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101.
For the purpose of establishing and validating aerodynamic performance predictions at transonic Mach numbers, a wind tunnel test was conducted in the High-Speed Tunnel (HST) of the German-Dutch Wind Tunnels. The test article is the aerodynamic validation model from the Chinese Aeronautical Establishment, which is a full-span scale model representation of a business jet aircraft. The wind tunnel test comprised of parallel deployments of balance, pressures, infrared thermography, and model marker measurement techniques. Dedicated investigations with a dummy support were conducted as well, in order to derive and correct for the interference that the support system imposed on the overall model loads. This enabled the establishment of a comprehensive dataset in which the steady overall model loads, the wing load distribution, the state of the wing boundary layer, and the aeroelastic wing shape were quantified for conditions up to and beyond the cruise Mach number of 0.85. 相似文献
102.
现有的不确定性模型确认方法建立在概率理论基础之上,仅仅适用于随机不确定性因素影响下的模型确认,而不适合随机和区间变量共存条件下的模型确认问题。针对这一问题,研究了随机和区间变量共存条件下的模型确认方法。首先,分析了随机和区间变量共存条件下数学模型的特点;然后,运用概率方法和区间理论,提出了一种新的模型确认指标,通过模型响应量的上下界分布函数(CDF)与实验响应量的上下界经验CDF之间差异,来度量随机和区间输入变量共存条件下模型预测与实际物理实验结果之间的不一致性;讨论了所提指标的数学性质,给出了指标的计算方法和步骤;最后,采用一个数字算例和一个工程算例验证了所提指标在随机和区间输入变量共存条件下进行模型确认的可行性和有效性。 相似文献
103.
模糊软件可靠性模型不仅适用于刻划测试阶段的软件可靠性行为,而且适用刻划确认(验收)阶段的软件可靠性行为。并给出在确认(验收)阶段判定软件是否达到可靠性目标的准则。 相似文献
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提出了一种以星上有效载荷的形式搭载在低轨综合卫星平台上的PNT服务系统,可作为GNSS系统的补充、备份和验证手段。本文总结了低轨卫星PNT服务的发展现状,提出了该低轨PNT服务系统的设计方案和总体架构,分析了系统的工作原理、服务性能以及对GNSS系统的可补充和验证性。最后给出了系统建设需要研究的几项关键技术,初步论证了该PNT系统的可行性和技术可实现性。 相似文献
106.
《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2020,65(1):138-151
Based on the method for establishing a global plasmaspheric model using observations from COSMIC and MetOp-A orbit determination GNSS receivers, Chen et al. (2017) obtained a global plasmaspheric total electron content product with a spatial resolution of 2.5° × 5° and a time resolution of 4 h. In this paper, we use those global plasmaspheric electron content product in 2008, 2010, 2011, 2012, 2014 for 1446 days to establish a global plasmaspheric empirical model based on empirical orthogonal function (EOF). The model can well characterize the spatiotemporal variation of plasmaspheric electron content (PEC) and the influence of solar radiation on it. Only the first four orders of EOF sequences can characterize the 98.43% features of the original PEC dataset. The principal component coefficient Pk is decomposed twice during modeling, and the combination of trigonometric function and linear function is used to model Pk to characterize the solar cycle, annual cycle, semi-annual cycle and quarter-cycle variation. We compare the PEC model values with the actual observation data, the results show that the empirical PEC model values are highly correlated with the actual observations. The correlation between the two is above 0.96, and the RMS maximum of the difference between the PEC model values and the observed values are 0.70 TECU, and the average of the difference between the PEC model values and the observed values are −0.18 TECU, respectively. In addition, we validate the reliability of the global plasmaspheric model established by two empirical orthogonal function decomposition method using actual observation data, according to the global distribution of the differences between the PEC model values and the observed values in low solar activity and high solar activity, it can be seen that under low solar activity and high solar activity conditions, the model has good adaptability. 相似文献
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108.
叙述了空客A380飞机可靠性工程中的确认和检验过程的方法论,并就具体案例进行了分析,介绍了发动机联盟如何将确认和检验过程应用于GP7200发动机的设计中以满足安全性和可靠性的要求。 相似文献
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