航空学报 > 2022, Vol. 43 Issue (9): 125907-125907   doi: 10.7527/S1000-6893.2021.25907

燃气涡轮发动机预旋系统压比和熵增的作用机制与理论分析

林阿强1,2, 刘高文1,2, 吴衡3, 畅然1, 冯青1,2   

  1. 1. 西北工业大学 动力与能源学院, 西安 710129;
    2. 西北工业大学 陕西省航空动力系统热科学重点实验室, 西安 710072;
    3. 新奥能源动力科技(上海)有限公司, 上海 200241
  • 收稿日期:2021-06-03 修回日期:2021-06-30 出版日期:2022-09-15 发布日期:2021-09-06
  • 通讯作者: 刘高文,E-mail:gwliu@nwpu.edu.cn E-mail:gwliu@nwpu.edu.cn
  • 基金资助:
    国家科技重大专项(2017-Ⅲ-0011-0037); 中央高校基本科研业务费专项资金(3102021OQD701)

Mechanism and theoretical analysis of pressure ratio and entropy increase in a pre-swirl system of gas turbine engine

LIN Aqiang1,2, LIU Gaowen1,2, WU Heng3, CHANG Ran1, FENG Qing1,2   

  1. 1. School of Power and Energy, Northwestern Polytechnical University, Xi 'an 710129, China;
    2. Shaanxi Key Laboratory of Thermal Science in Aero-engine System, Northwestern Polytechnical University, Xi 'an 710072, China;
    3. ENN Energy Power Technology (Shanghai) Co., LTD, Shanghai 200241, China
  • Received:2021-06-03 Revised:2021-06-30 Online:2022-09-15 Published:2021-09-06
  • Supported by:
    National Science and Technology Major Project of China (2017-Ⅲ-0011-0037); Fundamental Research Funds for the Central Universities (3102021OQD701)

摘要: 预旋供气系统作为涡轮转子高温热防护的重要保障, 具有复杂转静部件的功热转换问题。重点开展理论分析, 详细揭示了预旋供气系统压比、熵增和温降特性的关联机制和演化规律, 提出压比效率的数学模型, 并综合评估转动部件叶轮效应的影响机制。通过公式推导和理论分析表明, 在绝热定比热条件下, 静子系压比和熵增均随供气流量增加而单调递减。转子系压比-熵增特性取决于供气流量、转盘转速和系统温降的影响。将复杂系统温降的关联式分解为速度系数和转子马赫数的强关联函数, 明确指出系统压比随供气流量增加而减小, 并随转盘转速增加基本呈现增大趋势。当预旋喷嘴旋转比大于预旋半径比的倒数时, 随着转盘转速增大, 系统压比反而减小。在来流工况和预旋半径比不变时, 预旋供气系统内降低熵增损失是提高系统压比的重要途径。通过系统地评估转动部件叶轮效应发现, 在不改变转子马赫数且保证系统压比不变的条件下, 叶轮效应可以提高喷嘴出口速度系数, 增大系统温降, 并降低系统功耗。因此, 压比和熵增特性的关联机制可以有效评估预旋供气系统性能设计的优劣。

关键词: 涡轮盘腔, 预旋供气系统, 压比效率, 熵增, 叶轮效应, 预旋半径比

Abstract: The pre-swirl system has the complex problem of power and heat conversion of rotating and stationary components, and can provide important guarantee for high-temperature thermal protection of turbine rotating blade. Theoretical analysis of the correlation mechanism and evolution law of pressure ratio, entropy increase, and temperature drop of the pre-swirl system is conducted in this paper. A mathematical model of pressure ratio efficiency is proposed. The influence mechanism of the impeller effect of rotating component is comprehensively evaluated. It is found that under the condition of adiabatic constant specific heat, the pressure ratio and entropy increase of the station system decreases monotonously with the increase of air supply flow rate. The pressure ratio-entropy increase characteristic of rotor system depends on the effect of air supply flow rate, rotational speed of turbine disc, and system temperature drop. By decomposing the mechanism of temperature drop into a strong correlation function between the velocity coefficient and the rotating Mach number, it is clearly pointed out that the system pressure ratio decreases with the increase of the air supply flow rate, and basically increases with the increase of the turbine disc rotational speed. When the airflow swirl ratio of pre-swirl nozzle is greater than the reciprocal of pre-swirl radius ratio, the system pressure ratio decreases with the increase of turbine disc rotational speed. It can be revealed that the decrease of entropy loss is an important way to improve the system pressure ratio when the inlet flow condition and the pre-swirl radius ratio are constant. By systematically evaluating the impeller effect of rotor component, it is found that the impeller can increase the nozzle outlet velocity coefficient, increase the system temperature drop, and reduce the system power consumption without changing the rotating Mach number and keeping the system pressure ratio unchanged. Therefore, the correlation mechanism of pressure ratio and entropy increase characteristics can effectively evaluate the design of pre-swirl system.

Key words: turbine disc cavity, pre-swirl system, pressure ratio efficiency, entropy increase, impeller effect, pre-swirl radius ratio

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