposed. The results of feasibility by choosing suitable show that the mass of the composite component is reduced from 8.3Kg to 2.9Kg after optimization with the theoretical weight loss is 60%; the maximum stress is 50.9 MPa and the maximum displacement is 0.089mm; which meet the design requirement. The internal expansion pressure of the mold is designed as 1.0 MPa which meets the molding requirement. The design of this lightweight tactical composite component is clear, reasonable and feasible, which will have a certain guiding significance for the research of molding technology in related field.

Abstract. The main structure and the production theory of scraped surface heat exchanger was introduced. The heat transfer mechanism of heat exchanger is analyzed, and the mathematical model of heat transfer is established in this paper. There had three mode of heat transfer in Scraped surface heat exchanger. They were External heat transfer, Internal heat transfer ,Convection heat transfer, respectively, the mathematical model corresponding to them were established. On this basis, production equipment line with scraper heat exchanger as the core machine was improved.