船用燃气轮机动力涡轮可调导叶级的流场结构

基于耦合求解可压缩Favre平均Navier-Stokes方程及Menter的Baseline（BSL）双方程湍流模型．本文对一个考虑可调导叶设计的船用燃气轮机变几何动力涡轮进行了全流场的三维粘性数值模拟。计算结果表明，采用可调导叶技术，涡轮各级热力反动度发生了明显变化；可调导叶级的流动特性变化更显著影响变几何动力涡轮的气动性能；选取具有良好冲角适应性和跨音速性能的可调导叶是船用燃气轮机变几何动力涡轮气动设计的一个关键技术。由此，根据数值计算结果．重点分析可调导叶级的气动特性及其流场结构。

The Flow Field Structure of the Power-turbine Variable-area Nozzle Stage of a Marine Gas Turbine

Based on the coupled solution of a compressible Favre-averaged Navier-Stokes equation and Menter baseline(BSL)dual-equation turbulence-flow model the authors have conducted a full flow-field three-dimensional viscous numerical simulation of a variable-geometry power turbine, taking into account a variable-area nozzle design. Computational results indicate that with the use of the variable-area nozzle techniques there occurred a significant change in the thermodynamic reaction of the various stages of the turbine. The change in the flow characteristics of the variable-area nozzle stage can more markedly influence the aerodynamic performance of the variable-geometry power turbine. The selection of a variable-area nozzle with fine adaptability to incidence and a good transonic performance represents a key technology of variable-geometry power turbine design for a naval gas turbine. In view of this, on the basis of the numerical calculation results, the authors' analysis has been focused on the aerodynamic performance and the flow field structure of the variable-area nozzle stage.