Detailed and fast calculation of wall surface temperatures near thermal bridge area

• Published in: Case studies in thermal engineering 2021-06, Vol.25, p.100936, Article 100936
• Main Authors: Choi, Jae-Sol, Kim, Chang-Min, Jang, Hyang-In, Kim, Eui-Jong
• Format: Article
• Language: English
• Subjects: FEM; Numerical model; Reduction technique; State-space model
• ISSN: 2214-157X; 2214-157X
• DOI: 10.1016/j.csite.2021.100936

The popularity of digital-twin technology has increased the demand for a fast and accurate model for prompt analysis. This work proposes a low-order but accurate numerical model for the thermal analysis of wall-window joint surfaces. A simple method to develop such a model is presented. An ABAQUS-based extraction method was developed to quasi-automatically define a state-space model for the target cases used, which may reduce the amount of elaborate programming work required. Then, an order reduction technique was applied to the state-space model. The results showed that the state-space model obtained from ABAQUS describes almost the same thermal responses as the reference ABAQUS simulation model. After reduction, the proposed model with an order of 10, equivalent to 10 equations, sufficiently described the dynamics of temperature variations, with an error of less than 1%. The model conversion to state-space formulism and reduction technique significantly decreased the CPU time by more than 30,000 times (from 79.5 s to 0.002 s).