Applications of the Volume Averaging Theory to Momentum and Heat Transfer within Complex Flow Systems

Abstract

The volume averaging theory (VAT) developed in the study of porous media is quite powerful in attacking difficult problems associate with momentum and heat transfer in complex fluid flow system, such as heat exchangers, combustors and engine nacelles. Applications of VAT to momentum and heat transfer within complex heat and flow systems are reviewed in this lecture. Such difficulties arise from geometrical complexities and conjugate heat transfer between fluids and solids. In order to overcome the difficulties, the set of the governing equations are integrated over a local control volume to obtain the macroscopic governing equations. The sub-scale (i.e. pore-scale) modeling is carried out to close the set of the equations. Subsequently, the unknown model constants are determined by conducting direct numerical simulations using a structural unit model. Various applications in heat exchangers, composting systems and human bodies are discussed to elucidate the validity of the present procedure.