INVESTIGATION OF SINGLE PHASE MODELS FOR PREDICTING PRESSURE DROP IN NANOFLUID FLOW IN CIRCULAR PIPES

摘要

Macroscopic modeling of hydrodynamic behavior of nanofluid flow in a uniformly heated circular pipe is considered. Single-phase models with Brownian and dispersion viscosity models are evaluated by comparing predicted pressure drop and apparent friction factor with experimental and two-phase Eulerian-Eulerian model results from literature. Single-phase models are capable of predicting heat transfer of nanofluids better when dispersion models are used. However, they fail to accurately predict pressure drop when used with standard viscosity models. Two-phase models on the other hand, can accurately predict both thermodynamic and hydrodynamic field at the expense of computational time. A new viscosity model, which is based on dispersion viscosity, is proposed to increase accuracy of single-phase models in predicting hydrodynamic field of nanofluid flow. Results suggest that single-phase dispersion viscosity model is the most accurate single-phase model.