Applied Mechanics and Materials Vols. 397-400

Abstract: The characteristics of traditional load sensitive system and the control system of electric hydraulic flow matching are introduced comparatively. In order to improve the energy saving and the overall control performance of wheel loader, Electro-hydraulic flow matching control system is adopted. In the meantime, the machine-liquid walking institution in the traditional sense is changed into full hydraulic pressure drive institution by using the module modeling way, which omits the "double" system including the hydraulic torque converter and the transmission constitute, simplifies the chassis structure and improves the flexibility of the machine. Simulation model of the wheel loader of full hydraulic pressure drive is established by the software named AMEsim, which provides reference for the designs and applications of the matching control system of electric hydraulic flow applied to the full hydraulic pressure drive wheel loader.

Abstract: Laval nozzle is the commonly used device in rocket engine and aero engine. this paper, the numerical model is derived. The convergent section subsonic flow and divergent section hypersonic flow are simulated in dimensionless method. Reverting the dimension, the result can be seen that the analytical solution, the CFX simulation solution and the numerical are in uniform.

Abstract: Blast wave is numerical simulated based on FCT method. According to the comparative analysis, taking Henrych empirical formula as a standard, FCT method is more accuracy than Godunov method. Moreover, it has been found that the numerical accuracy is insufficient when the distance is small, it is necessary to develop and modify the numerical method continuously.

Abstract: The high parameter pressure reducing valve (PRV) is a key device for regulating gas pressure in industrial processes. For the large flow and the instability of the high pressure and high temperature steam, the noise of the working PRV is large and also its energy consumption. A numerical analysis of the flow field and acoustic field of the inner high parameter PRV was conducted, the main cause of the aerodynamic noise was analyzed. Basing on the RNG k-ε Model and the Broadband Noise Source Model, the flow and acoustic power are calculated. Comparing the distribution of acoustic power level with the distribution of the velocity and turbulent intensity, it is shown that the main reasons for noise in the PRV are forming and shedding alternately vortexes and shock waves of jet flow.

Abstract: The present SO₂ gas detection technology and research were studied. The paper aimed at the problems of low SO₂ concentration, much interference with gases, long response time in the flue gas desulphurization process. The improvements were made based on non-dispersive infrared detection. Gas filter correlation technology was adopted to filter out the interference of other gases. In the hardware, thermoelectric release detector was used to detect the signal to shorten the response time. All these efforts are made to meet the requirement of realtime and on line control in the desulphurization system.

Abstract: Wave gliders as innovative autonomous ocean-going vehicles harvest the abundant marine natural energy for persistent ocean environment monitoring. This paper analyzes wave glider’s operating mechanism and builds the dynamic model of wave glider. By simplifying the model into 3 DOS in longitudinal plane and selecting three generalized velocity, the kinematic equations and the generalized force can be confirmed. Then, based on the equation of Kane vector operation modeling method, the explicit kinetic model of wave glider is presented. According to simulation study of the kinetic model, the relationship between the motion state of wave glider and the wave motion are indicated. The study provides theoretical guidance and reference for wave glider design.

Abstract: A prediction program for analysis of helicopter rotor rotation noise was developed based on Farassat1A formulation. The acoustic prediction program was validated by the comparison with the WOPWOP program results in the literature.The loads input for the acoustic calculation are obtained from CFD calculation. The directional characteristic analysis was conducted by this program. Some calculations were conducted for evaluating the influence of rotor parameters including rotor speed , blade pitch ,and blade dihedral for the helicopter rotor rotation noise in hover. The results show that some proper changes of rotor parameters can bring benefit in thickness and loading noise of helicopter rotor. Several conductive conclusions were summarized for the helicopter rotor noise reduction.

Abstract: The quasi-zero-stiffness vibration isolation system has witnessed significant development due to the pressing demands for low frequency and ultra-low frequency vibration isolation. In this study, the isolation theory and the characteristic of the quasi-zero-stiffness vibration isolation system are illustrated. Based on its implementation mechanics, a comprehensive assessment of recent advances of the quasi-zero-stiffness vibration isolation system is presented. The future research directions are finally prospected.

Abstract: As a major force-bearing structure of Active Phased Array Radar, the Active Fixing-boards vibration characteristics should be investigated in the engineering design stage and the prototype stage. In this paper, Finite Element Method (FEM) is used for modal simulation and the detailed modal experiment is used to analyze the modal parameters of the first 6 modes. The results show that the modal parameters calculated by FEM agree well with those by modal experiment.

Abstract: Vertical planetary mill is a kind of efficient grinding equipment. Due to its unique design, the materials can suffer combined effects of squeezing, shearing and grinding. this paper developed the virtual prototype of vertical planetary grinding wheel sand reclamation equipment based on virtual prototyping technology, and did the dynamic simulation with this virtual prototype. It will use ADAMS to do the dynamic simulation, and it can provide reference price for staff.