含硼溶液黏/密度及比定压热容实验研究

采用振动管法、毛细管法以及流动型量热法分别测量了温度在10-90℃内、压力为0.1 MPa时,含硼质量浓度分别为5000 mg/L和1300 mg/L时含硼溶液的液相密度、黏度、比定压热容,获得了高精度的实验数据。经过分析,密度、黏度和比定压热容的测量扩展不确定度分别小于1.5%,3%和3%(k=2)。实验结果表明:随着溶液中含硼量的增加,溶液的密度和黏度是增加的,而溶液的比定压热容降低。此外,文中还将获得的密度、黏度和比定压热容实验数据拟合成了温度的多项式,其相关系数R均超过0.99,可以满足工程需求。

碳酸二甲酯与烷烃混合物的临界性质

本文基于低停留时间流动法建立了一套临界性质实验测量系统,该系统温度和压力的测量不确定度分别小于0.20 K和5.2 kPa。首次测量了碳酸二甲酯与正己烷、正庚烷、正辛烷、正壬烷和正癸烷五种烷烃的二元混合体系的临界性质,结果表明:各混合体系的临界温度随碳酸二甲酯混合比例的增加呈抛物线变化,临界压力随混合体系中临界压力较大物质混合比例的增加而增大。运用Redlich-Kister方程对以上混合体系临界性质进行了关联,临界温度和临界压力的平均绝对偏差分别小于0.04%和0.25%.

聚环氧乙烷在水和叔丁醇溶液中分子构型变化的研究

在聚合物溶液中,聚合物单体和溶剂分子之间的相互作用会影响聚合物高分子的尺寸和结构。本文使用动态光散射实验系统研究了聚环氧乙烷在水+TBA二元混合溶液中的分子尺寸变化,实验结果表明聚环氧乙烷分子会呈现出收缩-膨胀的奇异性构型变化。本文也系统分析了产生该现象的原因,依次分析了在二元混合溶液中可能对聚合物分子尺寸产生影响三个原因:溶剂非理想性影响(Shultz-Flory理论)、临界涨落影响以及水+醇溶液所呈现出来的奇异性性质。结合这三个因素,本文较好地解释了实验所观测到的奇异现象。

利用乙醇音速计算其它热力学性质

光散射法音速测量的适用温度范围较广,且有时高温比定压热容相对于密度而言更容易获得实验数据。基于此,提出了一个由较高温度比定压热容推算得到较高温度密度的迭代算法。以乙醇为例,利用高温热力学性质推算模型得到298.15~418.15 K、1.0 MPa下乙醇的密度,与Schroeder状态方程的计算结果进行对比,二者的平均绝对相对偏差为0.0119%,最大偏差为0.0298%。此外,沿1.0 MPa等压线测量了298.45~423.02 K温度范围内乙醇的液相音速,测量的拓展相对不确定度为0.9%(置信因子取2)。与Schroeder状态方程相比,298.15~418.15 K.1.0~9.0 MPa下乙醇密度和比定压热容计算值的平均相对偏差分别为0.0072%和0.0067%,最大偏差分别为0.0298%和0.0290%。可以看出,高温热力学性质推算模型的密度计算精度与实验测量精度相当。

Theoretical investigation on water/metal fuel ramjet motor-thermodynamic cycle and thermodynamic calculation

For achieving high-speed requirement of underwater vehicle,a conceptual engine,which utilizes the hydroreactive characteristic of several metals under supercavitation environment,has been put forward. Especially,in order to obtain specific impulse as great as possible,a dual water injection system is taken into account. Then thermodynamic cycle model,which lead the improvement of power plant and energy system,is introduced in detail,and thermal efficiency is also analyzed. Furthermore,for investigating the performance of this kind of engine system,detailed thermodynamic calculation and analysis are achieved. Especially,regarding hydroreactive metal fuel Mg/AP/HTPB as our target fuel-rich propellant,considering its obvious deficient oxygen property and the energy property of magnesium/water reaction,theoretical calculation method is established by integrating chemical non-equilibrium with chemical equilibrium. Accordingly,low limit of primary water/fuel ratio is determined. In addition,the qualitative and quantitative relationship of performance parameters,such as theoretical specific impulse,nozzle exit temperature,characteristic velocity,etc.,versus water/fuel ratio is investigated respectively.