星孔装药燃面退移图象显示中的特殊问题

介绍了采用双三次均匀B样条曲面法构造星孔装药燃面退移图象中，夹直纹面的曲面；具有脊线曲面的反算拟合；燃面拟合的边界条件及曲面加密网格的求解等特殊问题。     

三维组合药型单室双推力发动机燃面与内弹道计算

基于有限容积的思想，构造任意形状的三维药柱燃面退移通用计算方法，并推广应用于嵌金属丝推进剂的燃面计算。计算过程只关心燃面的始态和终态，可完全避开错综复杂的几何燃面变化规律，实现任意药型下多推进剂、变燃速燃面退移的计算机数值模拟。在此基础上，对三维组合药型单室双推力发动机进行了喉部烧蚀条件下的内弹道计算，同时与试验结果进行比较，取得了较好的效果。     

固液发动机实验燃烧器的气固耦合传热计算

针对固液火箭发动机中复杂的燃烧、传热过程,在FLUENT软件的平台上,采用气固耦合传热计算的方法模拟了二维扩散燃烧实验器中的温度、组分分布,并利用动网格方法模拟了固体燃面的不规则热解退移。稳态流场计算的结果和燃面动态退移情况都验证了扩散火焰距燃面的距离和燃面上方主流流速是影响退移速率的主要因素。此方法可以较好地模拟固液火箭发动机中复杂的非定常传热和燃面退移过程,较准确地预示固液发动机的内弹道性能。     

含铝固体燃料冲压发动机工作性能分析

为探究含铝固体燃料冲压发动机的燃烧特性和工作性能，基于纳米铝颗粒和端羟基聚丁二烯（HTPB）的混合固体燃料，采用雷诺转捩模型、颗粒表面反应模型和涡概念耗散模型，建立了二维两相湍流燃烧模型；数值计算分析了含铝固体燃料冲压发动机内流场，以及不同含铝质量分数和粒径下的燃面退移速率、推力与比冲。结果表明：发动机的进气条件对颗粒相的燃烧与运动起主导作用；与纯HTPB推进剂相比，添加质量分数为5%的铝颗粒能够提高补燃室压强和温度，增大燃烧室内高温区面积，可使推进剂平均燃面退移速率提高18.53%，发动机推力提高21.37%，密度比冲提高2.38%，适当增加铝颗粒含量或减小粒径，对提高推进剂燃面退移速率、发动机推力和密度比冲具有积极作用。     

三维燃烧移动边界计算网格示踪技术

以任意设计的固体火箭发动机装药几何形状为对象,分析研究了燃面燃烧移动的基本规律,提出了一种三维复杂燃烧移动边界的示踪方法。它可以用于流场计算、发动机性能预示计算和侵蚀燃烧计算中,也可以发展成为一种燃面计算的新方法。文中以假想三维局部翼形装药为例进行了数值计算。     

固液混合发动机燃面退移规律辩识方法

为了以尽可能少的试验对固液混合发动机的燃面退移规律进行辨识，采用在一发试验中适当调节工作参数的方式，并结合瞬时燃面退移速率求解方法，总结出了一套固液混合发动机燃面退移规律辨识方法进行了试验验证，结果表明：采用二维药型的固液混合发动机，通过一发试验即可较准确地掌握其燃面退移规律，还可应用于其它同种类型的固液混合发动机内弹道性能预测。     

固液火箭发动机工作过程三维数值仿真

根据固体燃料壁面与气相间的流固耦合得出了固体燃料燃速模型,对采用星形装药的H₂O₂/HTPB(hydroxyl-terminated polybutadiene)固液火箭发动机进行了燃烧流动三维数值仿真,得到了流场参数的分布及不同位置的固体燃料燃速,与二维轴对称仿真结果进行了对比.计算结果表明:装药截面的火焰层形状与装药星孔型面形状相似,但火焰层厚度与位置在星根与星角处存在差异;随着轴向位置的增加,氧化剂不断消耗,火焰层向通道中心移动;固体燃料燃速与氧化剂流率及不同装药位置有关,其大小随氧化剂流率的增加而增加,星根处燃速比星角处大;在相同氧化剂流率下,三维星形装药比二维轴对称装药的平均固体燃料燃速大.      

