导叶可调式液力变矩器的内流场数值分析

研究LB46型导叶可调式液力变矩器和风力机传动系统的匹配特性问题,为实现风电机组的高效传动,需对变矩器流场的稳定性和可靠性进行研究。根据运行工况设定边界条件,采用Fluent软件SST K-ω计算模型和MRF(multiple refer-ence frame)技术,对不同导叶开度的LB46型变矩器进行全流道数值仿真,并与实验数据对比分析。结果表明,仿真数据与实验结果较为吻合,证明提出的方法能够用来分析变矩器的流场运行状况,为变矩器的后续优化设计提供支持。

Multiscale Simulation Starting at the Molecular Level for Adsorption Process Development

This article presents a multiscale simulation approach starting at the molecular level for the adsorption process development. A grand canonical Monte Carlo method is used for the prediction of adsorption isotherms of methanol on an activated carbon at the molecular level. The adsorption isotherms obtained in the linear region （or adsorption constant） are exploited as a model parameter required for the adsorption process simulation. The adsorption process model described by a set of partial differential equations （PDEs） is solved by using the conservation element and solution element method, which produces a fast and an accurate numerical solution to PDEs. The simulation results obtained from the adsorption constant estimated at the molecular level are in good agreement with the experimental results of the pulse response. The systematical multiscale simulation approach addressed in this study may be useful to accelerate the adsorption process development by reducing the number of experiments.

Role of matrix structure and flaw size distribution modification on deflection hardening behavior of polyvinyl alcohol fiber reinforced engineered cementitious composites(PVA-ECC)

The multiple cracking and deflection hardening performance of polyvinyl alcohol fiber reinforced engineered cementitious composites(PVA-ECC)under four-point flexural loading have been investigated.Matrices with different binder combinations and W/B ratios(from 0.44 to 0.78)providing satisfactory PVA fiber dispersion were specially designed.Effect of pre-existing flaw size distribution modification on deflection hardening behavior was comparatively studied by adding 3 mm diameter polyethylene beads into the mixtures(6%by total volume).Natural flaw size distributions of composites without beads were determined by cross sectional analysis.The crack number and crack width distributions of specimens after flexural loading were characterized and the possible causes of changes in multiple cracking and deflection hardening behavior by flaw size distribution modification were discussed.Promising results from the view point of deflection hardening behavior were obtained from metakaolin incorporated and flaw size distribution modified PVA-ECCs prepared with W/B=0.53.The dual roles of W/B ratio and superplasticizer content on flaw size distribution,cracking potential and fiber-matrix bond behavior were evaluated.Flaw size distribution modification is found beneficial in terms of ductility improvement at an optimized W/B ratio.

The Indexation and Monitoring of the Modern Transborder Processes

In the paper are analysed the phenomenon oftransborder processes, are identified the main levels of its vertical structure. In order to adequately reflect the objective reality of modern transfrontier processes, the author distinguishes within the multi-layered concept of ＇transfrontier＇ three levels as far as spatial dimensions are concerned： macro, mezzo and micro.The proposed definition of the nature and types of modern cross-border processes has the great theoretical and practical significance. This is evidenced, for example, in the work on quantitative and qualitative assessment oftransborder processes. Presented the basic notions of the developed system on indexation and monitoring of transborder cooperation at the new Eastern border of the European Union.

Multi-core optimization for conjugate gradient benchmark on heterogeneous processors

Developing parallel applications on heterogeneous processors is facing the challenges of 'memory wall',due to limited capacity of local storage,limited bandwidth and long latency for memory access. Aiming at this problem,a parallelization approach was proposed with six memory optimization schemes for CG,four schemes of them aiming at all kinds of sparse matrix-vector multiplication (SPMV) operation. Conducted on IBM QS20,the parallelization approach can reach up to 21 and 133 times speedups with size A and B,respectively,compared with single power processor element. Finally,the conclusion is drawn that the peak bandwidth of memory access on Cell BE can be obtained in SPMV,simple computation is more efficient on heterogeneous processors and loop-unrolling can hide local storage access latency while executing scalar operation on SIMD cores.

Visual ＂playback＂ of colorful signals in the field supports sensory drive for signal detectability

Colorful visual signals are important systems for investigating the effects of signaling environ ments and receiver physiology on signal evolution as predicted by the sensory drive hypothesis. Support for the sensory drive hypothesis on color signal evolution is mostly based on document ing correlations between the properties of signals and habitat conditions under which the signals are given （i.e., a correlational approach） and less commonly on the use of mathematical models that integrate representations of visual environments, signal properties, and sensory systems （i.e., a functional approach）. Here, we used an experimental approach in the field to evaluate signal efficacy of colorful lizard throat fans called dewlaps that show geographic variation in the lizard Anolis cristatellus. We used a remote controlled apparatus to display ＂fake dewlaps＂ to wild lizards to test for adaptive divergence in dewlap brightness （i.e., perceived intensity） among populations in situ. We found evidence of local adaptation in dewlap brightness consistent with the sensory drive hypothesis. Specifically, dewlaps that had the brightness characteristics of local lizards were more likely to be detected than those with the brightness characteristics of nonlocal lizards. Our findings indicate that simplified mathematical representations of visual environments may allow robust estimates of relative detectability or conspicuousness in natural habitats. We have shown the feasibility of evaluating color signal efficacy experimentally under natural conditions and dem onstrate the potential advantages of presenting isolated components of signals to an intended re ceiver to measure their contribution to signal function.