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在推进剂燃烧的建模上,传统的热力计算方法一般基于总焓守恒求解定压绝热燃烧温度和平衡组分,不能考虑壁面传热;在燃气流动的建模上,通常采用的冻结流模型认为本地的组分及热物理性质与燃烧室瞬时一致,忽略了这些参数因来流气体与本网格滞留气体掺混带来的随时间的缓变效应。提出了一种新颖的可以考虑壁面传热的基于总能量守恒的化学平衡流计算方法,运用Fortran2008语言,采用面向对象编程方法建立了化学平衡流燃气发生器管道的模块化仿真模型,并将该模型应用到一个包含42个组件的涡轮试验台气路系统的建模与仿真中。与早期模型仿真结果及试验数据的对比发现,新模型的仿真结果有一定改进,更加接近试验数据。 相似文献
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针对X牌号环氧胶粘剂在试验过程中出现拉伸剪切强度不合格的现象,通过大量的试验查找原因,最终确定了影响胶粘剂拉伸剪切强度的因素。同时,提高了对试片的制备、处理、粘接、固化的理论认识和实际操作水平。 相似文献
55.
非平衡电弧加热射流光谱学诊断方法:第一部分 氩射流 总被引:1,自引:1,他引:0
从一般意义上给出了非平衡电弧加热射流光谱学诊断方法和结果。表明非平衡亚声速电弧加热射流中心是LTE的,沿径向形成一非平衡囊兜,囊兜的最深位置约在1/2射流半径处。 相似文献
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In order to improve the deposition rate and microstructure of pyrocarbon, nickel was introduced by electroplating on carbon fibers and used as a catalyst during the deposition of pyrocarbon at 1000 C using methane as a precursor gas. The distribution of nickel catalyst and the microstructure of pyrocarbon were characterized by scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS), X-ray diffraction(XRD), and Raman micro-spectrometry. Results show that nano-sized nickel particles could be well distributed on carbon fibers and the pyrocarbon deposited catalytically had a smaller d002 value and a higher graphitization degree compared with that without catalyst. In addition, the deposition rate of pyrocarbon in each hour was measured.The deposition rate of pyrocarbon in the first hour was more than 10 times when carbon cloth substrates were doped with nickel catalysts as compared to the pure carbon cloths. The pyrocarbon gained by rapid deposition may include two parts, which are generation directly on the nickel catalyst and formation with the carbon nanofibers as crystal nucleus. 相似文献
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通过冻融和化学侵蚀试验,研究了NW-056A机场道面除冰液对道面水混混凝土耐久性的影响以及在道面除冰液环境下两种新型混凝土保护剂的防护效果。结果表明:①混凝土在道面除冰液中冻融后表面无明显剥落现象,相对动弹模损失率比在水中小很多,道面除冰液延缓了混凝土的冻融破坏:②混凝土在道面除冰液常温浸泡下表面无剥蚀现象,但强度比在水中降低很多,因此存在化学腐蚀.且主要表现为对混凝土内部结构的缓慢损伤;(④两种新型混凝土保护剂均对预防混凝土的冻融破坏以及除冰液环境下的腐蚀破坏起到一定作用,涂刷混凝土保护剂是提高混凝土道面耐久性的有效方法。 相似文献
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FINITE DIFFERENCE MODEL FOR SIMULATION OF DENSIFYING CARBON-CARBON COMPOSITES BY CHEMICAL VAPOR INFILTRATIONP ROCESSES 总被引:1,自引:0,他引:1
NomenclaturesA0—coeficientoftheArheniusequationC(n)—hydrocarbonconcentrationinunit(n)(mol/cm3)C0—hydrocarbonconcentrationatex... 相似文献
60.
S.I. Bartsev V.V. Mezhevikin 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008
Searching for extraterrestrial life attracts more and more attention. However this searching hardly can be effective without sufficiently universal concept of life origin, which incidentally tackles a problem of origin of life on the Earth. A concept of initial stages of life origin is stated in the paper. The concept eliminates key difficulties in the problem of life origin, and allows experimental verification of it. According to the concept the predecessor of living beings has to be sufficiently simple to provide non-zero probability of self-assembling during short (in geological or cosmic scale) time. In addition the predecessor has to be capable of autocatalysis, and further complication (evolution). A possible scenario of initial stage of life origin, which can be realized both on other planets, and inside experimental facility is considered. In the scope of the scenario a theoretical model of multivariate oligomeric autocatalyst is presented. Results of computer simulation of two versions of oligomeric autocatalytic reactions are presented. It is shown that the contribution of monomer activation reaction is essential, and in some cases autocatalysis in polymerizing reaction can be achieved without catalyzing proper monomer binding reaction. 相似文献