Applied Mechanics and Materials Vol. 779

Abstract: The dissolution mechanism of air and formation mechanism of bubble in the scopic-scale Be based on VOF model,with the help of Fluent software,For the single bubble rising in the water by numerical simulation;The results show that liquid phase flow state is a key factor affecting the speed of the bubbles rise;Pressure difference is the main reason cause the jets and bubbles deformation.

Abstract: Dust-removing blower is a key equipment in sintering plants, which can provide enough wind and negative pressure. It can also improve the efficiency of dust-removing. The vibration level of a dust-removing blower in a sintering plant is very high, which is beyond its normal value. Due to the complex working condition and strong background noise, it is difficult to extract fault features from the vibration signal of the dust-removing blower. Therefore, fault analysis of the blower is very difficult. Since the modulation phenomenon existed in the vibration signal of the blower is found, the envelope analysis based on the Hilbert transform is proposed to demodulate the vibration signal. The frequency spectrum of the demodulated signal shows that the first order frequency characteristic is obvious, which can effectively reveal the dynamic unbalance of the rotor system is the main reason of the abnormal vibration of the blower. According to this diagnosis, some possible reasons for the unbalance are proposed, as well as advices regarding to the repair of the blower system. Moreover, the test and analysis are conducted on the repaired blower system. The results show that the unbalance problem is eliminated and the blower can work normally, which can validate the accuracy and reliability of the proposed diagnosis method for fault analysis of the dust-removing blower.Keywords: dynamic unbalance; modulation; dust-removing blower; Hilbert Transform

Abstract: Copper stripping machine is an alternative to traditional artificial device. It is one of the key parts of the stripping device. It realizes stripping the sponge copper from the surface of the sheet nickel and ensures the subsequent automation. This article has carried on the simulation by using ADAMS to the movement of device, and base on theory of fluid mechanics and calculates the vibratory force on sheet nickel. By analysis, under the current hoisting height, the device can effectively guarantee shaking off the sponge copper on the surface of the sheet nickel. The electrolyte flushing of sponge copper removal effect is not obvious.

Abstract: The research object is horizontal stirred mill, and I have studied six different Stirrer disc (including the trapezoidal tooth disc, the serrated toothed disc, the common disc, decagonal disc, the octagonal disc and the hexagonal disc) structure on the horizontal stirred mill grinding efficiency. The paper applied EDEM for six different forms of Stirrer disc simulation, analyzing the simulation results, it is concluded that: when the Stirrer disc structure is the trapezoidal tooth disc, the comprehensive performance of horizontal stirred grinding machine is best, with high grinding efficiency, low power consumption, provide a reference for the design of the Horizontal stirred mill.

Abstract: In this paper, a distributed monitoring and intelligent diagnosis system is designed for large-scale electro-hydraulic devices, based on the utilization of information fusion technology. As a result of using multi-sensor data level, feature level and decision-making level information fusion methods, both precision and real-time performance of condition monitoring and fault diagnosis have been greatly improved, which leads to an advance in the accuracy of monitoring and diagnosis.

Abstract: Hydraulic generation system on helicopter generally consists of flight control hydraulic actuating circuit, landing gear retraction/extension hydraulic circuit, and wheel brake circuit. This paper studies on a volumetric speed control system applied in helicopter flight control actuating system. The system performance curve, deduced from the modeling, simulation and testing of the tail-actuating system, reveals that this volumetric speed control system meets the requirements of helicopter control system actuating.

Abstract: This paper introduces a new concept about pressure coupling in dual hydraulic motor synchronizing driving system. The mathematic models of systems are established in together-drive mode where two hydraulic motors together drive one common load and peer-to-peer mode where two motors drive one load respectively. Based on these mathematic models, a simulation analysis is conducted to probe the influence exerted by pressure coupling on the frequency response and the model consistency of two hydraulic motors, which gets verified by simulations and experiments later. The results show that pressure coupling reconstructing mathematic models of systems improves the model consistency of two motors and ameliorates synchronization performances.

Abstract: Hydraulic system is one of the most important parts of helicopter. Its function is to supply hydraulic power to the utilities. This paper studies an integration hydraulic system applied in helicopter flight control actuating system and simulates the system. The system has a small volume, light mass, meeting the requirements of helicopter control system actuating.

Abstract: The poor scavenging process of the hydraulic free piston engine which uses two-stroke engine as its driver was presented. A two-cylinder, four-stroke diesel engine was proposed to drive the single-piston hydraulic free piston engine to improve the scavenging process. The intake and release valves mechanism and fuel injection system were redesigned to adapt the performance of the single-piston hydraulic free piston engine. Feasibility and reliability of this new structure are verified through simulation.

Abstract: In the working process of hydraulic system, it is usually hard to match the operating parameters with the real-time load to get the optimized efficiency. This paper proposes an operating parameters matching and efficiency optimization method for hydraulic system based on data envelopment analysis(DEA). This method can provide the optimal input parameter scheme corresponding to the real-time load of system. Simulation experiments are carried out by AMESim. Results show that this method can improve the system efficiency by adjusting the input parameters to better match the output parameters on the premise of without changing the normal function of system. The study provides a theoretical basis for applying this method into practical engineering of hydraulic system efficiency optimization.