The Experimental Study of Injection and Mixing of the Model Ejector Rocket

专门设计了可用于研究箭基组合循环发动机(RBCC)在起动阶段(Ma=0)所使用的引射火箭性能的实验装置.作为初步试验,研究了不同工况的引射热喷流(一次流)和被引射空气(二次流)之间混合的演变、发展过程,找出不同来流条件下影响引射性能的主要参数,为最终探明引射火箭的最佳工作条件打下基础,同时根据试验结果提出了促进一、二次流混合的可行方案,便于下一步深入研究.

激光诱发活塞的热负荷

活塞的热疲劳性能对柴油发动机的全寿命至关重要。由于能量有限和可控性差等缺点，现有实验系统均不能满意地进行活塞热负荷模拟实验。为此，提出并建立了一套激光诱发活塞热负荷的实验系统。该系统通过对激光束的空间整形，使之投射到活塞表面后诱发的温度场分布满足特定要求。基于PROFIBUS-DP现场总线技术实现了系统集成和实验过程的全反馈控制。针对活塞的典型热负荷条件，即高周热疲劳和热冲击分别进行实验，以模拟正常工作循环和“启动一停车”等热负荷或转速突变工况。通过设置加热一冷却周期或上限下限温度，可以获得相应的热负荷模拟实验效果。研究结果表明，采用经光束整形的激光进行活塞热负荷模拟实验具有周期短、可控性好等优点。 

Energy Conversion in Shape Memory Alloy Heat Engine Part I: Theory

Shape Memory Alloy (SMA) can be easily deformed to a new shape by applying a small external load at low temperature, and then recovers its original configuration upon heating. This unique shape memory phenomenon has inspired many novel designs. SMA based heat engine is one among them. SMA heat engine is an environment-friendly alternative to extract mechanical energy from low-grade energies, for instance, warm wastewater, geothermal energy, solar thermal energy, etc. The aim of this paper is to present an applicable theoretical model for simulation of SMA-based heat engines. First, a micro-mechanical constitutive model is derived for SMAs. The volume fractions of austenite and martensite variants are chosen as internal variables to describe the evolution of microstructure in SMA upon phase transition. Subsequently, the energy equation is derived based on the first thermodynamic law and the previous SMA model. From Fourier’s law of heat conduction and Newton’s law of cooling, both differential and integral forms of energy conversion equation are obtained.

固体火箭发动机柔性接头弹性件力学性能研究

针对固体火箭发动机柔性接头中的橡胶材料，研究了在进行这种橡胶结构有限元计算中橡胶材料的力学行为的表征。进行了单轴拉伸与简单剪切材料力学性能试验，根据不同材料模型对试验曲线进行了拟合，并用MSC／Marc软件模拟了超弹性材料的单轴拉伸与简单剪切变形过程。结果表明：采用单轴拉伸试验数据预测材料剪切性能会造成明显误差，而简单剪切试验得到的模型可以比较准确描述材料的拉伸和剪切变形，针对柔性接头这种以剪切变形为主的结构，应选取剪切试验数据；当应变大于150％时，不同材料模型与试验数据的选用范围对计算结果具有明显影响。

Thermal fatigue on pistons induced by shaped high power laser. Part I: Experimental study of transient temperature field and temperature oscillation

Thermal fatigue behavior is one of the foremost considerations in the design and operation of diesel engines. It is found that thermal fatigue is closely related to the temperature field and temperature fluctuation in the structure. In this paper, spatially shaped high power laser was introduced to simulate thermal loadings on the piston. The incident Gaussian beam was transformed into concentric multi-circular beam of specific intensity distribution with the help of diffractive optical element (DOE), and the transient temperature fields in the piston similar to those under working conditions could be achieved by setting up appropriate loading cycles. Simulation tests for typical thermal loading conditions, i.e., thermal high cycle fatigue (HCF) and thermal shock (or thermal low cycle fatigue, LCF) were carried out. Several important parameters that affect the transient temperature fields and/or temperature oscillations, including controlling mode, intensity distribution of shaped laser, laser power, temporal profile of laser pulse, heating time and cooling time in one thermal cycle, etc., were investigated and discussed. The results show that as a novel method, the shaped high power laser can simulate thermal loadings on pistons efficiently, and it is helpful in the study of thermal fatigue behavior in pistons. (C) 2007 Elsevier Ltd. All rights reserved.

