Characteristic Research on Evaporated Explosive Film

The evaporation source of evaporated explosive was designed and improved based on the inherent specialties of explosive. The compatibility of explosives and addition agent with evaporation vessels was analyzed. The influence of substrate temperature on explosive was analyzed, the control method of substrate temperature was suggested. The influences of evaporation rate on formation of explosive film and mixed explosive film were confirmed. Optimum evaporation rate for evaporation explosive and the better method for evaporating mixed explosive were presented. The necessary characteristics of the evaporated explosive film were obtained by the research of the differences between the evaporated explosive and other materials.     

Transient measurement of temperature oscillation during noisy film boiling in superfluid helium Ⅱ

Noisy film boiling, which is characterized by a loud noise and severe mechanical vibration, is a particular phenomenon of superfluid helium II (He II). Experiments have been conducted under various thermal conditions by varying the heating time th and the heat flux q, and the temperature oscillation during noisy film boiling is measured by the superconductor temperature sensors in order to understand the physical mechanism of noisy film boiling.     

Transient measurement of temperature oscillation during noisy film boiling in superfluid helium II

Noisy film boiling, which is characterized by a loud noise and severe mechanical vibration, is a particular phenomenon of superfluid helium II (He II). Experiments have been conducted under various thermal conditions by varying the heating timet _h and the heat fluxq, and the temperature oscillation during noisy film boiling is measured by the superconductor temperature sensors in order to understand the physical mechanism of noisy film boiling.     

Study on Property of Desensitized Explosive Film

The mechanical sensitivity, the critical thickness of detonation wave propagation and detonation velocity of desensitized PETN film were studied by experiments. The relationship between the mass of desensitizer paraffin wax and the friction sensitivity of desensitized PETN film was tested. According to the microstructure of film, the function of desensitizer was explained. It was proved that the explosive film could make explosive element micromation and kept its inherence properties by the result of testing the propagating critical dimension of the desensitized PETN film detonation wave. The explosive velocity of confined desensitized PETN film was tested by the multiplex optical fibre.     

表面芯吸性对淬火过程中沸腾传热特性的影响

研究表面芯吸性对淬火过程中的冷却速率和沸腾传热特性的影响.采用质量分数约为50%的氢氟酸溶液对不锈钢球表面进行化学腐蚀,在恒温50℃时通过改变腐蚀时间得到具有不同芯吸性的试样并对表面芯吸量和初始芯吸通量进行定量表征.在常压下的饱和水中对所制备的芯吸表面进行可视化淬火实验.结果表明,原始不锈钢表面不具有芯吸性,随着腐蚀时间的增加表面芯吸能力也逐渐增强.经过腐蚀3 min之后,表面芯吸通量达到20 μL/（mm²·s）.该芯吸表面使淬火冷却时间相较于原始表面缩短约80%,临界热流密度提高了约84%.构建表面芯吸性可以有效地增大固液接触面积并加剧表面汽膜波动,抑制了稳定膜态沸腾的出现,强化了过渡态沸腾传热.     

瞬态情况下的射流冲击沸腾传热特性的实验研究

研究了在膜态沸腾、过渡沸腾和临界热流密度处的传热特性。采用淬冷的方式在射流速度为2.5m/s以上,初始壁温约为700℃的情况下,得到了完整的沸腾曲线。从实验结果可以看出,沸腾曲线的位置向右偏移且形状发生了变化,q_(max)降低了一个数量级。     

平阴尿塔塔体爆炸能量分析与计算

通过计算平阴尿塔爆炸时上部塔段抛射功、中部塔段平射功和筒体撕裂功,得到了尿塔爆炸时自身消耗的总能量.通过与塔内物料所能产生的膨胀或沸腾总功以及外界消耗功相比较,得出了该塔充分具备了爆炸破坏的能量条件的结论,为该塔进行正确的失效分析提供了依据.     

