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张勇 《中国民航学院学报》2011,(5):38-41
数据交换平台是民航公共信息网络平台的核心系统。提出了基于XML标准和Web Service技术的民航数据交换平台系统设计思想,提出了系统的建设思路和总体目标、设计原则和技术措施。描述了数据交换平台的数据交换流程和系统体系结构。 相似文献
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本文介绍了工业环境对产品数据交换的需求、交换的方法,以及国际上主要的数据交换标准IGES和STEP。 相似文献
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基于高拟真度模型的高超声速飞行器静气动弹性优化 总被引:2,自引:2,他引:0
为解决基于计算流体动力学(CFD)和计算结构动力学(CSD)高拟真度模型的静气动弹性优化过程中模型更新自动化困难、求解速度慢的难点,提出了基于几何主模型技术的CFD/CSD一体化参数化建模方法和基于网格单元修正的常体积四面体(CVT)数据交换技术,并引入响应面模型来降低气动弹性优化求解难度.通过AGARD 445.6机翼静气动弹性分析对上述方法的可行性和有效性进行了验证;并以某高超声速飞行器为例,采用基于二次响应面的多目标优化算法进行了CFD/CSD气动弹性分析与优化,优化后飞行器升阻比增加16%,结构质量减少9%,且响应面模型精度拟合误差不超过1.5%.计算结果表明:所发展的CFD/CSD一体化参数化建模与优化方法能够有效地解决高拟真度模型的静气动弹性优化问题. 相似文献
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关于在STEP标准基础上进行数据交换的初步研究 总被引:2,自引:0,他引:2
基于国际标准STEP,论述了在不同CAD/CAM系统之间进行数据交换的STEP交换文件的结构,介绍了数据交换中前、后置处理器的一般设计方法,并通过实例说明建立在STEP标准基础上的不同CAD/CAM系统之间的有限元方法计算结果的数据交换过程。 相似文献
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基于自适应混合网格的脱体涡模拟 总被引:1,自引:1,他引:0
基于混合网格和CGNS(CFD General Notation System)数据结构,建立了一种各向同性加密/稀疏的网格自适应方法。在悬空点的后处理中,让含有悬空点的单元转化为任意多面体,从而简化了自适应单元剖分模版,同时自适应网格单元之间可完全相容,自适应生成的网格能够直接用于可处理任意多面体的流场求解器。将该自适应方法与脱体涡模拟(DES)算法相结合,开展了65°后掠三角翼大迎角流动的数值模拟应用,并与初始网格的模拟结果进行了详细比较。对比表明:采用网格自适应方法适当增加局部网格量,能够以较小的成本迅速提高三角翼背风区的空间分辨率,增强数值模拟对小尺度涡系结构的解析能力,从而弥补了基于混合网格的脱体涡模拟中常用二阶格式计算的空间分辨率相对偏低、不利于湍流多尺度结构精细模拟的不足。 相似文献
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基于非定常气动力辨识技术的气动弹性数值模拟 总被引:17,自引:6,他引:11
选择离散型输入输出差分模型,运用最小二乘方法进行非定常气动力建模,并将辨识得到的降阶模型用于气动弹性的数值模拟。1个马赫数下的颤振临界点的计算仅需调用一次非定常流场求解器。计算精度保持与非定常欧拉方程计算方法相当的同时计算效率提高了1~2个量级。计算了跨声速具有S型颤振边界的气动弹性标准算例-Isogaiwing和三维气动弹性标模算例AGARD445.6,辨识模型计算边界与非定常Euler方程计算结果吻合。证明非定常气动力辨识技术可以提供高效的高精度的气动弹性分析。 相似文献
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R. I. Ganiev N. A. Nikolaev V. A. Fafurin A. N. Sabirzyanov V. B. Yavkin 《Russian Aeronautics (Iz VUZ)》2008,51(4):377-381
The results of analyzing a flow in the measuring pipeline with a standard orifice plate within the range of 5×104 ≤ Re ≤ 108 using the computational fluid dynamics (CFD) methods are presented. A deviation of the design value of the discharge coefficient from the value indicated in the standard served as a criterion for choosing a turbulence model and grid. The calculation data for the discharge coefficient obtained with the use of RANS turbulence models are given and it is shown that the CFD methods make it possible to calculate the discharge coefficient of a variable-pressure drop flowmeter with a precision that meets the standard requirements. 相似文献
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《Progress in Aerospace Sciences》2001,37(5):477-495
In the early days, store separation tests were conducted in a hit or miss fashion—the stores would be dropped from the aircraft at gradually increasing speeds until the store came close to or sometimes actually hit the aircraft. In some cases, this led to loss of the aircraft, and made some test pilots reluctant to participate in store separation flight test programs.During the 1960's, the Captive Trajectory System (CTS) method for store separation wind tunnel testing was developed. The CTS provided a considerable improvement over the hit or miss method, and became widely used in aircraft/store integration programs prior to flight-testing. However, since fairly small-scale