The scientific project of the small satellite of china

The efforts involved in developing a small satellite for scientific purposes in China in recent years are introduced in the present paper. The project is arranged on a case to case principle depending upon requirements and financial support. The space technology of a satellite and rockets, which have been developed over a relatively longer period in China, have been transferred to the scientific research of small satellites for improvement of the quality requirements. The surplus payloads of the rocket and satellite are used as the payloads of the small satellite and scientific experiments at a low cost. As an example, the project of balloon satellites for atmospheric research was successfully completed in 1991. The experience of the project management is of great benefit for further organization and arrangement of other projects. Opportunities exist for surplus payloads to be used in the future, and a small satellite for magnetospheric research will be launched in 1993.

火箭增程乘波外形导弹弹道特性研究

基于椭圆锥相交流场，采用非轴对称设计方法生成了一种带火箭增程的乘波外形高超声速导弹，并在给定攻角条件下对乘波外形导弹的弹道进行了仿真。仿真结果表明：导弹的飞行轨迹为波浪形；在满足热防护的条件下，给定乘波外形和初始滑翔速度的导弹存在一个较优的初始滑翔高度；导弹自带增程火箭的点火时间越早，其飞行距离越远。

模拟火箭引射混合特性的实验研究

专门设计了可用于研究箭基组合循环发动机（RBCC）在起动阶段（Ma= 0）所使用的引射火箭性能的实验装置。作为初步试验，研究了不同工况的引射热喷流（一次流）和被引射空气（二次流）之间混合的演 变、发展过程，找出不同来流条析下影响引射性能的主要参数，为最终探明引射火箭的最佳工作条件打下基础，同时根据试验结果提出了促进一、二次流混合的可行方案，便 于下一步深入研究。

应用于固体火箭发动机喷管出口羽流温度测量的光学辐射高温计

利用辐射光谱测量温度的原理,设计并制造了一种新型的非接触式光学辐射高温计.详细介绍该温度计的基本原理和标定方法,并将该温度计应用于火箭发动机喷管出口羽流的温度测量中,初步的实验结果和数值模拟结果相一致.

火箭剩余推进剂排放过程的分析与模拟

为了减少空间碎片的产生，星箭分离后，需要在轨排放火箭末级贮箱内的剩余推进剂．分析表明，排放条件下的推进剂射流进入太空后，立即失稳破碎为大量液滴；液滴在高真空环境下扩散，它们的表面不断有气体分子蒸发，逐渐在箭体周围形成了一个由液滴和蒸气分子组成的羽流场．采取Lagrange方法追踪该流场中每个液滴的运动轨迹以及表面蒸发冷凝过程，利用直接模拟Monte Carlo方法计算蒸气分子的运动和碰撞，然后通过微观量的统计平均获得感兴趣的宏观流场、箭体表面的压力和剪应力分布等．为了检验稀薄蒸气算法、模型和程序，模拟了真空水射流周围水蒸气羽流场，获得的径向Pitot压力分布与Fuchs和Legge的实验数据的符合．在此基础上，分别模拟了CZ-4B火箭末级剩余燃料偏二甲肼在不同排放方式下的三维稀薄蒸气与液滴羽流场．计算表明：原排放方式的扰动力矩相当大，超出了火箭姿控范围，新排放方式的扰动力矩很小，处于火箭姿控范围之内．这些预测得到了飞行遥测数据的支持．

