Numerical investigation of transient heat and mass transfer by natural convection in a ventilated cavity: Outlet air gap located close to heat source

Abstract

A transient numerical study of heat and mass transfer by turbulent natural convection of an Air–Carbon Dioxide mixture (CO2) inside a ventilated cavity is presented. The working fluid is initially considered to be at rest at an initial temperature and concentration. The inlet air velocity is a function of the Reynolds number (5×102⩽Re⩽2×104) and constant CO2 contaminant source between 1000⩽CH⩽3000ppm is considered. The air inlet gap is located on the lower side of the right vertical wall of the cavity, whereas the air outlet is located on the right side of the upper wall. The transient governing equations of mass, momentum, heat and chemical species were solved by the finite volume method. From the results, it was found that temperatures and concentrations reached for Re<1×103 do not fulfill minimal Standards established by ISO 7730 and ASHRAE Standard 55–62, respectively. On the contrary, thermal and air quality parameters achieved for Re=1×104 satisfied all requirements in a time of 15s.