铝盐絮凝剂絮凝性能和机理研究

系统研究了无机低分子铝盐、无机高分子铝盐以及无机铝盐和有机高分子絮凝剂ＰＡＭ复配使用处理高浊度原水的絮凝性能和机理，测定了电导率和粘度，并用显微摄影拍摄了絮凝过程程不同阶段矾花大小的变化。为管式絮凝器的研制和铝盐絮凝剂的选择提供了理论依据。     

固体润滑技术在空间机械中的应用

对空间机械润滑的特殊性作了简要的分析,评述了各种固体润滑材料在空间环境中的摩擦磨损性能,介绍了各种固体润滑膜的制备工艺及其在空间机械中的应用情况,并指出了有待进一步研究的问题。     

液路耦联多发动机系统开关机动态特性研究

通过对液路耦联的多发动机系统动态特性仿真研究表明：多发动机开关机时水击对相互间性能影响比较大,若设计不合理,有可能导致异常关机。给出的动力学模型可以用于空间飞行器耦联多发动机系统的结构及工作模式设计和解释一些发动机试车现象。     

航天器推进系统管路充填过程动态特性(1)理论模型与仿真结果

研究了航天器推进系统管路充填过程动态模型与计算方法。以一维管道瞬变流理论为基础 ,采用瞬变管流湍流频率相关摩擦损失模型计算管壁摩擦流阻 ,构造了管路分支流阻计算模型 ,考虑了液流撞壁后的蒸汽泡团释出与崩溃现象。数值计算采用特征线方法 ,仿真结果表明计算模型较好地描述了充填过程中的水击和管流振荡现象     

均匀磁场中铁磁流体润滑的平板滑块的性能

计算结果表明,铁磁流体润滑的平板滑块的性能与牛顿流体或Bingham塑料润滑的平板的性能显著不同.屈服应力引起粘附核的发生,并且增加滑块的承载能力.在低速润滑中,高磁场强度对承载能力是有好处的,因为它可以提高铁磁流体的粘度和在润滑膜中引起粘附核.当出现粘附核时,铁磁流体润滑的平板滑块的最佳膜厚比的值大于2.2,并随外磁场强度增加而增大.在高速润滑中,可能没有粘附核出现,在此情况下,为了得到最大承载能力而采用膜厚比的值为2.2是可取的.在高磁场强度或高剪切速率下,铁磁流体润滑的平板滑块的摩擦系数增大.      

双线圈高速开关阀的水击特性验证

高速开关阀是航天领域动力系统的关键元件,需要具备高频响和高可靠性。然而,高速开关阀的开关特性会使系统产生水击现象,降低系统的可靠性,尤其是在高速开关阀高频切换过程中会产生更多的水击压力波,致使系统中的水击变得更加复杂。因此,采用仿真和实验相结合的方法对不同频率下水击压力脉动的变化进行分析,最终通过对数据时域和频域的分析,发现了高速开关阀的水击压力脉动规律,研究结果可在航天动力系统中应用。     

高速发动机油膜惯性对活塞裙润滑影响

利用一种新的迭代算法 ,分析了高速发动机油膜惯性对活塞裙润滑特性的影响 .该迭代方法是利用有限元法和差分法交替求解Navier Stocks方程和雷诺方程 ,据此导出了适用于高速发动机活塞裙的润滑计算的混和润滑雷诺模型 .新的模型借助惯性系数 ,引入了油膜惯性项 ;同时给出求解含有油膜惯性项的迭代步骤和有限元表达式。计算结果表明 :随着惯性系数和活塞裙的长径比的不同 ,油膜惯性会对油膜的摩擦力、压力和承载力产生不同的影响 ,这种影响对承载力尤为明显 .该润滑模型也可用于中、低速发动机的活塞裙润滑计算以及不计入惯性项 (惯性系数置为零 )的某些润滑问题求解 .     

TBCC发动机涡轮进气道喷水冷却特性数值研究

对涡轮基组合循环(Turbine Based Combined Cycle, TBCC)发动机涡轮进气道进行喷水冷却是解决TBCC发动机推力不连续问题的有效方式之一。本文基于实际流场条件选取某型TBCC发动机涡轮进气道结构,对进气道内喷水冷却特性进行了数值仿真,研究飞行器不同工况下水滴的蒸发特性及喷水对来流高温空气的预冷效果。结果表明,来流空气温度降幅随水气比提高而增大,最高温降可达152.4K。水气比提高后水滴蒸发率逐渐降低,但蒸发总量仍会继续上升。相同水气比条件下,飞行马赫数越高,喷水冷却效果越明显。在Ma3.5飞行速度和水气比0.03条件下有最高蒸发率,达83.05%。喷水冷却有效扩展了涡轮模态飞行马赫数,最高能使飞行速度提升至Ma2.84,即喷水冷却扩展了TBCC从涡轮模态向超燃冲压模态转换的衔接速域。     

