Algebraic solution of transcritical carbon dioxide flow through adiabatic capillary tubes

This paper outlines an algebraic model for simulating the transcritical expansion of carbon dioxide through adiabatic capillary tubes. The model was put forward based on the analytical solution of the momentum conservation equation assuming an isenthalpic expansion process. The theoretical model predictions were compared with 66 experimental data points covering different operating conditions and tube geometries. A good agreement between the experimental and calculated mass flow rates was achieved, with more than 94% of the data points lying within an error band of ±10%.