Paper Conference

Proceedings of Building Simulation 2021: 17th Conference of IBPSA


Solar Load modelling in OpenFOAM for indoor HVAC applications

Shadab Mohammed, Sadashiv Khadilkar, Unnati Jadhav, Sandip Jadhav
Center for Computational Technologies Pvt. Ltd., India

Abstract: Achieving thermal comfort inside buildings with large glass facades is challenging, especially concerning the total energy consumption required for maintaining the desired cooling and comfort. The solar load constitutes a major contributing factor in the total load of the system. The semi-transparent glazing material or coating is applied on glass walls to reduce energy consumption. In CFD, the solar load is modelled by combining the solar calculator with the ray-tracing algorithm and applying the load on the surfaces that directly exposed to the sun. The inbuilt solar load model that comes with OpenFOAM is not suitable for indoor HVAC simulations. Additionally, it has no support for semi-transparent glass walls, and it is also not compatible with convective heat flux boundary conditions. Therefore, this paper focuses on overcoming the shortcoming of inbuilt solar load model by developing our in-house codes and methodology to model the solar load accurately. The current solar load module can cope with transient conditions resulting from the apparent sun motion, but it does not support the glass walls' incident angle-dependent glazing properties. The code implementation and its results are validated with the ASHRAE handbook and Solpos NREL code. To further evaluate our model qualitatively and quantitatively, software comparison case studies are performed with ANSYS FLUENT software. The results show that our implementation is correct and is in good agreement with the commercial software package results.
Keywords: CFD, Solar Load, Indoor HVAC Simulations, Semi-transparent Glass Walls, OpenFOAM Development
Pages: 1818 - 1824