低温重力热管传热性能的理论与实验研究

为给重力热管在低温区的应用提供理论依据,以液氮作为工质对其稳态传热特性进行了实验研究.分别对冷凝段、蒸发段液膜和液池进行分析,建立了综合的数学模型.根据质量和能量守恒方程迭代计算得到了液池高度和液膜沿管长的分布.在液池模型中,通过假设空泡系数的分布,基于其他实验研究的结论提出了自然对流与核态沸腾换热面积公式.当工质液体体积与重力热管总体积的比值为13.5%和15.2%时,计算值与实验值吻合较好.理论和实验研究结果均表明,在蒸发段内液膜和液池的位置对蒸发段壁温的分布有较大的影响.     

高浓双氧水预热器温度与系统压力关系研究

通过计算（５０％，ｗｔ）双氧水在不同压力下溶液的沸点，找出预热器温度与系统压力的关系，为实际生产过程提供了可靠理论依据。     

窄隙流道自然对流沸腾流动不稳定性实验研究

以水为工质，分别在过冷和饱和条件下对竖直窄环隙流道进行了自然对流沸腾流动不稳定性实验，观测到了窄隙流道饱和沸腾时所特有的蒸干型流动不稳定性．分析了流道进出口过冷度、加热负荷、温度分布、汽化核心、几何尺寸等因素对低干度流动不稳定性的影响，划分了饱和沸腾时各类流动不稳定性的发生区域，并给出了用于预计不稳定性界限值的经验公式．     

垂直管内流动相变强化传热的研究

以异丙醇 -水溶液为研究物系 ,引入空气对垂直管内流动相变强化传热进行了实验研究。分析了气体对平均传热膜系数的影响 ,并发现传热膜系数随异种气体的引入量和液速的增加而增加 ,随浓度的增加而下降 ;壁面过热度随着液速和异种气速的增加而降低 ;并在此基础上获得流动相变强化传热的关联式。     

Numerical study on convective heat transfer of supercritical CO2 in vertically upward and downward tubes

The experimental measurement of supercritical pressure carbon dioxide(sCO_2) heat transfer in vertical downward flow was performed in a circular tube with inner diameter of 10 mm. Then, a three-dimensional numerical investigation of sCO_2 heat transfer in upward and downward flows was performed in a vertical heated circular tube. The influence of heat flux, mass flux,and operating pressure on heat transfer under different flow directions were discussed. According to the "pseudo-phase transition" viewpoint to supercritical fluids, the analogy to the subcritical inverted-annular film boiling model, the physical model to sCO_2 heat transfer was established, where fluid region at the cross-section of circular tube was divided into gas-like region covering heated wall and core liquid-like phase region. Then, the thermal resistance mechanism which comprehensively reflected the effect of multiple factors including the thickness of the gas-like film or liquid-like region, fluid properties and turbulence on heat diffusion was proposed. Surprisingly, thermal resistance variation in upward flow is well identical with that of wall temperature and heat transfer deterioration is predicted successfully. In addition, compared with thermal resistance in the core liquid-like region, gas-like film formation is determined to be the primary factor affecting heat transfer behavior. Results also show that total thermal resistance in upward flow is always larger than that in downward flow. The investigation can provide valuable guide to design and optimize sCO_2 heaters.     

喷涂多孔表面沸腾传热实验研究

对喷涂多孔表面沸腾传热进行了实验研究,喷涂多孔表面有三种厚度,采用蒸馏水、乙醇和R—113作实验工质,实验在当地大气压下进行．实验结果表明：喷涂多孔表面上产生沸腾的起始过热度低,传热系数比光滑表面高2—5倍．喷涂多孔表面沸腾临界热流也比光表面高,可以在比较宽的热流范围内强化沸腾换热．实验还表明：喷涂多孔表面也具有沸腾滞后现象,但是,滞后过热度较小．喷涂技术不仅具有设备简单、操作方便、费用低等优点,还具有能够适应不同基体表面形状的特殊优点．因此,喷涂表面是热管技术和蒸发器强化沸腾传热的一种有效方法．     

高粘液体两相流型观察及关联

在透明镀膜玻璃管中，进行高粘假塑性流体流动沸腾传热实验研究。观察到一种新的流型：闪蒸沸腾。基于５３５个流型数据，建立了流型关联式。     

白腐工程菌处理TNT炸药废水的研究

采用单因素寻优及正交方法研究了时间、温度、pH值、木质素用量等因素对白腐菌降解TNT炸药废水的影响。结果表明,当反应时间为48h,生化温度为℃,pH值为5,木质素投加量为n3时,TNT废水的COD去除率为99％。本文还对白腐菌降解TNT废水的动力学过程进行了探讨。     

