混合气体燃烧中爆震波传播机理的研究

对混合气体燃烧中爆震波的传播机理进行了分析研究，建立了确定爆震波速度的方法，并计算了在液体燃料（汽油、煤油）与空气混合气体燃烧中产生的爆震波特性参数，为脉冲爆震发动机的实验研究和设计提供理论依据。     

飞行状态下脉冲爆震发动机性能估计分析

在理想单循环脉冲爆震发动机分析模型的基础上,通过引入进气道建立了一定飞行状态下的自吸气的脉冲爆震发动机理论性能计算模型,研究了当飞行状态改变时,脉冲爆震发动机的性能变化趋势,计算结果表明,对给定模型,飞行高度和飞行马赫数对脉冲爆震发动机性能的影响是不一样的,决定于进气道和爆震室的推进特性,同时模型也考虑了爆震频率和爆震室直径对性能的影响,这为脉冲爆震发动机的理论设计和分析提供了一定依据。      

液态碳氢燃料旋转爆震发动机起爆过程试验研究

为了分析液态碳氢燃料/纯净空气旋转爆震发动机从点火到旋转爆震波稳定传播过程的影响因素,采用预爆震管点火进行了相关试验研究。获得了预爆震波压力、燃烧室油气比、来流总温、点火器安装方式等对旋转爆震发动机起爆过程的影响。试验结果表明：旋转爆震波起爆时间随着预爆震波压力升高而缩短;来流总温740K,变化当量比时,越接近当量比1,旋转爆震起爆时间越短;工质为当量混气时,来流总温通过影响燃油的蒸发过程进而影响旋转起爆时间,总温673K以上时,起爆时间约10ms;预爆点火器垂直安装比切向安装更快形成旋转爆震波。     

斜爆震发动机研究进展与技术挑战

斜爆震发动机（Oblique detonation engine, ODE）采用驻定斜爆震波（Oblique detonation wave, ODW）实现高超声速气流中燃料化学能向推进系统机械能的高效转化，可大幅提升吸气式飞行速域上限，具有重要发展潜力和应用价值。本文从早、中、近期3个阶段概述ODE发展历程，总结当下斜爆震燃烧及发动机的研究现状。重点从发动机设计角度综述国内外在斜爆震燃烧组织、燃料喷注掺混以及总体性能与内流设计3方面的研究进展。深入分析了总体约束下的内外流一体化设计、高超声速气流中的燃料喷注掺混、复杂来流条件下的稳定燃烧组织、高热载荷防护以及超高速工况试验条件5大技术挑战及重点关注方向，为后续深入技术攻关及应用提供参考。     

球形点火腔对脉冲爆震DDT过程影响的数值研究

为了减小脉冲爆震发动机PDE（pulse detonation engine）单次循环时间，缩短爆燃向爆震转变DDT（deflagration to detonation transition）距离是关键.为此，提出了一种在头部添加球形点火腔的新型爆震管道结构设计方案，并采用丙烷和空气为可爆混合物，通过对新型爆震管DDT过程的二维数值模拟，研究其对DDT距离以及DDT时间的影响.数值模拟结果表明，头部采用球形点火腔后，点火腔中的压缩波经过多次反射后，能够在爆震管中更快地促使爆震波形成，DDT距离大大缩短；当球形点火腔直径为1.5倍等直爆震管直径时，相对于常规等直管爆震管结构，其DDT距离和过程时间分别减少了14%和16.26%.      

Experimental investigation of characteristics of instability evolution in a centrifugal compressor

The stable range of operation for the centrifugal compressor significantly influences the dynamic, economic, and environment-friendly characteristics of power systems. A deep understanding of the characteristics of instability evolution is necessary to improve the compressor stability. A centrifugal compressor equipped with a vaneless diffuser is experimentally investigated using highresponse static-pressure measurements. The results obtained indicate that three typical rotationalspeed ranges ex...     