Heat Transfer of Aviation Kerosene at Supercritical Conditions

The heat transfer characteristics of China no. 3 kerosene were investigated experimentally and analytically under conditions relevant to a regenerative cooling system for scramjet applications. A test facility developed for the present study can handle kerosene in a temperature range of 300-1000 K, a pressure range of 2.6-5 MPa, and a mass How rate range of 10-100 g/s. In addition, the test section was uniquely designed such that both the wall temperature and the bulk fuel temperature were measured at the same location along the flowpath. The measured temperature distributions were then used to analytically deduce the local heat transfer characteristics. A 10-component kerosene surrogate was proposed and employed to calculate the fuel thermodynamic and transport properties that were required in the heat transfer analysis. Results revealed drastic changes in the fuel flow properties and heat transfer characteristics when kerosene approached its critical state. Convective heat transfer enhancement was also found as kerosene became supercritical. The heat transfer correlation in the relatively low-fuel-temperature region yielded a similar result to other commonly used jet fuels, such as JP-7 and JP-8, at compressed liquid states. In the high-fuel-temperature region, near and beyond the critical temperature, heat transfer enhancement was observed; hence, the associated correlation showed a more significant Reynolds number dependency.

固体火箭发动机喷管气固两相流动的数值模拟

对颗粒相采用颗粒轨道模型,气相求解可压缩N-S方程组,计算方法采用显式Runge-Kutta时间推进法与有总变差衰减(TVD)性质的高精度MUSCL-Roe格式;自主开发了曲线坐标系下二维轴对称可压缩N-S方程组的解算器Solve2D,研究了固体火箭发动机喷管中颗粒相对流场的影响以及不同尺寸颗粒运动规律.结果表明:颗粒相对流场的影响主要表现在喷管喉部以及扩张段,和单相流场相比,沿轴线马赫数减小,且颗粒尺寸越小减少得越多;沿轴线气相温度升高,且颗粒尺寸越小温度升高越多;颗粒尺寸越小,无粒子区越小;颗粒越大与收缩段壁面碰撞越剧烈,无粒子区越大.

Design and Operation of A 5.5 MWe Biomass Integrated Gasification Combined Cycle Demonstration Plant

The design and operation of a 5.5 MWe biomass integrated gasification combined cycle (IGCC) demonstration plant, which is located in Xinghua, Jiangsu Province of China, are introduced. It is the largest complete biomass gasification power plant that uses rice husk and other agricultural wastes as fuel in Asia. It mainly consists of a 20 MWt atmospheric circulating fluidized-bed gasifier, a gas-purifying system, 10 sets of 450 kW(e) gas engines, a waste heat boiler, a 1.5 MWe steam turbine, a wastewater treatment system, etc. The demonstration plant has been operating since the end of 2005, and its overall efficiency reaches 26-28%. Its capital cost is less than 1200 USD/kW, and its running cost is about 0.079 USD/kWh based on the biomass price of 35.7 USD/ton. There is a 20% increment on capital cost and 35% decrease on the fuel consumption compared to that of a 1 MW system without a combined cycle. Because only part of the project has been performed, many of the tests still remain and, accordingly, must be reported at a later opportunity.

Upgrading bio-oil over different solid catalysts

Solid acid 40SiO(2)/TiO2-SO42- and solid base 30K(2)CO(3)/Al2O3-NaOH were prepared and compared with catalytic esterification activity according to the model reaction. Upgrading bio-oil by solid acid and solid base catalysts in the conditioned experiment was investigated, in which dynamic viscosities of bio-oil was lowered markedly, although 8 months of aging did not show much viscosity to improve its fluidity and enhance its stability positively. Even the dehydration by 3A molecular sieve still kept the fluidity well. The density of upgraded bio-oil was reduced from 1.24 to 0.96 kg/m(3), and the gross calorific value increased by 50.7 and 51.8%, respectively. The acidity of upgraded bio-oil was alleviated by the solid base catalyst but intensified by the solid acid catalyst for its strong acidification. The results of gas chromatography-mass spectrometry analysis showed that the ester reaction in the bio-oil was promoted by both solid acid and solid base catalysts and that the solid acid catalyst converted volatile and nonvolatile organic acids into esters and raised their amount by 20-fold. Besides the catalytic esterification, the solid acid catalyst carried out the carbonyl addition of alcohol to acetals. Some components of bio-oil undertook the isomerization over the solid base catalyst.