Numerical investigation and analysis of indoor air quality in a room based on impinging jet ventilation

Abstract

This study presents numerical investigation and analysis of carbon dioxide transport (CO2) within an isothermal three-dimensional room using impinging jet ventilation (IJV). The IJV is an effective strategy for use in buildings. The study is carried out under turbulent and transient flow regime. The URANS equations supplemented with energy and concentration equations are solved using the scStream code. We are targeting primarily the efficiency of the ventilation ɛC and the index of indoor air quality (IIAQ). The ventilation flow rate is 50 m3.h-1. Here, our ultimate aim is to analyse the behaviour of the flow and repartition of CO2 inside the room. The RNG k−ε model was adopted to handle the turbulence. CFD simulations were systematically checked through available experimental and/or numerical results. The obtained results indicated that the IJV ensures a homogeneous concentration distribution and a velocity of the ambient air less than 0.25 m.s-1. This is in agreement with the recommendations of ASHRAE Standard 55. The comparative results demonstrate that the IJV evacuates sufficiently the CO2 and ensures good air quality in an acceptable time.