دانلود رایگان مقاله تعیین رفتار جز استراتوسفر با استفاده از به روز رسانی مدل المان محدود

ABSTRACT

In general, it is difficult to analyse equipment for space applicability due to the fact that realistic tests on Earth are technically difficult and expensive. To prove the reliability of space systems, a combination of numerical analysis and expensive pre-flight tests is used. However, this paper discusses a new methodology in which a combination is made of low-budget ground tests with a newly developed finite element model updating technique which can deliver a time efficient added value or alternative to the expensive and time-consuming pre-flight tests during thermal analysis. In addition, this contribution shows the influence of several design parameters on the accuracy of thermal simulations for space applications and discusses how this accuracy can be optimised. The methodology is verified within the HACORD project of the REXUS/BEXUS programme.

4. Conclusions

A numerical model, used to predict the thermal behaviour of stratospheric balloon experiments, can be updated through a limited number of ground tests. When the environmental conditions are well described, but contain a number of uncertain parameter values, the updating routine delivers a major accuracy improvement by a factor of 2.2 to 7.6. This method can also be used for other well-known complex environment estimations as a replacement for expensive, long duration and/or dangerous experiments. The boundary conditions of the method are that the uncertain parameter values are independent of the experiment environment. Moreover, the methodology can be used to validate experimental designs for space applications and determine the failure risk of different components or design versions in a fast and cost-efficient way.