小流量温度畸变发生器设计及温度畸变特性研究

发布时间：2018-06-03 02:03

本文选题：温度畸变发生器 + 氢燃料　；参考：《南京航空航天大学》2016年硕士论文

【摘要】：温度畸变发生器是航空发动机研制过程中评定发动机气动稳定性的重要设备之一,要求其能准确模拟各类温度畸变源的工作范围,研究温度畸变发生器畸变特性对航空发动机的设计及其稳定性评定具有重要的意义。本文以小流量航空发动机温度畸变发生器的工程应用为背景,采用数值模拟及试验的方法,开展小流量航空发动机温度畸变发生器的设计及工作特性研究,主要研究成果包括:(1)以小流量航空发动机进口参数为设计参数,针对以氢气为燃料、空气为氧化剂的氢燃烧式温度畸变发生器,设计了火焰稳定器和喷氢杆,喷氢杆包括顺喷和逆喷两种方案,并进行了数值模拟,结果表明两种方案均能稳定工作。(2)针对氢燃烧式温度畸变发生器的单个稳定器模型和周向90°范围模型进行了稳态点火试验研究,通过单个稳定器模型的试验表明火焰稳定器具有良好的稳焰能力,随着供氢压力的升高,温升值也逐渐增大,随着进口流量增加贫油点熄火极限逐渐增加;通过周向90°范围模型的试验研究表明,顺喷和逆喷结构总压恢复系数均大于0.98,总压不均匀度均小于2%,两种结构的温度分布不均匀度均在15%以下,且顺喷结构获得的温升值大于逆喷结构获得的温升值。(3)建立单个稳定器的计算模型,采用数值模拟方法研究了其稳态燃烧过程,其中燃烧化学反应模型采用总包反应和9组分20步的氢气基元反应进行对比研究,并与试验结果进行对比。结果表明基元反应结果与试验结果相近,因而选取基元反应为化学反应模型。建立不同周向范围及加入压气机的氢燃烧式温度畸变发生器的计算模型,研究氢燃烧式温度畸变发生器稳态和非稳态燃烧过程。结果表明:温度畸变场的温升值和温度不均匀度变化在距离稳定器600mm的截面位置开始趋于稳定,经过压气机之后,畸变场畸变强度减小,温度周向不均匀度也略微减小,高温区范围变化不大,但位置发生了明显的偏移,同时发现较高的温度畸变会在压气机出口诱发产生漩涡,造成压气机内流动不稳定;相间位置的两个加热单元工作时获得的高温区范围略大于相邻位置获得高温区范围;供氢压力越大,温升率越大,而缓冲容积越大,温升率越小。(4)探索了热射流式温度畸变发生器初步方案设计,采用数值模拟方法对设计模型进行了初步研究。在热流进口温度为1500K的条件下,热射流式温度畸变发生器能在出口获得300K的面平均温升,温度不均匀度在15%以内。
[Abstract]:Temperature distortion generator is one of the important equipments for evaluating the aero-engine aerodynamic stability in the development of aero-engine. It is required to simulate the working range of all kinds of temperature distortion sources accurately. It is of great significance to study the distortion characteristics of temperature distortion generator for the design and stability evaluation of aeroengine. In this paper, based on the engineering application of small flow aero-engine temperature distortion generator, the design and working characteristics of small flow aero-engine temperature distortion generator are studied by numerical simulation and test. The main research results include: (1) taking the inlet parameters of small flow aeroengine as design parameters, a flame stabilizer and a hydrogen injection rod are designed for the hydrogen combustion temperature distortion generator with hydrogen as fuel and air as oxidant. The hydrogen injection rod consists of two schemes, one is the direct injection and the other is the reverse jet, and the numerical simulation is carried out. The results show that both schemes can work stably. (2) A steady ignition experiment is carried out for a single stabilizer model and a circumferential 90 掳range model for a hydrogen combustion temperature distortion generator. The experiments of a single stabilizer model show that the flame stabilizer has a good flame stabilizer ability, with the increase of hydrogen supply pressure, the temperature rise gradually increases, and the limit of quenching of lean oil point increases with the increase of inlet flow rate. The experimental results of the circumferential 90 掳range model show that the total pressure recovery coefficient is greater than 0.98, the total pressure unevenness is less than 2, and the temperature distribution unevenness of the two structures is below 15%. Moreover, the temperature rise obtained by the injection structure is higher than that obtained by the reverse jet structure. (3) the calculation model of a single stabilizer is established, and the steady combustion process of the stabilizer is studied by means of numerical simulation. The combustion chemical reaction model was compared with the experimental results by using the total package reaction and the hydrogen radical reaction of 9 components and 20 steps. The results show that the results of the elementary reaction are close to the experimental results, so the elementary reaction is chosen as the chemical reaction model. The calculation model of hydrogen combustion temperature distortion generator with different circumferential range and compressor was established to study the steady and unsteady combustion process of hydrogen combustion temperature distortion generator. The results show that the temperature appreciation of temperature distortion field and the variation of temperature inhomogeneity begin to stabilize in the section position of the distance stabilizer 600mm. After the compressor, the distortion intensity of the distortion field decreases and the temperature circumferential unevenness decreases slightly. The range of high temperature has little change, but the position has obvious deviation. At the same time, it is found that the higher temperature distortion will induce vortex at the compressor outlet, resulting in the flow instability in the compressor. The range of the high temperature region obtained by the two heating units at the interphase position is slightly larger than that obtained from the adjacent position. The higher the hydrogen supply pressure, the greater the temperature rise rate and the larger the buffer volume. The lower the temperature rise rate is, the preliminary scheme design of the thermal jet temperature distortion generator is explored, and the design model is studied by numerical simulation method. At the inlet temperature of 1500K, the thermal jet temperature distortion generator can obtain an average temperature rise of 300K at the outlet, and the temperature inhomogeneity is less than 15%.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V263.3

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