Leakage and wear characteristics of carbon seals for aero-engines

Experimental investigation has been performed to study the leakage and wear characteristics of carbon seal working at high circumferential speed. To expand the scope of application, two newly designed carbon seals were compared: #1 Carbon Seal (CS1) with the inner diameter of 136 mm and including 4 segments, #2 Carbon Seal (CS2) with the inner diameter of 212 mm and including 6 segments. Air leakage tests were firstly conducted in the Medium-speed Seal Test Rig. The pressure ratio changed from 1.04 to 2.02 with the rotating speed varying from 0 to 18300 r/min. Of paramount concern was the durability test, including 300 h running time accumulated by three different working conditions, which was separately implemented on each carbon seal. The morphology variation of the friction surface, wear and leakage were recorded. Results indicated that the leakage monotonously increases with the pressure ratio and decreases with the rotating speed. Comparing with CS1, more typical features exist on the friction surface of CS2, which are generated by more severe wear. Continually, leakage characteristics deteriorate. Furthermore, fitted formula has been educed for the life prediction of carbon seal, which could provide some supports for aero-engine design.     

旋转爆轰波与涡轮平面叶栅相互作用数值模拟

由于旋转爆轰燃烧室具有自增压特性，可提高热力循环效率，因此将旋转爆轰燃烧室应用于燃气轮机可进一步提高系统的性能。基于非稳态雷诺时均Navier-Stokes方法，采用剪切应力输运k-ω湍流模型，建立旋转爆轰燃烧室与涡轮平面叶栅耦合计算模型，研究旋转爆轰燃烧室内的复杂波系与涡轮叶片的相互作用，分析涡轮叶栅对高频爆轰压力振荡的抑制作用。结果表明：旋转爆轰燃烧室内的燃气在涡轮叶栅内加速，并且在斜激波后的局部区域马赫数的增加更为明显。斜激波与涡轮静转子叶片的前缘、压力面、吸力面以及尾缘相互作用，由于旋转爆轰波不同的传播方向，使得斜激波与静子叶片呈相互垂直或平行，进而形成两种不同的波系结构。涡轮叶栅对高频压力振荡存在明显的抑制作用，涡轮叶栅上下游高频压力振荡幅值的衰减率达到80%以上。研究结果展示了旋转爆轰波作用下涡轮叶栅内复杂波系结构特征，并对基于爆轰燃烧推进技术的应用提供了一定的理论基础。     

Electrochemical behavior of Ti-6.5Al-2Zr-1Mo-1V alloy under rotating condition with periodically fluctuating current density

Titanium alloy plays a crucial role in the electrochemical field due to its excellent corrosion resistance. The passivation and dissolution behaviors of Ti-6.5Al-2Zr-1Mo-1V（TA15） alloy in Na Cl solution were studied by simulating the electrochemical machining process in a rotating condition, which made the anode in a state with alternating high and low current density. Electron probe micro analysis, ultra-depth microscope, scanning electron microscope, and X-ray photoelectron spectrometer were u...     

连续旋转爆震波与涡轮静子叶栅相互作用数值研究

为了研究旋转爆震燃烧与涡轮部件组合的工作特性，对旋转爆震波与涡轮静子叶栅的相互作用过程进行了数值模拟，考虑了不同传播方向的影响，详细分析了爆震波与涡轮叶栅相互作用机理。结果表明，爆震波顺着叶盆方向传播时，在叶栅的叶盆处出现高温区，逆向传播时，同时在叶盆和叶背处都出现高温区；并且顺向传播时产生的反射波强度更大。分析了涡轮进出口压力和温度的变化过程，发现涡轮对压力的波动有一定抑制作用，顺向和逆向传播的爆震波经过涡轮叶栅后压力变化幅值分别下降了68%和57%。得到了对于当前叶栅构型，顺向传播的爆震波总压损失为11.03%，而逆向传播的爆震波总压损失为6.7%。