Airflow characteristics under planar opposed ventilation jets in a controlled indoor environment

¹ Department of Mechanical Engineering, School of Engineering, Aalto University, Espoo, Finland
² Institute for Energy Efficient Buildings and Indoor Climate, E.ON Energy Research Center, RWTH Aachen University, Aachen, Germany
³ College of Urban Construction, Nanjing Tech University, Nanjing, China
⁴ Turku University of Applied Sciences, Turku, Finland

^* Corresponding author:

Abstract

Healthy, comfortable and intelligent indoor environment is a key objective in comprehensive well-being. This is also a main target of advanced HVAC-technology. In indoor environments, air distribution plays a major role while providing clean air to occupants. Therefore, investigating ventilation jets is an essential matter. In this study, the main objective was to improve knowledge on numerical modeling and airflow characteristics. In addition, the reliability of modeling methods were investigated. The experiments were carried out in a test room by using omnidirectional anemometers. The planar air jets were supplied below the ceiling from the opposite long-side walls. The exhaust openings were correspondingly near the floor. Isothermal and incompressible viscous airflow was simulated by using RANS, URANS, DES (SST-k-ω - LES) and SBES (SST-k-ω - LES) methods. The results show that modeling method has considerable effects on the predicted airflow field. However, the study indicates that correctly implemented numerical modeling may predict well the averaged airflow characteristics. Furthermore, the unsteady simulation allows airflows to fluctuate reasonably. In addition, SBES and DES methods were more sensitive in generating the airflow fluctuations than URANS. A recommendation is to carefully test and choose a modeling method for indoor airflows.