海流对出水空泡演化过程影响机理数值研究

采用数值仿真手段,重点针对海流对空泡演化过程的影响开展研究,形成考虑海流影响的空泡多相流理论与数值计算方法,分析了海流流向及流速影响,获得了海流对空泡发展演化的作用机制及对航行体流体动力特征的影响规律。研究结果表明:航向海流对溃灭阶段的空泡形态变化影响较为明显,不同海流工况下,泡内水、气分布有所不同,高压产生次序及溃灭过程的流动结构变化也因此不同。横向海流作用下的空泡形态差别不大,受到合成来流方向发生偏转的影响,迎流面向横向来流方向偏斜,造成空泡形状不对称。     

Application of satellite observations to study the changes of hypoxic conditions in near-bottom water in the western part of Peter the Great Bay (the Sea of Japan)

In this paper we explore the possibilities of applying satellite ocean colour (OC) observations and SST to study the changes in the conditions of hypoxia in the near-bottom water in the western part of Peter the Great Bay. Near-bottom water hypoxia occurs in water bodies with increased organic matter influx when the dissolved oxygen (DO) consumed at its oxidation is not restored. Consumption of most DO is usually attributed to the oxidation of organic matter formed as a result of increased algae growth during water eutrophication. Satellite data on indicators of phytoplankton (chlorophyll-a concentration (Chl) and fluorescence (FLH)) allow to analyze the spatial-temporal changes of this substation. Coloured dissolved organic matter (CDOM), non-algal particles (NAP) influence on satellite Chl estimates and also on near-bottom water hypoxia formation. This study analyzes daily, seasonal, and inter-annual changes in the distributions of indicators (Chl, FLH, the coefficients of light absorption by coloured detrital matter (a_CDM) and light backscattering by suspended particles (b_bp)), based on the instant satellite OC data from MODIS-Aqua. Data on the Chl, the sea surface temperature (SST) from the MODIS-Aqua, the precipitation from the TRMM satellite and the hydrometeorological stations (HMSs), the wind speed and direction from HMS “Vladivostok” are used to study the influence of hydrometeorological conditions on the Chl values. These distributions were compared with the literary information based on field observations of the hypoxia cases in the same area and with the changes in the vertical DO, Chl, temperature, salinity distribution obtained by coastal expeditions in October-November 2010 and February-March 2011. Significant interrelations within 95% confidence level between the satellite Chl, FLH values calculated at the MUMM atmospheric correction and in situ Chl values obtained in the autumn of 2010 were reached separately for the cases with winds of northern and southern directions with the correlation coefficients of 0.71, 0.48 and 0.49, 0.71, respectively. Significant dependences of Chl on SST and Chl on wind speed explained by the influence of continental runoff and water ventilation were obtained. Therefore, the changes of Chl reflect the changes of hypoxic conditions in the near-bottom water. In Amursky Bay the onset of hypoxia was at the Chl and SST values equal to 4 mg m^?3 and 13 °C (↑ – at increasing SST); near Furugelm Island it was at 1.6 mg m^?3 and 25 °C (↑), 1 mg m^?3 and 21 °C (↓). The difference in the Chl values was reflected in the hypoxia onset timings that were the beginning of June (2011), August (2013), and September (2014), respectively. The water flow from the eastern coast of Amursky Bay in early August of 2013 recorded from the OC and SST satellite imagers appeared in an additional hypoxic zone. Decreased OC characteristics in the runoff of the Razdolnaya River in August-September of 2014 were a sign of hypoxia at its mouth. Near Furugelm Island the hypoxia destruction (increase in the DO level from 1 to 4.5 ml L^?1) was observed at the Chl of 0.9 mg m^?3 and SST = 18 °C (↓). At the autumn maximum of Chl equal to 1.7 mg m^?3 and SST = 4 °C (↓) in mid-November the DO level here increased to 8 ml L^?1. In Amursky Bay, short-term destructions/weakening of hypoxia manifested themselves in sharp increases of Chl. At that, the ratio between the Chl value and the approximation level was equal to 2 and higher for SST equal to 22–25 °C (↑), to 0.9 and higher for SST equal to 5–13 °C (↓). With the water stratification destruction in temperature and the noticeable weakening of the stratification in salinity (mid-November), the hypoxia destructed (the DO level increased from 2 to 6 ml L^?1). In this case, Chl and SST were about 3 mg m^?3 and 5 °C (↓).