In the context of simulations of coupled thermal enclosures, we present here a sub-structuring technique adapted to a reduced modal formulation. This technique consists in splitting the geometry into different zones. A modal model is then applied to each zone, and the coupling of the resulting models is performed via a thermal contact resistance. This technique allows the consideration of physical thermal resistances between different components of the geometry, but also the making of fictitious cuts within a continuous domain, when its large size makes it difficult to obtain the global reduced model. Applied to the simulation of a component of a LNG carrier, the use of a sub-structured model with 200 modes allows almost immediate resolution (around 1 second) for a maximum difference near 1 K and an average difference of the order of 0.2 K with respect to a conventional Lagrange finite elements model of shell type, which requires 40 times longer calculation.
Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016.