低压蒸汽透平排汽缸内三维粘性流动的数值模拟

采用三维粘性流场求解软件Fine／TURBO[1]对低压蒸汽透平下游排汽缸内的复杂流动进行数值模拟。计算中使用了Jameson的Runge-Kutta中心差分格式[2]和Baldwin-Lomax的代数湍流模型、计算结果同部分实验结果进行了对比,表明数值模拟揭示了排汽缸内复杂的旋涡结构,以及影响排气缸内压力恢复和总压损失的主要因素。     

燃气轮机叶轮与导叶轮之间空腔中流体速度场的研究

本文介绍燃气透平第一级叶轮前国盘空腔中的流体流动状态的研究,用可视化方法观察和分析主流气进入空腔的临界工况．采用粒子成像技术（ＰＩＶ）测量园盘空腔内的速度场,分析了密封气流量大小对不同位置流场的影响．将其结果与ＦＬＵＥＮＴ,ＣＦＤ软件的计算值相比较．     

单轴恒速回热燃气轮机的变工况解析特性及初步经济分析

本文给出单轴恒速回热燃气轮机变工况特性的显式解析解,并且总结了其变工况的典型情况;发现当对所有参数都用与其设计值的比值表达时,燃气轮机效率可以基本总结为单一曲线,并定量论证了恒速单轴燃气轮机采用回热后变工况效率反而相对有所下降。利用得出的解析解,还对采用回热的经济评价给出了初步分析,给出了采用回热合适与否的判别公式。     

Numerical modeling of flow past a volumeless and thin rigid body using direct forcing immersed boundary method

The new capability has been added as the numerical method for modeling volumeless and thin rigid bodies to the direct forcing immersed boundary (DFIB) method. The DFIB approach is based on adding a virtual force to the Navier–Stokes equations of incompressible flow to account for the interaction between the fluid and structures. The volume of a solid function (VOS) identifies the stationary or moving solid structures in a given fluid domain. A new VOS-based algorithm was developed to identify thin, rigid structure boundary points in fluid flow and ensure that the fluid cannot cross through the boundary of a thin rigid structure while moving or stationary. The DFIB method was first validated in a three-dimensional (3D) turbulent flow over a circular cylinder. The large-eddy simulation simulated the turbulent flow scales. The proposed algorithm was tested using a 3D turbulent flow past a stationary and rotating Savonius wind turbine that functions as a thin, rigid body. The validation results showed that the selected DFIB approach, combined with the novel algorithm, could simulate a thin, volumeless, rigid structure that is stationary and rotating in incompressible turbulent flows. The current method is also applicable for two-way fluid-structure interaction problems.