利用200 MW高温燃气流风洞,开展1:1全尺寸舱段模型热结构/热匹配试验.围绕风洞试验状态调节、介质影响热流设计评估、多台阶长时间热流校测等技术问题,开展高温燃气流风洞舱段类模型试验设计方法研究.引入新的燃气流风洞试验状态调节方法和考虑燃气介质差异的等效冷壁热流修正方法,并通过长时间变工况表面热流测试方法的建立,实现了多工况同步流场校测.试验设计方法有效应用于全尺寸舱段模型热结构/热匹配试验研究中.经试验验证,所建立的长时间大功率燃气流风洞试验设计方法有效可行,实现了全尺寸舱段飞行热环境的有效模拟.

为保证200 MW燃气流风洞高压氧气系统安全运行,从初始能量出发,对高压氧气系统充气、供气、排气时管道内的激波管流动、绝热压缩等过程进行安全分析,并提出针对性安全措施.结果表明:对于充气管道内存在的激波管流动,当驱动气体压力为20 MPa、被驱动气体压力为0.1 MPa时,激波反射后末端气体温度远远高于200℃,通过减小阀门开启速度,对阀前管道进行充气以减小上下游压差,可避免因绝热压缩产生的高温;供气管道充填时,管道内最高温度为73℃,通过控制充填速度,可进一步降低管道内氧气温度;通过高压排气、低压排气2种模式,可满足国标中对氧气流速的要求.研究结果可为氧气管道远程安全操作提供参考.

采用塞块式量热计对200MW燃气流风洞试验件表面热流进行测量,试验过程中塞块式量热计遍历风洞的启动、模型变攻角、停车等阶段.为准确获取不同攻角条件下模型表面热流值,采用数值仿真对塞块式量热计的传热特性进行分析,研究背温反算的热流值与输入热流边界条件的差异,提出塞块式量热计长时间使用的修正方法,该修正方法通过一次稳态热流源的标定即可获得其他热流边界条件下的结果,从而简化标定过程.将修正方法应用于长时间变工况热流测量修正时,偏差小于2％,增加了塞块式量热计的使用范围,通过一次风洞试验,获取多个稳态工况条件下试验件表面热流值,节约风洞运行成本.此外,该修正方法也可用于高热流瞬时测量结果的修正.

高温风洞是开展飞行器热防护技术研究的重要试验设备.为满足在高温风洞前端长时间生成大尺度、高焓、高速气流的试验需求,提出了一种基于气氧/煤油燃烧的高温流场生成装置.装置采用火炬式点火器点火启动,通过使用气液同轴离心喷嘴以及分区隔板的喷注器进行燃烧组织,并由可替换的型面射流喷管实现大尺度均匀流场的生成.30kg/s量级加热装置千秒热试车调试结果表明,该装置能够实现快速点火并长时间维持大尺度稳定流场的生成,在飞行器热防护地面试验技术领域将有良好的应用前景.

A numerical simulation and experimental measurements are performed to characterize the flowfield of oxygen/oil gas-jet facility. Chemical non-equilibrium Navier-Stokes equations have been solved to acquire the axisymmetric combustion-heated stream condition. The numerical results indicate that chemical reactions have an impact on flow oscillation, which alleviate the rate of decay of flow and make shock region move downstream. Flow diagnostics has been conducted to measure flow properties. Distributions of the pressure, temperature and Mach number along the centerline of the exit plane are experimentally obtained. The comparison has been presented between simulation and measurement. Static pressure distribution measurements show a good agreement with the numerical results. The computed temperatures are higher than measured ones, but the trends of oscillation and declension are nearly the same. Possible reasons of the difference are mainly because of uncertainly in chamber pressure and combustion efficiency.

