The continuity equation is essential in analyzing air flow within ducts, particularly in scenarios involving varying dimensions. When air is introduced at a constant velocity and temperature in a frictionless duct, the mass flow rate remains constant throughout, assuming negligible friction losses. For flow velocities below 0.3M, air can be treated as incompressible, utilizing standard fluid mechanics equations. However, for compressible flow, the continuity, Navier-Stokes, and energy equations are necessary to accurately describe the dynamics.
PREREQUISITESEngineers, fluid mechanics students, and professionals involved in HVAC design or any field requiring an understanding of air flow dynamics in ducts.
Perfectly answered, thank you.SteamKing said:The mass of air into a duct must equal mass of air flowing out of the duct. What happens in between depends on friction losses, velocity of the air, etc. Gas dynamics is the discipline to study, especially if compressibility effects are suspected of occurring. If the flow velocity is below about 0.3M, then the air flow can be treated as incompressible and treated with the regular equations of fluid mechanics.