【摘要】 车用增压器双通道涡轮进口气流是脉动不同步变化的,基于稳态方法设计的涡轮在实际运行条件下的性能与其稳态性能存在差异。为了解异相脉冲进气条件下涡轮性能,改善涡轮与发动机的匹配,本文使用数值模拟的方法对最大扭矩工况对应的40 Hz脉冲频率进气条件下涡轮内部流场进行了研究。结果表明:涡轮入口两个通道内压力越不均衡,涡轮的效率和流通能力越低,叶轮入口攻角变化对叶轮流场影响很大,进口攻角随叶高变化,且与涡轮级入口压力水平有关,脉冲波还会影响吸力面的气体分离涡团。更多还原

【Abstract】 The inlet pulsation in twin-entry turbine on automotive turbocharger was not synchronized.The performance of the turbine designed on steady changed when working under actual condition.To achieve higher efficiency,the numerical simulation was used to study the flow field of turbine when the pulse frequency was 40 Hz.The results showed that the more unbalance of the pressure between the two channels was,the worse the efficiency and flow capacity of the turbine were.The variation of the incidence angle had great influence on turbine rotor flow field.The incidence angle at the rotor inlet varied along leading edge,its value was also related to the inlet pressure of the turbine stage.Besides,the pulse wave mainly affected the separation flow on suction surface.更多还原