The combustion gas tunnel is one of the main equipment used in the ground-test of the thermal protection system of supersonic aircraft. The assessment of the thermal protection system requires high uniformity of the flow field in the test system. The degree of matching between the pressure in the test cabin and the outlet pressure of the nozzle is a key factor affecting the uniformity of the flow field. The combustion reaction equations and CFD-FASTRAN are used to simulate the thermal environment of the gas tunnel. The gas component derived from the combustion reaction can provide a mixed gas model for numerical simulation. The shock wave characteristics of gas jet on the surface of a hemispherical-nose and cone body model are analyzed. The effects of different cabin pressures on the thermal environment of the model were analyzed. A new method for matching cabin and jet pressures is proposed.

针对高温风洞中扩压器前段壁面防热问题,提出对高温气流外缘喷水降温的方法.通过在收集器入口与喷管出口间安装喷水环,利用液态水汽化吸热对高温气流进行降温,使扩压器壁面形成低温保护层.为了解该方法降温效果,本文利用DPM、组分输运等模型的耦合建立了超声速两相流CFD模型,对向超声速热气流喷水进行降温的过程进行了数值计算,计算结果表明,扩压器启动后有显著的降温保护效果.同时,为探索风洞排气背压和喷水量对风洞流场和壁面降温效果的影响,通过计算得出了变排气背压、变喷水量与降温效果之间的关系,为高温风洞收集口喷水降温装置的优化设计提供了参考.

Objective To solve the thermal protection of hypersonic vehicle rudder and wing leading edge and nose-cones, etc, in severe aerodynamic thermal environment.Methods A metallic experimental model of theR=5 mm leading edge was designed and fabricated with high temperature liquid alloy according to the active heat transfer technology. A set of profiled quartz lamp heater and heat flux test model was designed and manufactured to carry out thermal environ-ment simulation test on thermal environment on the ground.Results The metallic experimental model had transient start characteristics at 530℃ of leading edge center. The maximum radiant heat flux at the center of the leading edge and the surface was 1000 kw/m2 and 580 kw/m2 respectively. The model had the advantages of good heat conduction ability. The specimen had no medium leakage and structure damage after test, they had certain repeatability.ConclusionIt can be used to further engineering design and application in combination with existing mature thermal protection technology.

In order to provide necessary design parameters for design of the oxygen/kerosene engine and thermal protection, thermodynamic calculation of oxygen/kerosene gas is studied in this paper. The minimization Gibbs free energy calculation model was used to determine equilibrium compositions. The thermodynamic parameters and transport coefficients were derived with a fitting method of formulas. The variation characteristics of equilibrium compositions, and thermodynamic parameters and transport coefficients of oxygen/kerosene gas with pressure and temperature were obtained. The analysis results indicate that hydrolytic dissociation has an significant impact on the equilibrium compositions, and the pressure increase may cause the rising of the initial temperature of hydrolytic dissociation; the pressure began to affect thermodynamic and transport properties seriously after hydrolytic dissociation at high temperature; the diffusion coefficient of components in fuel gas are influenced by the combined effect of temperature and mole fractions. Thermal conductivity has a great effect on Prandtl number. After H2O is dissociated,Prandtl number reduces fast as the thermal conductivity increases quickly.

Research on the measurement of low loss dielectric material for high temperature, the principle of complex permittivity measurement of low loss dielectric material for high temperature by short wave-guide method is summarized, material selection and design of high temperature waveguide is analyzed, the high temperature complex permittivity of low loss dielectric materials applied on some random and antenna window material is measured. The results were satisfactory and the temperature could measure accurately from room temperature to 1600℃.

A kind of semiconductor refrigeration is tested and analyzed, which is used for the active thermal control design of spacecraft. The test method and test data in different operation conditions are given, and the relationships between current and voltage, temperature difference, refrigerating capacity are analyzed. Based on test data, the thermoelectricity parameters of semiconductor refrigeration are calculated and evaluated, and the active thermal control of some space vehicle is designed.

