Applied Mechanics and Materials Vols. 799-800

Abstract: In the paper the total FE model of the MAN gas holder is built to analysis oil leak problem of MAN gas holder in steel plant. By comparing the FE result and theoretical result of MAN gas holder under internal pressure, it is observed that they have high consistency, which proved the reliability of FE model, and provided valuable basis for the following calculation. The main body load of MAN gas holder is circumferential stress, which is observed in total structure analysis result of the MAN gas holder. This kind of stress distribution proved to be the main reason of oil leak.

Abstract: The structure of inertial-type counter flow screen is presented in this paper. It can be proved that the solid wastes with different friction factors and elasticity coefficients can be well separated by inertial-type counter flow screen. The more difference they have in friction factors and elasticity coefficients, the better sorting performance can be achieved. The selection and calculation on the dynamical parameters of inertial-type counter flow screen is carried out. The study provides the theory basis for the design on new-type friction separation equipment and develops new prospects for the application of inertial-type counter flow screen.

Abstract: This paper focuses on the comparison between underwater explosion (UNDEX) shock loading empirical formulations. First, the numerical simulations for a cylindrical pressure hull subjected to UNDEX loading were conducted and the results are close to the failure modes shown in experiments of Kwon (1993). Second, the empirical UNDEX loading formula of Cole (1948), Keil (1961) and Shin (1994) used in cylinder subjected to underwater shock loading were compared. The simulation results by using three empirical formulas were compared and Shin’s (or Cole’s) empirical formula was shown to be better than the other empirical formulations when subjected to an UNDEX under the same conditions. The analytical results offer a valuable reference to the research of underwater explosion.

Abstract: This paper investigates the effect of radial run-out on the transient responses of spur gear pairs with backlash. With the selection of contact parameters which are based on existing contact models, an ADAMS model for a set of spur gears is created and the results are compared with the available solutions in the literature. After observing that ADAMS solutions obtained by determined contact parameters are in close agreement with the solutions given in the literature; a gear which has radial run-out is replaced with the ideal gear. The results are shown to demonstrate the effect of radial run-out on the output gear.

Abstract: Because of growing global concern for the increasing energy demand and the resulting environmental impact of fossil fuel based energy sources, renewable and environmental friendly energy sources are critically sought. Wind turbines are generally conceived as the key renewable energy sources, but more innovative solutions should augment the classical design and control of wind turbines in order to improve the energy conversion efficiency. For areas outside the integrated grid system and harsh operation conditions in particular vertical axis wind turbines show promising results. This turbine design is previously considered less efficient, and thus the performance has not been sufficiently documented. This paper attempts to contribute in better understanding of the wind flow around the rotor, and the way the rotor components react to the resulting pressure. The turbine is first modeled in 3D CAD system and simulated in a flow simulator in a virtual wind tunnel. Then the iso-lines of velocity and pressure distribution are plotted at selected sections of the turbine plane and the profiles are studied to characterize the fluctuations of the dynamic pressure and identify the vulnerable zone of the turbine blades and the structure.

Abstract: Critical speed rotor phenomenon characteristics at gas turbine generator is evaluated using finite element method. In this study, the critical speed is evaluated based on the over speed of 4500 rpm. The critical speed of the rotor is investigated in the Campbell diagram, which shows the relationship between natural frequency and rotational velocity of the system Dynamic characteristic in this paper simulated with ANSYS rotor dynamic software. The Finite Element simulation results will be known forms of vibration at each critical speed. Finally the results od simulation can be a reference for dynamic analysis and optimized the design of rotor generator.

Abstract: The energy minimization multi-scale model is applied to the plane jet. The stability conditions of plane jets is adopted to predict the velocity distribution of plane jet. When the ratio of total dissipation to viscous dissipation tends to the maximum is used as the optimization condition and entrancement factor is considered as a constant, the Gauss velocity distribution can be concluded in the plane jet.

Abstract: The unit modular technique is one in which unit modules are prefabricated at a factory and then transported to a construction site for assembly. When the external wall, windows, etc. is damaged during the transportation, the efficiency of unit modular method is deteriorated. Taking this into account, in this study an adapter block used to fix the unit module to a truck was proposed to ensure no damage was caused to the external wall.The L-type adapter block proposed in this study was evaluated the structural safety through simulation method. The result of the simulation is that it seems desirable to set the working load of the L-type adapter block as 15kN for Case 1 and as 30kN for Case 2. Therefore, when the L-type adapter block is utilized under the conditions in which the same load is applied as in Case 2, it is expected that safety will be improved.

Abstract: The diffuser in wind tunnel plays a vital role to improve flow field quality. Many flow adjusting devices in diffuser were studied by lots of researchers in the world to inhibit flow separation. However, most of them were applied on closed-circuit wind tunnel with high speed. It is necessary to design appropriate flow adjusting device for diffuser in open-circuit wind tunnel with low speed which was increasingly used in aerodynamic experiment. The structure of a new open-circuit wind tunnel with low speed was firstly introduced in this paper. The flow adjusting device was designed, which was composed of three parts, namely contracting cone, air guide plate and screen. On the basis of analysis model for diffuser, the influences of contracting cone, air guide plate and screen on flow field quality were respectively given by CFX simulation that was using multiple reference frames and RNG k-ε turbulence model. Case study showed that the role of single part was limited, combined effect of three parts in flow adjusting device could greatly improve quality of flow field in diffuser. The study results mentioned above are useful for designing flow adjusting device in diffuser of practical open-circuit wind tunnel with low speed.

Abstract: Mechanical analysis of flexible pipe during installation is presented in this paper. The configuration, tension and bending moment of the flexible are important issues during the installation. A reasonable theoretical model is proposed to handle the pipe configuration and the loads during installation. Numerical iteration program for the model is developed to get the tension, bending moment distribution and the pipe configuration. Two segments which are suspended segment and seabed segment are analyzed with different calculation model for their different load conditions and boundary conditions. Finite element model is established by Abaqus to verify the results from the theoretical model. The results from theoretical are very close to the ones got from FEM. Typical installation method J-lay method is applied to perform the FEM and numerical analysis.