铝箔轧制加氢基础油化学组成与抗氧化性能关系的研究

选用5种国内常用的低硫、低芳烃铝箔轧制加氢基础油,在GCMS-QP2010型气相色谱质谱联用仪上分析其化学组成,并采用紫外分光光度法测定油样中的微量芳烃,在SH0206变压器油氧化安定仪上测定油品的抗氧化性能。试验结果表明:铝箔轧制加氢基础油化学组成与油品的氧化安定性有密切的关系,高环烷烃基础油的抗氧化性能较差,而低环烷烃基础油的抗氧化性能较好,油品中正构烷烃的含量越高,其氧化安定性就越好。添加抗氧剂能显著提高基础油的氧化安定性,并使高环烷烃基础油抗氧化性能达到低环烷烃基础油的水平。

Dissipative free-surface solver for potential flow around hydrofoil distributed with doublets

A doublet integral equation is formulated for the two-dimensional dissipative potential flow around a hydrofoil submerged below a free-water surface. The free-water surface is assumed to involve energy dissipation, and thus it is the source of damping. A doublet panel method is developed from incorporation of the dissipative Green function approach and the doublet distributions on the hydrofoil surface. Numerical computations are implemented, and the derived numerical results are in good agreement with analytic solutions and experimental measurements.