Performance evaluation of coolant air with buoyancy in a parallelogrammic mixed displacement ventilated system

Abstract

The performance of mixed convection inside a ventilated system filled with air-CO2 mixture with uniform discrete external heat and CO2 contaminant sources is studied numerically. The lower and upper walls are inclined at different angles with horizontal axis and their respective length is considered as of the order of vertical walls. A suitable co-ordinate transformation is made to solve the coupled nonlinear governing flow equation using finite volume method based SIMPLE algorithm. Injected cold fresh air through the inlet port is considered at different locations of the left vertical wall and flush out through the outlet port along the right vertical wall. Two dimensional projection analysis is made along the middle plane for flow, temperature and concentration in terms of streamlines, isotherms and isoconcentrations with the variation of Richardson number from 0.0 to 10.0, Reynolds number Re=50,100 and inclination angle −600≤β≤600 with a fixed Prandtl number, Pr=0.71 and Schmidt number Sc=1.14 to study the CO2 contaminant effect on the ventilation effective factors such as temperature and indoor air quality. The impact of inclination angle and CO2 concentration level on average rate of heat transfer and mass transfer, average temperature, entropy generation, Bejan number, cooling efficiency and performance evaluation criterion inside the system is evaluated and found that the most effective performance is observed at lower inlet and upper outlet with β=150,Re=100 and Ri=5.0.