Finite-element view-factor computations for radiant energy exchanges

T Muneer,S Ivanova,Y Kotak,M Gul

doi:10.1063/1.4921387

Abstract

Radiation heat transfer has very many applications within the building services sector. CIBSE (Chartered Institution of Building Services Engineers) Guide A provides the physics background and the relevant mathematical functions for radiant energy exchanges between surfaces of different configurations in chapters 2 and 5. The aim of this article is to present procedures for inter-surface radiant energy exchange that range from the most simple (macro-) to most general formulations that are based on a micromesh, finite-element approach. The justification for such detailed procedures and their applicability within the modern building energy simulation software is also covered.

Highlights

In any given society buildings in general have been identified to be one of the most energy consuming sector
The building services community has responded to the above challenge and one of the positive actions undertaken was refining of building energy simulation tools
In a recent publication the present research team has presented a case for obtaining building cooling load profile from a numerical solution of the fundamental heat conduction equation[2]. Another example that may be cited here is the work of Laccarino et al (2010)[3] who developed a building energy model that coupled a Computational Fluid Dynamics (CFD) tool with heat transfer information from an energy simulation tool

Summary

INTRODUCTION

In any given society buildings in general have been identified to be one of the most energy consuming sector. CFD simulation software allows to predict the impact of fluid flow on any product throughout the design and manufacturing as well as during end use. In a recent publication the present research team has presented a case for obtaining building cooling load profile from a numerical solution of the fundamental heat conduction equation[2] Another example that may be cited here is the work of Laccarino et al (2010)[3] who developed a building energy model that coupled a CFD tool with heat transfer information from an energy simulation tool. In brief, due to increased computing power that is available at ever decreasing cost there is a general trend towards the incorporation of fundamental physical laws and processes, rather than use of empiricism within building energy simulation tools. The aim of this article is to present procedures for inter-surface radiant energy exchange that range from the most simple (macro-) to most general formulations that are based on a micromesh, finite-element approach

Radiation exchange between any two surfaces

Comparison and difference between configuration factor and view factor

Findings

View factor algebra