轴流涡轮基元级静叶稠度特性的数值研究

针对不同静叶稠度(静叶叶片数)的轴流涡轮基元级进行了非定常数值模拟,研究了静叶稠度对涡轮基元级流动状态和损失情况的影响.结果表明静叶稠度的改变对涡轮基元级流动状态和损失的影响直接与动叶稠度相关.静叶稠度的改变影响通过涡轮基元级的流量,在动叶稠度不变时,会引起涡轮基元级反力度的改变.静叶稠度增加到一定程度时,会使气流在静子中的膨胀加速过于剧烈而产生激波损失及激波与边界层干涉带来的边界层分离损失.静叶稠度减少到一定程度时,会使转子中的流动状态极大恶化,进口极大的负攻角致使动叶压力面发生大范围的分离.存在一个最佳的静叶稠度,使涡轮基元级的损失最小. 

Numerical study on the stator solidity characteristics of axial turbine element stages

For different stator solidity(vane count),an unsteady numerical simulation of turbine element stages was conducted to investigate the influence of stator solidity on the turbine element stage flow and loss status.Results indicate that the stator-solidity-change effects on the turbine element stage flow and loss status were directly associated with the rotor solidity.The change of stator solidity influenced the mass flow rate through the turbine element stage.With rotor solidity fixed,the turbine element stage reaction would change.When the stator solidity increased to a certain extent,shock loss would arise from gas excessive expansion in the stator region,as well as boundary layer separation loss caused by the interference of the shock and boundary layer.When the stator solidity reduced to a certain extent,the flow in the rotor would be greatly deteriorated,with an overlarge negative incidence angle caused great range of separation on the rotor pressure side.There’s one best stator solidity,resulting in the least turbine stage loss.