棘轮型超紧凑燃烧室全覆盖气膜冷却性能

针对新一代棘轮型超紧凑燃烧室壁面的高温问题,对全覆盖气膜冷却的方式进行了研究。在对KJ-66微型涡喷发动机实验与模拟的基础上,将原燃烧室替换为缩放优化后的棘轮型超紧凑燃烧室。在实际燃烧工况下,对突扩段斜坡和二次补燃区内环上的高温壁面进行全覆盖冷却研究,比较了不同排布方式、孔倾角和扩张型气膜孔对气膜冷却效果的影响。结果表明:突扩段斜坡上圆柱型气膜孔的气膜覆盖性不理想,综合气膜冷却效果欠佳,并且不同排布方式与孔倾角对气膜冷却效果的影响不大;扩张型气膜孔对斜坡的气膜贴壁性和冷却效果都有很大的改善,在45°孔倾角,出口直径0.6 mm的扩张孔模型中,由吹离高温火焰面与气膜叠加覆盖产生的综合冷却效果达到最优;在主流高离心力场的影响下,吹风比较大时二次补燃区下游也能获得较好的气膜贴壁效果;排布方式对二次补燃区气膜冷却效果的影响比孔倾角更明显。在实际燃烧工况下全覆盖气膜冷却对棘轮型超紧凑燃烧室壁面有很好的冷却作用,扩张型气膜孔能有效改善气膜冷却效果。     

时间-温度迭加原理在炸药分解研究中的应用

针对炸药分解研究所面临的困难,提出了运用时间--温度迭加原理将常温下炸药分解研究转化为较高温度下的研究,并结合某炸药分解试验数据,计算得到该炸药在20℃条件下贮存20年与48.2℃条件下贮存1年分解情况基本相同,最后经炸药热分解动力学计算验证该原理的可用性.     

泵抽空状态下机械密封端面状况实验研究

通过机械密封在泵抽空状态下的端面运行状况实验，基于流体膜的相变理论，讨论了机技密封在泵抽空状态下端面开启可能性，并分析了机械密封在抽空瞬时因工况改变可能造成的失效，提出了机械密封运行的稳定工作条件，对机械密封在特殊工况下的设计及使用、提高机械密封的抗抽空能力提出了参考意见．     

多效蒸发海水淡化系统模拟计算与优化

以9效竖管降膜多效蒸发海水淡化系统为例,分别应用等温差分配法和等面积分配法对多效蒸发海水淡化系统进行了模拟计算,计算过程中考虑了海水沸点升高的影响。计算结果表明,在相同的淡水产量前提下,等温差分配法和等面积分配法的模拟计算结果相差不大,等温差分配得到的蒸发器总面积要比等面积分配得到的蒸发器总面积略小,等面积分配所需的加热生蒸汽量比等温差分配所需加热生蒸汽量略少。同时,以系统总传热损失最小为优化目标对多效蒸发海水淡化系统进行了优化计算,并将优化设计结果与等面积分配法的计算结果进行了比较,结果表明,优化计算结果比等面积分配计算结果节省传热面积20.3%,节省加热生蒸汽量3.3%,可以有效降低海水淡化淡水成本。     

Film-induced stress enhancing stress corrosion cracking of austenitic stainless steel

A constant deflection device designed for use within a transmission electron microscopy (TEM) was used to investigate the change in dislocation configuration ahead of a crack tip during stress corrosion cracking (SCO of type 310 austenitic stainless steel in a boiling MgCI2 solution, and the initiation process of stress corrosion microcrack. Results showed that corrosion process during SCC enhanced dislocation emission, multiplication and motion. Microcracks of SCC were initiated when the corrosion-enhanced dislocation emission and motion reached critical state.A passive film formed during corrosion of austenitic stainless steel in the boiling MgCI2 solution generated a tensile stress. During SCC, the additive tensile stress generated at the metal/passive film interface helps enhance dislocation emission and motion.