Adiabatic Mixing of Two Air Streams
Adiabatic Mixing of Two Air Streams
When two air streams merge (e.g. fresh and recirculated air), the mixed temperature is the mass-weighted average of the two.
The mixed temperature is T = (ṁ_1·T_1 + ṁ_2·T_2)/(ṁ_1 + ṁ_2). where ṁ_1, T_1 and ṁ_2, T_2 are the two streams’ mass flows and temperatures.
Inputs
m_1 := 1.5 kg/s=1.5 kg/s
T_1 := 303 K=303 K
m_2 := 0.5 kg/s=0.5 kg/s
T_2 := 288 K=288 K
Take the mass-weighted average temperature.
T := (m_1·T_1 + m_2·T_2)/(m_1 + m_2)=299.25 K
Results
The mixed temperature sits closer to the larger stream. The same balance applies to blending any two flows of the same fluid.
Assumptions & limitations
- Adiabatic mixing (no heat loss).
- Same fluid and pressure.
- Steady flow.