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汽车安全与节能学报

JASE ›› 2020, Vol. 11 ›› Issue (1): 127-134.DOI: 10.3969/j.issn.1674-8484.2020.01.014

• 汽车节能与环保 • 上一篇    下一篇

脉冲频率与幅度对两级涡轮非定常特性的影响

赵荣超 1, 2，诸葛伟林 2，马学龙 3，张扬军 2#br#   

  1. （1. 华南理工大学 机械与汽车工程学院，广东 510641，中国；
       2. 清华大学 汽车安全与节能国家重点实验室， 北京 100084，中国；
       3. 潍柴动力股份有限公司，山东 261061，中国）
  • 收稿日期:2019-09-20 出版日期:2020-03-31 发布日期:2020-04-01
  • 作者简介:第一作者 / First author： 赵荣超（1987— ），男（汉），广东，副教授。E-mail: merczhao@scut.edu.cn。
  • 基金资助:
     汽车安全与节能国家重点实验室开放基金资助项目（KF1821）；国家自然科学基金（ 51606070）；国家重点研 发计划项目（ 2016YFD0700803）；广东省自然科学基金（ 2017A030313328）。

Impacts of pulse frequency and amplitude on the unsteady characteristics of a two-stage turbine

ZHAO Rongchao 1, 2, ZHUGE Weilin 2, MA Xuelong 3, ZHANG Yangjun 2   

  • Received:2019-09-20 Online:2020-03-31 Published:2020-04-01

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摘要： 涡轮复合技术中脉冲排气对两级涡轮性能产生显著影响。为探明脉冲来流下两级涡轮非定常 特性，该文基于三维非定常流动仿真模型研究了排气脉冲频率与幅度的影响。模型中，高压级涡轮内 流动采用全通道模拟以考虑蜗壳引起的非对称流动，低压级涡轮内流动采用单通道模拟以提高计算效 率。结果表明，当脉冲频率从40 Hz 增加到 120 Hz，高压级涡轮瞬时功率峰值显著增大15.4%，而 低压级涡轮瞬时功率峰值变化在 1% 以内；随脉冲幅度增大，低压级涡轮效率下降幅度比高压级涡轮 更大，当脉冲幅度系数为 1.6 时，高、低压级涡轮转子效率分别下降 3.66% 和8.09%；低压级涡轮 转子从叶中到叶尖处的进口流动攻角在脉冲周期内大幅度变化，引起叶片前缘处产生显著流动损失。

关键词: 内燃机 , 叶轮机械 , 两级涡轮 , 脉冲流动 , 非定常特性 , 流动机理

Abstract: The pulsating exhaust in turbocompound technology significantly exerts effects on the performance of the two-stage turbine. The effects of exhaust pulse frequency and amplitude were investigated to reveal the unsteady characteristic of the two-stage turbine under pulsating flow conditions on the base of a threedimensional unsteady flow simulation model. In the model, the flows in the high-pressure turbine were modeled using full stage passage, which could consider the asymmetric flows caused by the volute. The flows in the lowpressure turbine were modelled using single passage to improve the calculation efficiency. The results show that as the frequency increases from 40 to 120 Hz, the peak instantaneous power of high-pressure stage turbine increases significantly by 15.4%, while the peak instantaneous power of low-pressure stage turbine changes within 1%. With the increase of pulse amplitude, the efficiency of low-pressure stage turbine decreases more greatly than that of high-pressure stage turbine. When the coefficient of the pulse amplitude is 1.6, the rotor efficiencies of the high- and low-pressure stage drop down 3.66% and 8.09%, respectively. The incidence angle of low-pressure turbine rotor from the middle to the tip of the blade varies significantly during the pulse period, resulting in significant flow loss at the leading edge of the blade.

Key words: internal combustion engine ,  turbomachinery , two-stage turbine ,  pulsating flow ,  unsteady characteristic , flow mechanism