三维燃面计算方法的比较与实体造型方法的特点

对已有的几种三维药柱燃面推移模型进行了分析比较，提出了一种新方法－三维实体造型法，并进行了翼柱形装药的工作过程仿真计算，证明该方法具有通用性强，使用方便，输出信息完备，计算精度高等特点，适合在工程设计中推广应用。     

翼柱型装药燃烧室三维非定常湍流的数值模拟

采用к－ε双方程湍流模型,以ＳＩＭＰＬＥ计算程式结合ＴＤＭＡ法求解翼柱型装药固体火箭发动机燃烧室内三维非定常不可压流Ｎ－Ｓ方程。在建立翼柱型装药简化模型的基础上,采用边界标志来表达燃面推移,采用从二维到三维的初场给定方法结合多重网格法,求出了多个时间步的非稳态流场结构。计算结果表明：燃烧室内旋涡运动呈现一定的空间与时间分布,周向加质导致燃气通道横断面上轴向速度分布的极不均衡。     

固体火箭发动机装药的计算机辅助设计

本文提出了面向微型计算机的计算机辅助设计方法和程序,包括装药几何计算、内弹道性能计算及强度校核图形显示等一体化设计的计算机程序.目前已开发了三维翼柱型装药的模块化结构程序分支,可在微机PC-286/386上进行.本程序通用性广,精度高,可以很方便地扩充到其他药型.     

三元整体叶轮的曲面造型及其计算机辅助制造技术

针对一种三元整体叶轮,采用B样条方法对叶片中性面上顶部和根部的两组数据点进行了插值曲线的反算,进而构造出直纹面形式的叶片中性面和叶片曲面;研究了在五坐标机床上采用球头棒铣刀侧铣加工叶轮时的刀位计算方法,给出了在UG环境下的叶轮曲面建模方法及其数控加工仿真步骤。     

Developing the next generation cockpit display system

The goal of advanced cockpit display systems is to present large amounts of information quickly and in an understandable format, enabling the aviator to improve mission performance. Current front-line cockpit display systems utilize low-resolution analog video to present two-dimensional (2-D) images on many separate displays. The future cockpit will be capable of integrating large picture digital video with three-dimensional (3-D) and 2-D color images. This system will be capable of rendering icons, maps, and world-views. It will be compatible with head mounted displays and multiple large displays to improve war-planning and combat aviator situational awareness. We are developing a massively parallel 3-D renderer which will be capable of updating 500,000 3-D triangles per second with shading, lighting, transparency, texture mapping, and hidden surface removal. The renderer design employs a massively parallel architecture with 1,024 ALUs per chip to display one million anti-aliased vectors per second. Current high end workstations are capable of these display goals, but fall far short of military reliability, size, and power requirements. The rendering system will be small enough to fit on one board, extensible to dual-seat configuration, and capable of up to eight windows per display channel     

带侵蚀效应的三维双燃速装药固体火箭发动机点火过程

针对三维双燃速装药固体火箭发动机,采用商用CFD计算软件的用户自定义方程对点火瞬态过程中的侵蚀燃速、燃面温度、质量源项、动量源项、能量源项及点火器入口等进行了二次开发,并进行了考虑侵蚀效应的点火瞬态过程流场仿真计算,与地面点火试验内弹道数据进行了对比分析。结果表明:点火初期发动机头部的气流流动十分复杂,且头部压强随时间变化十分剧烈;堵盖打开会造成头部升压梯度振荡,并产生负升压梯度;仿真与试验结果符合较好,说明采用一维非定常固相传热方程计算三维燃面温度可以满足当前工程要求,计算方法正确有效。      

Internal ballistic simulation of multi-burning-rate solid rocket motor based on parameterized feature CAD modelInternal ballistic simulation of multi-burning-rate solid rocket motor based on parameterized feature CAD model

Internal ballistic simulation(IBS)method of multi-burning-rate solid rocket motor(SRM)was developed based on 3-D burning regression method by parameterized feature CAD model(PFCADM)and lumped parameter,in consideration of time-dependent,erosive-burning-effect from internal ballistic numerical algorithm.By driving multi-parameter CAD model based on PFCADM,the approach is capable of conducting the geometric regression simulation of various grain combinations of complex configurations with different burning rates.Through suitably simplifying the internal ballistic numerical algorithm,the problems of coupling geometric regression simulation of sub-grains of different burning rates and high computational consumption of internal ballistic calculation were solved.One tri-burning-rate grain motor,which had been firing-tested,was used as the validation case of simulation.The results show that,with the 3-D grain regression model and sufficient accurate internal ballistic algorithm,the method realizes IBS of the case in low computationalconsumption prediction of its performance within the accuracy of 2% during 1hclock-time.The application of the method provides a practical approach to aid SRM design of multi-burning-rate grain.     

