Advanced Materials Research Vols. 614-615

Abstract: The flow field of inner stack of one coal-fired power plant in Shanghai was simulated. The results showed that there was a larger turbulent region at the upper parts of the entrance in the stack. The inner wall at the opposite of the entrance withstands a much greater shock, and this region is badly worn. The speed in the central and upper region is more stable. The stack is basically running in a vacuum state, which contributes to corrosion mitigation. The temperature shows a decrease trend with the increase of height in the range of 10°C. The temperature of the center part is slightly higher than the ambient part. And with the increase of the stack height, the radial temperature gradient increases.

Abstract: In order to research the law of chamber shape’s influencing on Axial Force in Hydrodynamic Coupling, flow field and axial force are numeric simulated at different chamber shapes in full filling rate by using separation solver, realizable k~ε model and PISO algorithm with CFD. The result shows that chamber shape has a greater impact on the axial force, and the influence weaks with the increase of speed ratio.

Abstract: In practice, it is basically difficult even with controlled measurement environment to acquire a steady, uniform and fully developed flow. The flow entering diffuser was severely distorted despite a sufficient hydrodynamic entrance length already introduced. This was mainly due to the imperfect joining of duct and the abrupt change of the inlet cross-section applied. In this study, several basic features of a low subsonic wind tunnel, i.e. a centrifugal blower with 3-phase inverter, a settling chamber, screens and a contraction cone, are designed and developed for a turning diffuser application in order to improve the flow quality. The flow profiles are examined using Pitot static probe at five measurement points within the range of inflow Reynolds number, Rein= 5.786E+04-1.775E+05. The steady, uniform and fully developed turbulent flow profiles with an average deviation with theory of about 3.5% are obtained. This proves that a good flow quality could be produced by means of incorporating some basic features of a low subsonic wind tunnel to the system.

Abstract: The technology of film cooling is one of the most effective means of protecting the turbine blades. In this paper, flow structures of the turbine stator blade with six hole-rows at different blowing ratio（M=0.5, 1.0 and 1.5）and setting angles（β=40°, 50°, 60°, 70°, 80° and 90°） was measured by PIV in piston flow type of low-speed wind tunnel laboratory. Velocity was analyzed. Results show that: velocity gradient of suction side was much higher than pressure side and increased with setting angle reduction; Adherence of film is influenced by setting angle and blowing ratio, when M=1.0 and β=70° anchorage dependent is best and suction side is greater than pressure side.

Abstract: Gas-solid flow behavior of the bottom zone of a 65t/h High-low bed CFB was simulated using the commercial computational fluid dynamics (CFD) software package Fluent. The Eulerian-Eulerian model (EEM) based on the kinetic theory of granular flow (KTGF) was adopted. This approach treated each phase as continuous separately. The link between the gas and solid phases was through drag model and turbulence model. While the turbulence was simulated by the standard k-ε and mixture multiphase model, the Gidaspow drag model was used to model the interphase interaction. Four phases were set to achieve size distribution in the EEM. Gas and solid flow profiles are obtained for solid velocity, solid volume fraction, pressure, and size distribution. The results show that EEM can predict preferably the internal circulation process of the dense zone high-low bed CFB.

Abstract: The imbalance caused by eccentric sleeve radial compliance mechanism rotor system is a main issue in scroll compressor. In this study, the mechanical model of the structure with the eccentric sleeve behind the orbiting scroll is established, the offset level of the main and second balance weight inertia force action line and inertia force action line of the eccentric weight, as well as the effect of this deviation on the second balance and the main and second bearing loads were investigated in terms of working principle, structure and loading. The results show that the structure has great influence on scroll compressor rotor system balance in reducing orbiting radius regulation. It is suggested that the correlated parameters should be optimized in designing radial compliance mechanism structure.

Abstract: A 3D numerical model was performed to simulate the different cases of the water flow across different-shaped square cylinders. Figures of streamlines and turbulent kinetic energy contour lines in different cases were obtained. Through the comparison of streamlines, the areas of strong turbulent kinetic energy and the strongest turbulent kinetic energy nucleus, the results indicated that,(i) two symmetrical vortexes were formed behind the regular quadrilateral square cylinder and the “⊥”-shaped square cylinder ,respectively, and the former were bigger than the latter .While the flow crossed the “±”-shaped square cylinder without forming vortex.(ii) When water flowed around different-shaped square cylinders, from the regular quadrilateral one, the “⊥”-shaped one to the “±”-shaped one, successively, the strong turbulent kinetic energy distribution area, in which turbulence kinetic energy value was above 18,gradually increased; while the strongest turbulence kinetic energy nucleus, whose value of turbulence kinetic energy was the largest among turbulence kinetic energy nucleuses in the strong turbulent kinetic energy distribution area, moved forward gradually and its area was smaller and smaller.

Abstract: The design idea of monitored control subsystem of vessel dynamic cyclone oily water separator is based on LabVIEW software platform, adopted DataSocket technology, by using DAQcard-A-16E-4E data acquisition card to realize real-time monitoring. This paper introduced the components of the monitored control system, analyzed its working conditions. According to the experimental operating records on some real ships, the application results and characteristics are summarized.

Abstract: Engineering practices showed side-walls in free-flow discharge tunnels with high speed flows and low pressure tended to be damaged by cavitation, especially behind concave reach. In this paper through experiment an aerator with side-walls sudden enlargement and soleplate vertical dropping was introduced on the concave reach bottom of the Vertical-Bend free-flow spillway tunnel side-walls. By applying this type of aerator, air entrainment increases significantly and un-airflow areas disappear. Experimental observations show that lateral cavity and bottom cavity are linked to each other and the forced aeration forms behind the aerator, which protects sidewalls and soleplates against cavitation damage.

Abstract: By the potential theory, axisymmetric flow problem is converted into boundary integral equations (BIEs). The mechanical quadrature methods (MQMs) are presented to deal with the singularities in the integral kernels, which are simple without any singularity integral computation. In addition, the convergence rate of the MQMs can be improved by using the extrapolation methods (EMs). The efficiency of the algorithms is illustrated by examples.