models had to be used in the wind tunnel tests, in many cases the wind tunnel predictions did not match the flight test results. No mechanism was then in place to resolve the wind tunnel/flight test discrepancies.During this same time frame Computational Fluid Dynamics (CFD) had finally matured to the point of providing a trajectory solution for a store in an aircraft flowfield. However, since the computational tools were necessarily (due to computer resource limitations) limited to linear techniques, and since most store separation problems occur at transonic speeds, these tools had limited application.Recent advances in computer resources have greatly improved the capability of CFD to predict store release characteristics. Instead of using linear or approximate schemes, time dependent Euler and Navier Stokes trajectories could be computed in a reasonable time frame.Three international CFD Challenges, held during the last decade of the 20th century, have shown that CFD can not only match wind tunnel test data, but also predict flight test trajectories for complex stores at transonic speeds. It appears that CFD has matured to the point that it can be usefully integrated into aircraft/store compatibility programs. 相似文献
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Charles HIRSCH 《中国航空学报》2006,19(2):105-113
QNET—CFD是欧盟R&D项目开发的一个主题网络,该网络讨论了计算流体力学(CFD)供工业应用应具有的品质和可信度,其主要目的是以系统和质量控制的方式收集CFD和实验数据,建立两者相容的知识库(KB),以此为基础,支持对CFD进行指导和评估。QNET—CFD围绕覆盖下述工业部门的6个主题(TA)组成:外流空气动力学;燃烧和传热;化学过程、热水力学和核安全:土木建筑和HVAC;环境;涡轮机内流。其主要成果是建立了具有面向用户界面及丰富的实验和CFD数据的知识库,这些数据来自于大量实验数据,分为53种应用挑战(AC)和43种基本流动状态(UFR)。除对上述6个主题领域中每一个的科学发展动态给出述评外,KB还包含了对大多数应用挑战如何利用CFD的最实际的建议,这被视为QNET—CFD最有意义的贡献,CFD的可信度和质量水平将因此得以进一步提高。 相似文献
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《中国航空学报》2023,36(1):231-245
Focusing on the internal flow and heat transfer analysis, a platform for the performance evaluation of the Secondary Air System (SAS) is developed. A multi-fidelity modeling technique has been developed in a turbofan engine model under different flight conditions. A turbine blade cooling model which integrates external heat transfer calculations and coolant side modeling with common components is proposed. In addition, the Computational Fluid Dynamics (CFD) method is selected to capture the complex flow field structure in the preswirl system. The validity of the SAS models is compared with publicly available data. An elaborately designed cooling system for the AGTF30 engine is analyzed through three main branches. It is found that the 1D-3D modeling technique can provide more accurate predictions of the SAS for the AGTF30 engine. The results demonstrate the versatility and flexibility of the SAS models, thereby indicating the capacity of meeting most of the demands of flow and thermal analysis of the SAS. 相似文献
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民机的空调组件舱位于非增压区,其内部包含有换热器、压缩机等高温环控组件。为避免高温对舱体结构产生危害,需要采用冷却措施。以某机型的空调组件舱通风冷却方案为参考,建立了空调组件舱通风系统的几何模型,并以此模型为基础进行了CFD仿真计算。对计算结果进行分析后,提出了方案的缺陷,并为后续的方案设计提出了关注点。 相似文献
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高升力标模确认计算研究 总被引:1,自引:0,他引:1
针对高升力标模NASA Trapwing全展襟翼构型展开确认计算研究。采用N-S方法,预测高升力模型的流动状态,分析高升力的流动现象及机理,评估自主研发的WiseManPlus软件及WoF90软件预测高升力流动的能力。通过对网格生成、计算策略及数据分析等各个环节进行分析,制定出一套适用于高升力模型工程应用的CFD计算方法,得到与实验值吻合较好的计算结果。结果表明,目前所采用的结构网格求解器WiseManPlus软件及混合网格求解器WoF90软件计算精度相当,适用于模拟高升力流动。 相似文献