NEPE推进剂用中性聚合物键合剂的分子设计

中性聚合物键合剂(NPBA)是美国Kim C.S.发明的一种新助剂。这种键合剂可显著提高NEPE推进剂的力学性能。本文根据Kim C.S.发表的专利和论文,介绍了降温相分离沉积包覆的原理,归纳提出了NPBA的分子设计方法,并且举例说明。     

IR radiation characteristics of rocket exhaust plumes under varying motor operating conditions

The infrared(IR) irradiance signature from rocket motor exhaust plumes is closely related to motor type,propellant composition,burn time,rocket geometry,chamber parameters and flight conditions.In this paper,an infrared signature analysis tool(IRSAT) was developed to understand the spectral characteristics of exhaust plumes in detail.Through a finite volume technique,flow field properties were obtained through the solution of axisymmetric Navier-Stokes equations with the Reynolds-averaged approach.A refined 13-species,30-reaction chemistry scheme was used for combustion effects and a k-e-Rtturbulence model for entrainment effects.Using flowfield properties as input data,the spectrum was integrated with a line of sight(LOS) method based on a single line group(SLG) model with Curtis-Godson approximation.The model correctly predicted spectral distribution in the wavelengths of 1.50–5.50 lm and had good agreement for its location with imaging spectrometer data.The IRSAT was then applied to discuss the effects of three operating conditions on IR signatures:(a) afterburning;(b) chamber pressure from ignition to cutoff;and(c) minor changes in the ratio of hydroxyl-terminated polybutadiene(HTPB) binder to ammonium perchlorate(AP) oxidizer in propellant.Results show that afterburning effects can increase the size and shape of radiance images with enhancement of radiation intensity up to 40%.Also,the total IR irradiance in different bands can be characterized by a non-dimensional chamber pressure trace in which the maximum discrepancy is less than 13% during ignition and engine cutoff.An increase of chamber pressure can lead to more distinct diamonds,whose distance intervals are extended,and the position of the first diamond moving backwards.In addition,an increase in HTPB/AP causes a significant jump in spectral intensity.The incremental rates of radiance intensity integrated in each band are linear with the increase of HTPB,and the growth rates of radiance intensities in some bands reach up to 50% as HTPB weight increases by 3%.     

固体发动机装药CAD

基于计算机图形处理直接获得燃面几何数据,发展了一种装药设计新方法,可以进行装药燃面、质量及惯性随肉厚变化的计算,为一维内弹道计算及流场计算提供更为详尽的数据,还能进行动态燃面推移,使设计者直观地判断其设计的合理性。     

变混合比及三组元发动机用于单级入轨

研究了氢氧变混合比以及三组元发动机在单级入轨飞行器上的应用,包括了普通固定膨胀比发动机和塞式发动机。依据最优弹道计算,分别讨论了燃料混合比控制方案以及组元分配方案。分析了燃料混合比连续可变时的飞行器性能,克服了以往分析中只设定两种混合比及分析过于理想化的问题。     

超高燃速推进剂的燃速催化剂研制

合成了三种含铜或／和铅的有机金属化合物燃速催化剂ＰＡＣ、ＰＡＰＣ和ＰＡＰ,它们对ＡＰ微孔固体推进剂燃烧有显著催化作用,其中ＰＡＣ和ＰＡＰＣ能使该推进剂在５ＭＰａ～２５ＭＰａ压力范围内达到１ｍ／ｓ以上的超高燃速,燃烧较为平稳。通过热分析和实测燃速等探讨了催化剂对推进剂催化燃烧的主要作用阶段。     

有机结合 PVT 和 BK 法以降低测量卫星液体推进剂的不确定度

提出了一种ＰＶＴ和ＢＫ有机结合以降低卫星液体推进剂测量不确定度的新方法,通过分析说明了当应用高精度高分辨压传感器测量压力时,卫星寿命末期推进剂测量不确定度可降低到贮箱总体积的２％以下。     

端羟基聚丁二烯预聚物的流动特性研究

研究了ＨＴＰＢ预聚物的流动粘度。结果表明：粘度的对数值随温度变化关系中存在着一个临界温度（Ｔｃ）,低于该临界温度时粘度变化较大,而高于该临界温度时则粘度变化较慢。临界温度随ＨＴＰＢ预聚物相对分子质量增加而升高,随增塑剂ＤＥＨＳ含量的增加而下降。     

ADN 及其混合物燃烧性能的理论计算

分析了新型含能材料二硝酰胺铵（ＡＤＮ）的热分解特性和燃烧特性,提出ＡＤＮ燃烧初期热分解反应的假说,建立了由化学结构特征计算ＡＤＮ及其混合物燃速公式,并计算了ＡＤＮ和配比不同的ＡＤＮ混合物的燃速特征。计算结果与实测值十分一致。从化学结构和化学反应的层次分析了ＡＤＮ单质燃烧出现平台燃烧现象的原因,认为ＡＤＮ热分解过程中,中间产物ＮＨ４ＮＯ３的形成和消失在平台（麦撒）燃烧中起着关键作用。预测了ＡＤＮ提高固体推进剂燃速和降低燃速压力指数的趋势。     

固体推进剂燃烧微观诊断技术述评

对近年来用于固体推进剂燃烧的微观诊断技术的原理、结果进行了综述,分析了用扫描电镜、热分析、Ｘ－ｒａｙ电子能谱仪、红外傅里叶光谱技术,微热电偶测温技术,ＬＩＦ,ＣＡＲＳ测试固体推进剂燃烧现象的结果,提出了存在的问题和努力的方向。     

燃烧室压力对空气雾化喷嘴雾化性能的影响

对某发动机上的空气雾化喷嘴进行了实验研究, 以探讨燃烧室压力对空气雾化喷嘴性能的影响。实践证实本文研究结果对高压下空气雾化喷嘴的设计做了有益的探索。