Internal ballistic simulation of multi-burning-rate solid rocket motor based on parameterized feature CAD model

Internal ballistic simulation (IBS) method of multi-burning-rate solid rocket motor (SRM) was developed based on 3-D burning regression method by parameterized feature CAD model (PFCADM) and lumped parameter, in consideration of time-dependent, erosive-burning-effect from internal ballistic numerical algorithm. By driving multi-parameter CAD model based on PFCADM, the approach is capable of conducting the geometric regression simulation of various grain combinations of complex configurations with different burning rates. Through suitably simplifying the internal ballistic numerical algorithm, the problems of coupling geometric regression simulation of sub-grains of different burning rates and high computational consumption of internal ballistic calculation were solved. One tri-burning-rate grain motor, which had been firing-tested, was used as the validation case of simulation. The results show that, with the 3-D grain regression model and sufficient accurate internal ballistic algorithm, the method realizes IBS of the case in low computational-consumption prediction of its performance within the accuracy of 2% during 1h clock-time. The application of the method provides a practical approach to aid SRM design of multi-burning-rate grain.      

涡切片图象立体重建

 <正> 1.引言 激光片光技术和流体中微粒的光散射效率逐步提高;从烟雾、水汽到激发诱导荧光使流动可视化程度不断开拓。许多研究工作需要通过观察切片照片获得对复杂流动整体结构的理解。因此,将系列二维切片照片重建成立体图象是十分有意义的。 近年来这方面比较典型的工作有Jimener的平面混合层和Agui and Hesselink的共轴喷流重建,分别在平面型和封闭柱面型的不同气流混合界面研究涡系的生成和发展。用涡迹切片重建的三维图象能清楚地显示涡的内部结构,对提供合理的流动假说和计算模型有重要意义。     

星形内孔装药的非均匀侵蚀燃烧

本文对星形内孔装药的一个单元星角内的侵蚀燃烧进行实验研究。实验表明沿装药燃烧周界侵蚀燃烧是不均匀的, 星谷附近的燃速大于星尖附近的燃速。侵蚀燃烧的不均匀程度与燃气平均流速、燃气压强以及星角的大小有关。二维流场计算与实验结果对照说明, 流速分布不均匀是造成侵蚀燃烧不均匀的主要原因。      

Solid rocket motor propellant grain burnback simulation based on fast minimum distance function calculation and improved marching tetrahedron method

To efficiently compute arbitrary propellant grain evolution of the burning surface with uniform and non-uniform burning rate for solid rocket motor, a unified framework of burning surface regression simulation has been developed based on minimum distance function. In order to speed up the computation of the mini-mum distance between grid nodes of grain and the triangular mesh of burning surface, a fast distance querying method based on the equal size cube voxel structure was employed. An improved marching tetrahedron method based on piecewise linear approximation was carried out on second-order tetrahedral elements, achieved high-efficiency and adequate accuracy of burning surface extraction simultaneously. The cases of star grain, finocyl grain, and non-uniform tube grain were studied to verify the proposed method. The observed result indicates that the grain burnback computation method could realize the accurate simulation on unstructured tetrahedral mesh with a desirable performance on computational time.     

模拟飞机迎风面三维积冰的数学模型

针对飞机迎风面的积冰建立了三维积冰模型,给出了模型的求解方法和求解步骤.该模型不但可以模拟明冰积冰、霜冰积冰和不结冰三种情况下的冰层生长,还可以模拟未凝结水膜在冰层表面的流动,而且在求解过程中可以自动判断过冷水滴撞击到迎风面以后的积冰形态.利用该模型数值模拟了翼型与平板相正交而形成的简单三维结构上的积冰过程,并将所得结果中翼型上三维冰形的二维截面与美国航空航天局(NASA)的冰形进行了对比,获得了较好的一致性,证实了所建立的积冰模型是合理的.