What is Adiabatic mixing?
Finding the composition, temperature and flow of streams mixed together without exchanging heat with the surroundings.
It is the first step in many processes — mixing fuel with air, diluting exhaust gas and so on.
Mixing hot and cold water gives something in between. Gases work the same way, but each species has its own heat capacity, so it is not a simple average.
Used by the Mixer block and the Gas Mixing calculator. No reactions; mass and enthalpy are conserved. Unless given, the outlet pressure is the lowest inlet pressure.
From each inlet's mass flow \dot{m}_i, mass fractions Y_{k,i} and specific enthalpy h_i:
\dot{m}_{\mathrm{out}} = \sum_i \dot{m}_i
Y_{k,\mathrm{out}} = \frac{\sum_i \dot{m}_i\, Y_{k,i}}{\dot{m}_{\mathrm{out}}}
h_{\mathrm{out}} = \frac{\sum_i \dot{m}_i\, h_i}{\dot{m}_{\mathrm{out}}}
The mixed temperature is found from h_{\mathrm{out}} and the outlet pressure.