A New Algebraic Reynolds Stress Turbulence Model for Prediction of Wall-Affected Three Dimensional Room Airflows

In the past various experimental investigations about room airflows were published. But most investiagtions are limited regarding measurements positions (restricted gflow patttern) and the availability of turbulent quantities (Reynolds-Stresses, entrainment, macroscopic instabilities etc.) based on the avaiable experimental data a targeted improvement of turbulence models is difficult. Therefore a complex three dimensional room airflow situation was investigatedwith three-dimensional Particle Image Velocmetry. Detailed informatiom of the floww, the Reynolds-stress distribution and the entertainment are presented. Based on the experimental results the behaviour of RANS-based turbulence models in predicting roomairflow is discussed. In this context, it is shown that intensive anisotropic Reynolds stresses near the wall arise and influences the airflow pattern. For this reason a new algebraic Reynolds stress turbulence model - which can in princible reproduce the turbulence anisotropic behaviour- is proposed. Compared with the linear eddy viscoity turbulence models the new nonlinear model agrees clearly better with the presented experimental findings.