本文選題：航空發(fā)動(dòng)機(jī) + 電容層析成像��； 參考：《中國(guó)民航大學(xué)》2016年碩士論文

【摘要】：航空發(fā)動(dòng)機(jī)(aero-engine)作為飛機(jī)的重要組成單元,它的結(jié)構(gòu)復(fù)雜特殊,運(yùn)行環(huán)境惡劣,工作狀態(tài)切換頻繁。這些因素都極易給發(fā)動(dòng)機(jī)帶來(lái)磨損和損耗,嚴(yán)重時(shí)會(huì)導(dǎo)致其工作失效,造成航空事故,危害飛機(jī)的飛行安全和人的生命安全。因此對(duì)飛機(jī)尾氣的監(jiān)測(cè)具有重大意義。本文利用電容層析成像(Electrical Capacitance Tomography,ECT)技術(shù)對(duì)模擬aero-engine尾噴管處的尾氣進(jìn)行氣路監(jiān)測(cè),以獲取實(shí)時(shí)圖像,監(jiān)測(cè)尾管內(nèi)氣固兩相流的流動(dòng)情況和顆粒信息,為發(fā)動(dòng)機(jī)維修提供參考依據(jù)。ECT技術(shù)是目前最為成熟的一種電學(xué)層析成像(Electrical Tomography,ET)技術(shù)。該技術(shù)具有無(wú)輻射、非侵入、可靠性高、實(shí)時(shí)性強(qiáng)以及成本低等優(yōu)勢(shì),但因空間分辨較低所以在稀相流的測(cè)量中應(yīng)用較少。為了深入研究aero-engine的尾氣情況,以便對(duì)aero-engine做出故障診斷,本文研制了一套ECT硬件采集系統(tǒng),通過(guò)ECT技術(shù)對(duì)aero-engine尾氣進(jìn)行測(cè)量研究,做的主要工作以及獲得的結(jié)果如下:1.分析研究并吸收ECT傳感器的研究成果,根據(jù)aero-engine噴尾管實(shí)際模型和傳感器結(jié)構(gòu)優(yōu)化,設(shè)計(jì)了一套基于16電極的圓周形ECT傳感器。2.通過(guò)分析ECT傳感器物理敏感場(chǎng)的特性,提出其數(shù)學(xué)描述,并通過(guò)二維有限元方法求解ECT的正問(wèn)題以及分析ECT的逆問(wèn)題。3.研制一款16電極圓周形傳感器的ECT硬件采集系統(tǒng)。該系統(tǒng)是在吸收前人研究的基礎(chǔ)上進(jìn)行改進(jìn),采用Xilinx的FPGA作為核心處理控制單元,通過(guò)數(shù)字解調(diào)的方法,提高了系統(tǒng)的實(shí)時(shí)性;在輸入信號(hào)頻率和幅值不變時(shí),采用量程更小和轉(zhuǎn)換速度更快的ADC;系統(tǒng)PCB的布局,融入了信號(hào)完整性(Signal Integrity,SI)、電源完整性(Power Integrity,PI)以及電磁兼容性(Electro Magnetic Compatibility,EMC)的設(shè)計(jì)理念,使系統(tǒng)硬件設(shè)計(jì)更加合理,優(yōu)化程度更高。4.借助線性反投影算法(Linear Back Projection,LBP)和Landweber迭代算法兩種經(jīng)典ECT成像算法,再結(jié)合設(shè)計(jì)的ECT硬件采集系統(tǒng),進(jìn)行實(shí)時(shí)成像,從而驗(yàn)證硬件采集系統(tǒng)和軟件系統(tǒng)的性能。結(jié)果表明,該系統(tǒng)性能穩(wěn)定、重建圖像清晰可見(jiàn)以及可拓展性強(qiáng)。
[Abstract]:Aero engine (aero-engine) as an important component of the aircraft, its structure is complex and special, harsh working environment, working condition of frequent switching. These factors are easy to bring the engine wear and tear, it will lead to serious failure, caused by aviation accidents, endangering flight safety and the safety of human life. So monitoring the aircraft exhaust is of great significance. This paper using electrical capacitance tomography (Electrical Capacitance Tomography ECT) technology to simulate aero-engine exhaust nozzle of gas path monitoring, to obtain real-time image monitoring, the tail pipe of gas-solid two-phase flow in the flow and particle information, provide reference for engine maintenance technology is.ECT at present, one of the most mature electrical tomography (Electrical Tomography ET) technology. This technology has no radiation, non-invasive, high reliability, real-time and The advantages of low cost, but because of low spatial resolution measurement so in dilute phase flow in application. In order to study the emission of aero-engine, in order to make fault diagnosis of aero-engine, this paper develops a set of ECT hardware acquisition system was studied by ECT technology of aero-engine tail gas, the main work done and get the the results are as follows: 1. research results and analysis of the absorption of the ECT sensor, according to the aero-engine model and the actual injection tail pipe sensor structure, design a set of circle shaped ECT sensor.2. 16 electrode based on ECT sensor by analyzing the physical characteristics of sensitive field, put forward the mathematical description, and through the two-dimensional finite element method to solve the problem is ECT and ECT analysis of the inverse problem of.3. development of a 16 electrode circle sensor ECT hardware acquisition system. The system is on the basis of previous studies Improved, using Xilinx FPGA as the core processing control unit, through the method of digital demodulation, improves the real-time performance of the system; the frequency and amplitude of the input signal is constant, the range of smaller and faster switching speed ADC; PCB system layout, integrated signal integrity (Signal Integrity SI), power integrity (Power Integrity, PI) and electromagnetic compatibility (Electro Magnetic, Compatibility, EMC) design concept, the system hardware design is more reasonable, optimize the higher degree of.4. with the linear back projection algorithm (Linear Back Projection, LBP) two classic ECT imaging algorithm and Landweber iterative algorithm, combined with the ECT acquisition system hardware design. Real time imaging, so as to verify the performance of the hardware system and software system. The results show that the system has stable performance, the reconstructed image is clearly visible and strong expansibility.

【學(xué)位授予單位】：中國(guó)民航大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2016
【分類號(hào)】：V263.6;TP274
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本文編號(hào)：1737276