立式混合机桨叶运动轨迹分析

介绍利用坐标变换原理建立双桨行星立式混合机桨叶运动轨迹数学模型的方法及利用计算机绘制桨叶运动轨迹的技术，并以该数学模型分析了空心桨叶棱边与锅壁最小间隙的分布规律，同时分析了公转和自转变比不同时，桨叶和锅壁间死区对被混物料混合效果的影响     

共硝化及TATN／DADN共硝化合成研究

介绍了共硝化法合成混合硝酸酯的特点及其应用价值,在此基础上较详细地研究了TA(一种三元醇)和DA(一种二元醇)共硝化合成TATN/DADN混合硝酸的工艺条件,分析讨论了各种影响因素对共硝化产率、纯度、TATN/DADN比值的作用,提出了氧化副反应和乳化现象发生的原因及抑制方法。     

三维实体模型向二维工程图纸的转化

本文在基于ＡｕｔｏＣＡＯＲ１２支撑软件的基础上，利用其ＡＤＳ和ＡＭＥ函数，讨论了三维实体模型向二维工程图纸的转化的问题，分析了三维实体的三向投影及三个视图的对齐关系。     

固体燃料冲压发动机性能预示

为研究弹用固体燃料冲压发动机的工作性能,建立了其性能预示模型。在此基础上对高炮用固体燃料冲压发动机的工作性能进行了预示、分析。结果表明:当飞行高度由0增大至10km时,发动机的燃速、推力均下降约50%;当飞行马赫数由2.5增大至3.0时,燃速增大25%~35%,推力增大20%;随着燃料的不断消耗,发动机推力变化量小于10%;在设计状态下推力有一定的余量,能够保证发动机正常工作。     

温度冲击试验对固体发动机喷管堵盖结构影响的仿真分析

温度冲击试验可模拟极端温度环境对固体发动机结构的影响。本文利用三维有限元方法,通过热-机耦合,分析了一种固体发动机喷管堵盖在温度冲击中的温度、应力和应变的变化情况。结果表明:温度冲击中,喷管堵盖内存在温差,最大可达46℃;存在内应力,在铝合金支撑件/EP密封件环形界面处最大,低温-50℃时达18.1 MPa,是堵盖最先破坏的位置;EP密封件是堵盖的最薄弱环节,粘接结构最大内应力11.6MPa,分离结构9.1 MPa;得出了温度冲击下,影响喷管堵盖结构完整性的因素,表明选用低模量和合适线胀系数的密封材料,采用常温成型方法,脱开密封件/支撑件间环形交界面,可有效降低密封件/支撑件的内应力;含GFM/EP/铝合金喷管的真实发动机温度冲击试验结果与预估结果吻合。     

运载火箭固体发动机复合材料技术发展现状

介绍了代表目前运载火箭固体发动机材料技术水平的欧洲织女星(Vega) 三级发动机和作为未

来织女星和新一代运载火箭技术验证的Zefiro 40 发动机以及日本Epsilon 固体发动机的技术特点及其复合材

料与工艺研究进展,结合我国运载火箭固体发动机材料的技术现状,提出发展建议。

     

Improving surface integrity when drilling CFRPs and Ti-6Al-4V using sustainable lubricated liquid carbon dioxide

In the quest for decreasing fuel consumption and resulting gas emissions in the aeronautic sector, lightweight materials such as Carbon Fiber Reinforced Polymers (CFRPs) and Ti-6Al-4V alloys are being used. These materials, with excellent weight-to-strength ratios, are widely used for structural applications in aircraft manufacturing. To date, several studies have been published showing that the use of metalworking fluids (MWFs), special tool geometries, or advanced machining techniques is required to ensure a surface quality that meets aerospace component standards. Conventional MWFs pose a number of environmental and worker health hazards and also degrade the mechanical properties of CFRPs due to water absorption in the composite. Therefore, a transition to more environmentally friendly cooling/lubrication techniques that prevent moisture problems in the composite is needed. This research shows that lubricated LCO₂ is a viable option to improve the quality of drilled CFRP and titanium aerospace components compared to dry machining, while maintaining clean work areas. The results show that the best combination of tool geometry and cooling conditions for machining both materials is drilling with Brad point drills and lubricated LCO₂. Drilling under these conditions resulted in a 90 % improvement in fiber pull-out volume compared to dry machined CFRP holes. In addition, a 33 % reduction in burr height and a 15 % improvement in surface roughness were observed compared to dry drilling of titanium.     

Robust spline-line energy management guidance algorithm with multiple constraints and uncertainties for solid rocket ascending

For the solid rocket with depletion shutdown system, effective energy management is significant to meet terminal constraints by exhausting excess energy. Several traditional energy management algorithms cannot satisfy the altitude constraint and path constraints are not sufficiently considered. The velocity adjustment capability of these algorithms is limited and the uncertainties are not considered. Based on the on-line programming of velocity capability curve, Spline-Line Energy Management(SLE...     

Cooling and lubrication techniques in grinding:A state-of-the-art review,applications, and sustainability assessment

Grinding technology is an essential manufacturing operation, in particular, when a component with a superfinishing and an ultra-resolution is yearned. Meeting the required strict quality checklist with maintaining a high level of productivity and sustainability is a substantive issue. The recent paper outlines the lubrication and cooling technologies and mediums that are used for grinding. Furthermore, it provides a basis for a critical assessment of the different lubrication/cooling techniques ...     

进气道出口截面形式对补燃室掺混性能的影响研究

为研究进气道出口截面形式对补燃室掺混气动特性和燃烧性能的影响，本文对双下侧布局形式的固冲发动机内流场进行数值模拟，对比分析了补燃室相同压比下两种不同进气道出口截面形式在不考虑燃气的混合和反应时掺混段的气动特性和考虑燃气反应时补燃室的燃烧性能。结果表明：两股空气掺混过程中，研究的两种进气道出口截面方案的整体总压损失大致相同，但进气道圆形出口截面的掺混段内流线表现为不稳定的螺旋点形态，相比于方形出口截面的掺混段，其使气流掺混更剧烈，短距离内掺混已经很均匀，且旋流强度小；在考虑燃烧时，进气道圆形出口截面对应的补燃室出口总压恢复系数比方形截面的高约2%，方形进气道出口截面的补燃室出口截面总燃烧效率为95.58%，而圆形截面的达到99.86%。