A Method of Bending Shrinkage Groove on Vortex Suppression and Energy Improvement for a Hydrofoil with Tip Gap
PROCESSES
Authors: Hu, Zanao; Huang, Chuibing; Huang, Zhenwei; Zhang, Jinsong
Abstract
Hydro energy is a kind of typical renewable energy, which can be converted by hydraulic machinery. However, tip leakage vortex (TLV) has a significant negative influence on the flow pattern and energy performance of hydraulic machinery. In this paper, a bending shrinkage groove (BSG) is proposed to suppress the TLV and improve the energy performance of a hydrofoil first, and then a parametric optimization design method is briefly introduced and applied to determine the optimal configuration of the groove. The main geometric parameters of the groove are selected as optimized variables and three different groove configurations are selected from the optimization result. Finally, the performance improvement of the hydrofoil with groove, the sensitivity analysis of the optimization variables, and the groove impacts on the TLV and flow patterns are investigated. The results demonstrate that the preferred groove reduces the non-dimensional Q criterion vortex isosurfaces area (Q(area) = 2 x 10(7)) by 5.13% and increases the lift drag ratio by 17.02%, comparing to the origin hydrofoil. Groove depth d and groove width w are proved to have more significant impacts on the hydrofoil energy performance. The TLV and flow patterns are greatly affected by the different BSG configurations, and the wider BSG contributed to reducing the area of TLV, at the cost of energy performance deterioration.
Adsorption behaviors of Eu(III) on granite: batch, electron probe micro-analysis and modeling studies
ENVIRONMENTAL EARTH SCIENCES
Authors: Li, Hong; He, Bihong; Li, Ping; Fan, Qiaohui; Wu, Hanyu; Liang, Jianjun; Liu, Chunli; Yu, Tao
Abstract
Although granite has been widelyconsidered as the host rock of the high-level radioactive waste (HLRW) repository in the world, the adsorption behaviors of radionuclides on granite are quite complicated and still unclear, especially at molecular scales. In this study, the adsorption behaviors of europium(III) on Beishan granite (BSG), a preliminary selection of host rock for the HLRW repository in China, were explored under environmental conditions combining batch, electron probe micro-analyzer (EPMA), and modeling approaches. X-ray diffraction (XRD) pattern confirmed that albite, quartz and biotite were the main mineralogical components for the BSG grains. Eu(III) species on BSG grains are predominant as the ion exchange (X3Eu0) and the inner sphere complexes of (SOEu)-O-w(OH)(2)(0), (SOEu)-O-s(OH)(2),(0) (SOEu2+)-O-s, and (SOEu2+)-O-w. EPMA showed that the distribution of Eu(III) on BSG grains was strongly correlated to the biotite, which suggested that biotite is the host phase for retarding trivalent actinides in the BSG grains. The presence of soil humic and fulvic acids could enhance Eu(III) adsorption on BSG grains under low-pH conditions, and inhibit the adsorption under higher pH range.