Numerical simulation of turbulent airflow in a ventilated room: Inlet turbulence parameters and solution multiplicity

Abstract

In this study, airflow and temperature distributions in the well-known International Energy Agency (IEA) Annex 20 room are predicted numerically to investigate the effects of the inlet turbulence intensity and the length scale on the flow characteristics, while considering the possibility of solution multiplicity related to chaos theory. The flow is considered to be turbulent, steady, incompressible, and two-dimensional. Computations are performed using the standard k-epsilon, RNG k-epsilon, standard k-omega, and shear stress transport k-omega turbulence models with scalable and automatic wall functions, and the results are compared with numerical and experimental results from the literature. The validated turbulence model is then used to investigate the effects of the turbulence intensity and the length scale. At a low inlet turbulence intensity value (Tu = 0.01), the length scale variation has no influence on the flow pattern. However, the length scale affects the flow pattern at a high inlet turbulence intensity value (Tu = 0.4). At constant low and medium length scale values, an increase in the inlet turbulence intensity from 0.01 to 0.4 affects the flow pattern. However, an increase in the turbulence intensity has no influence on the flow pattern at a constant high length scale value.