Advanced Materials Research Vols. 317-319

Abstract: The self-excited oscillation pulsed water jet (SEOP Jet ) has been used extensively in oil and gas well drilling, mineral mining, cutting and industrial cleaning. In order to improve the valid stand-off distance of water jet pressure and its range of action, the model of oscillation frequency of jet was given on the basis of hydroacoustics and fluid dynamics for better understanding the principle of increasing jet pressure amplitude. The SD150test system was used to analyze the effects of dynamic parameters on the frequency, the effects of pump pressure and the cavity length on the frequency were studied in detail. The test results showed that the peak value of the SEOP Jet is larger by about 20% than that of continuous jet. The oscillation frequency increased while increasing pump pressure and decreased while increasing cavity length. There was an optimum cavity length corresponding to the pressure peak value of the SEOP Jet. Experimental result is in good agreement with that of theoretical analysis.

Abstract: The mixing effect in steel converter process is very important to the fluid flow and mass transfer in bath and directly affects the chemical reaction and temperature homogeneity in the industry steel process. The cold model was employed to research the relationship of mixing time, agitation power, lance type, operation parameters, bath shape et al. According to the results, the mixing time of the bath decreases with larger gas flow rate and bigger diameter of the bath. Increasing the nozzle inclination properly is benefit for decreasing the mixing time and improving the agitation of the bath. The relationship of mixing time and lance height is complicated, because the mixing time is fluctuant by the lance rising. By introduce the relative energy utilization factor, the agitation power utilization was analyzed and compared under different conditions. The energy efficiency is higher with larger nozzle inclination as well as the bigger ratio of diameter and depth of the bath.

Abstract: A novel check valve - passive control shuttle-type check valve is introduced in this paper based on the comparison of the existing swing check valves including the liquid, structural principle, flow resistance coefficient, airproof and start-stop performances. The experimental and simulation analysis validated that shuttle-type check valve has the advantages of symmetric structure along the pipeline axis, balance circle flow, low coefficient streamline, adjustable start-stop time, multi-airproof, zero leakage and less noise.

Abstract: Multi-circuit gear pump working performance cannot be affected by load, and it outputs the same amount of oil in every port, which can provide static pressure supporting for the guide ways of machine tool. The test schematic is designed with the destination of testing multi-circuit gear pump hydraulic performance. Test equipment and hydraulic oil are selected scientifically and reasonably based on multi-circuit gear pump performance parameters which have been designed, and then hydraulic system is installed in order to execute performance testing.

Abstract: The operating principle of cartridge valve controlled by high-speed on/off valve is expounded, the mathematical models are established on the basis of the principle. The simulation model of system is created in AMEsim. By analyzing the curve charts of spool’s displacement and outlet flow rate of cartridge valve, the PWM signal frequency and duty cycle have influences on the control performance of cartridge valve controlled by high-speed on/off valve are concluded. The results show that the cartridge valve can be got good linear control when the input signal is low- frequency and moderate duty cycle.

Abstract: The automotive power steering units must be taken performance test after they are integrated assembly and then left the factory if it is qualified.Because its internal flow channel is very complicated and the residual hydraulic oil can not be eleminated clearly.So we can set up a 3D model flow channel based on CATIA and use FLUENT software to analysis the key flow channel ,analysing it's pressure distribution and velocity vector diagram then get the real reasonable resluts ,which can provide the basic for the ejector designing

Abstract: The parameters uncertainty and external disturbance play a negative role to improve electro-hydraulic position servo system performance. The valve controlled cylinder system model is established, using the traditional PID control strategy and reaching law control strategy for simulating the system, respectively, the two methods have similar control effects in the ideal model, but considering the external disturbances, the index approaches sliding mode control law has better response speed and stability. Research shown that sliding mode control algorithm has an important role for improving the performance of hydraulic servo position control system.

Abstract: Taking electrohydraulic servo control system used in mould oscillation in bloom continuous casting machine as the object of research, AMESim software is used to establish the model of the electrohydraulic servo control system ,also simulate and analysis the system,which theoretically confirms the reliability of the electrohydraulic servo control system.The software is also used for dynamic analysis about the control system.

Abstract: For the complex features of many varieties, varying quantities of inserting production, we use such a complex system as Swarm intelligence to study the process of the production line of SMEs setting up and human resources scheduling. Based on the analysis of the operating characteristics of production cell and their comparison labor division model of the ant colony, it re-designs the workers’ features and the deployment of staff between the Production cells and finally, realizes an adaptive division of labor model by the control of computer, depending on the production task requirements and each production cell load. The experiments show that the digital simulation results can match the real cases well.

Abstract: A new control algorithm combing Reduced-order observer, LQG and Fuzzy Logic Controller (RLFLC) is proposed to compromise the classical suspension conflict between riding comfort and driving safety. The RLFLC optimizes the weights of the performance indexes on line in accordance with variational suspension deflection and body acceleration to schedule the gain of LQG controller dynamically for achieving multiple control objectives. In particular, a reduced-order observer is introduced to estimate some state variables which are difficult to measure. Compared with the passive suspension and the conventional LQG control system, the simulation results show that RLFLC can be adaptive to vehicle speed and road conditions to improve not only the riding comfort at low speeds, but also driving safety at high speeds without violating the given suspension deflection limit