In order to verify the thermal insulation performance of the reusable carrier and used by the hypersonic aircraft thermal protection system under the huge total heat conditions,the theoreticd analysis of flat-type quartz lamp heater radiant heat environment was carried out.On this basis,a set of thermal environment simulation equipment for the ground assessment test of the thermal protection performance of the aircraft thermal protection system was designed and manufactured,and a matching energy,measurement and control system was built.The thermal test was carried out from room temperature to 800 ℃ for hot and cold alternating load,the thermal boundary simulation test at 50 ℃ /s temperature rise rate,the batch thermal environment loading test,and the single heat source temperature zone nonlinear aerodynamic thermal environment equivalent simulation test and other typical applications were carried out with the use of this system.The stability of the heating system,the uniformity of the temperature distribution in the heat radiation area and the reliability of the measurement and control system are verified.It shows that the test system can meet the practical requirements of many kinds of anti-heat insulation test.

本文采用Monte-Carlo法(MCM),对用于防/隔热材料筛选或性能考核试验的平板型石英灯加热器热环境(辐射特性)进行了分析.重点对石英灯加热器中水冷反光板面积、水冷反光板与灯阵间距离、热源疏密程度、热源阵列与材料受热面间距等因素对辐射热场中典型隔热材料受热表面温度分布均匀性和热流密度进行了模拟计算.

In order to study the pressure peak caused by deflagration in starting process of gas jet heater, a simulation method was carried out. The deflagration simulation was divided into cold-test and hot-test processes. The mass conservation equation, energy conservation equation and oxygen/oil combustion reaction equation were used to analyze the pressure of combustion chamber in both cold-test and hot-test. The analysis results suit well with the prototype test which shows the applicability of the method. Based on this method, peak pressure of the deflagration under a given condition was calculated. The peak pressure calculated (13.5MPa) exceeded the design pressure (5Mpa), which led to the damage of the gas jet heater.

The thermal protection test can be done by high temperature and supersonic gas jet, which plays an important role in promoting global thermal protection system development over the past few decades. The principle, characteristics and applications of the test method are presented. Furthermore, the development of thermal protection technology for high supersonic air vehicle in the future is analyzed, and how to adapt the aforementioned development for gas jet test is suggested accordingly.

为实现高热流环境下高温燃气流超声速风洞系统的重复使用,采用数值方法对扩压器热环境进行了分析,采用沸腾换热方法对扩压器进行了热防护设计,并通过试验验证了沸腾换热理论应用的可行性.结果表明,沸腾换热在水流速2 m/s的情况下可实现热流2 MW/m2的热防护,应用沸腾换热可以有效降低设计难度,在较低的速度和压力损失下达到更好的换热效果.

This paper proposes a new method for measuring the high heat flux of a long duration. The heat sink is made of phase change materials (PCMs) and metal honeycomb materials with high thermal conductivity. The PCMs, with high latent heat, are used to absorb the heat continuously, which is received by the heat flux meter, then the heat flux as high as 1MW·m-2 can be measured for a duration longer than 2000s. An apparent heat capacity method is adopted to establish the analytical model for the measurements of high heat flux of a long duration. The model is validated by the experimental results and is used to study the influence of the physical properties of PCMs on the measuring method. The physical parameters include the thermal conductivity, the phase change latent heat and the phase transition temperature. It is shown that phase change material of higher heat sink thermal conductivity, lower phase transition temperature higher than the initial environmental temperature, and larger latent heat is suitable for measuring high heat flux of a long duration.

对用于防热系统试验考核的高温超声速燃气流场的流场结构和热环境特性进行了计算和分析.将CFD模拟方法与工程计算方法相结合,对两类锥形喷管形成的燃气流场进行了数值模拟计算和流场结构分析,并与试验过程中高速拍摄的图片进行了比对.利用模拟得到的流场气动参数,计算了沿流场轴向位置球头驻点模型的热流和压力,并与试验测量数据进行了对比,结果吻合较好.锥形喷管形成压缩波和膨胀波交替的流场结构,导致流场气动参数与模型热流和压力形成正弦变化的特点.