Effect of Size of Heated Obstruction within Room on Three Dimensional Air Flow Characteristics

Abstract

Problem statement: This study reported a numerical investigation of three-dimensional turbulent buoyant recirculating flow within a room with heated obstruction. Approach: The study involved the solution of partial differential equations for the conservation of mass, momentum, energy, concentration, turbulent energy and its dissipation rate. These equations were solved together with algebraic expressions for the turbulent viscosity and the heat diffusivity, using k-ε turbulence model. Results: The present study demonstrated the flow behavior, thermal distribution and CO₂ concentration inside the room in the presence of heat flux obstruction with respect to three sizes of obstruction. Conclusion: The energy usage coefficient (efficiency of ventilation) increases with decrease in size of obstruction. Concentration of CO₂ is very often used as an indicator for the control of air flow rate to the building. For the largest size of obstruction, the concentration of CO₂ is maximum above the obstruction and reduces with the reduction in the size of the obstruction.