超声速燃烧室壁面压力特征实验研究 *

Experimental Investigationon WallPressure Characteristicin Hypersonic Combustor

关键词:  超燃冲压发动机  燃烧室  闭环控制  压力响应

Key words:  Scramjet  Combustor  Closed-loop control  Pressure response

摘要:

为了评估基于燃烧室壁面压力实时监控的双模态超燃冲压发动机闭环控制系统方案的可行性，在西北工业大学地面直连式实验台上开展了一系列双模态超燃冲压发动机燃烧室地面直连式实验。实验模拟了飞行马赫数4.0条件下两个不同燃烧室构型点火燃烧的实际工作过程，测量并分析了燃烧室壁面压力脉动、压力响应和激波串前沿位置等特征。燃烧室进口来流状态为马赫数 2.0、总温约 880K、总压 0.8～1MPa。实验结果表明，燃烧室壁面压力存在明显脉动，且脉动幅度随着油气比的增加呈现增加趋势；壁面压力响应很快，响应时间在毫秒量级，说明在超燃冲压发动机闭环控制中，通过燃烧室实时壁面压力反馈来调节供油控制燃烧室工作状态是可能的；另外，通过改变燃油流量能够实时控制隔离段激波串前沿位置。

Abstract:

To estimate the feasibility of a scramjet closed-loop control system which is based on the dualmode scramjet combustor wall pressure real-time monitoring，a series of dual mode scramjet combustor direct-connected experimental studies were conducted by using the direct-connected facility of Northwestern Polytechni.cal University(NWPU). The actual working process was simulated and two different scramjet combustor modelswere used. The characteristics of combustor wall pressure fluctuation，pressure response time and shock train lead.ing edge location are measured and analyzed. The typical flow conditions at combustor entrance are: Ma=2.0，to. tal-temperatureTt≈880K and total-pressurept=0.8～1MPa，which correspond to a Mach 4.0 flight condition. Ex.perimental results indicated that in scramjet combustor pressure fluctuation is obvious and pressure pulsation am.plitude will increase if the fuel supplies increase. Pressure response is soon，the response time is in millisecondsscale so it is possible to use wall pressure as the feedback parameter in the scramjet fuel supple closed-loop con.trol. Furthermore，the shock train leading edge location can be real-time controlled by adjusting the fuel flowrate.