为了进一步推动模型确认方法的发展并明确其具体实施步骤,以圣地亚国家实验室提出的模型确认热传导挑战问题为例,建立了模型确认的贝叶斯框架,并阐述模型确认的思想以及实现的一般过程。模型确认不仅是一个评定仿真模型准确度的过程,而且是一个通过确认结果提高模型预测精度的过程。首先介绍了贝叶斯及不确定性量化的基本理论,强调了模型修正在模型确认中的作用,然后比较了各种模型修正方法的优缺点,最后将贝叶斯模型修正用于热传导问题的模型确认中,得到了比初始模型更准确的预测结果。研究表明贝叶斯模型修正方法用于模型确认能显著提高预测精度。
To further promote the development of model validation and understand the specific implementation steps of model validation, the framework, ideas and general process for model validation utilizing Bayesian method are achieved by the example of model validation thermal challenge problem presented in Sandia National Laboratories. Model validation is not merely a process of assessing the accuracy of a simulation model, but also a process to improve the predictive precision through the model validation results. The basic theories of Bayesian analysis and uncertainty quantification are introduced and several model updating methods are emphasized and compared in model validation. Finally, the Bayesian model updating method is applied to model validation thermal challenge problem, and more accurate prediction results are obtained than those from the initial model. The results demonstrate that the model predictive precision can be significantly improved when utilizing Bayesian model updating method in model validation.
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