Modeling of the heat transfer across porous honeycomb structures

R. Coquard1, M. Thomas2, D. Baillis3 and B. Estebe2

1Société « Etude Conseils Calcul en Mécanique des Structures » (EC²MS) , France
2Airbus Operation SAS, France
3Université de Lyon, CNRS, INSA-Lyon, France

Keywords: conduction-radiation coupled heat transfer, Monte Carlo,
property: radiative properties, equivalent thermal conductivity
material: honeycomb structures

In the framework of the reduction of the weight of airplanes, Porous Honeycomb Structures are increasingly used in the aircraft industry. They notably enter in the composition of New Generation Composite Fuselages as thermal insulating shields. Indeed, they present the interest of combining, at the same time, high thermal insulating properties, low density and sufficient mechanical resistance. However, their thermal properties remain relatively unexplored and the number of theoretical and experimental studies concerning the heat transfer through honeycomb structures is very limited. Therefore, the present study is interested in the modelling of the complete heat transfer through this type of porous material. Due to their low density, both conductive and radiative heat transfers have to be taken into account while the contribution of convection could be neglected. The coupled heat transfer is solved by a numerical resolution of the combined Energy and Radiative transfer Equations. The equivalent radiative properties of the material are determined using ray-tracing procedures inside the idealised porous structure while the effective conductivity is estimated via simple but nevertheless realistic analytical formulas. The accuracy of the model developed is validated by comparing the heat transfer coefficient measured by different authors for various honeycomb structures with the theoretical results. Thereafter, a parametric study is conducted by varying the structural dimensions and physical properties of the constituents. This permits us to evaluate the contributions of radiative and conductive heat transfers and to highlight the parameters which strongly influence the thermal performances of the insulating shield.

     Official Sponsors

uni Anter_logo Tziolas_logo_ linseis netzsch