| Units.SI.AbsolutePressure[N + 1] | P | | Fluid pressure in node i |
| Units.SI.MassFlowRate[N] | Q | | Mass flow rate in node i |
| Units.SI.SpecificEnthalpy[N + 1] | h | | Fluid specific enthalpy in node i |
| Units.SI.SpecificEnthalpy[N] | hb | | Fluid specific enthalpy at the boundary of node i |
| Units.SI.Density[N - 1] | rho1 | | Fluid density in thermal node i |
| Units.SI.Density[N] | rho2 | | Fluid density in hydraulic node i |
| Units.SI.Density[N + 1] | rhoc | | Fluid density at the boudary of node i |
| Units.SI.Power[N - 1] | dW1 | | Thermal power exchanged on the water side for node i |
| Units.SI.Power | W1t | | Total power exchanged on the water side |
| Units.SI.Temperature[N - 1] | Tp | | Wall temperature in node i |
| Units.SI.CoefficientOfHeatTransfer[N - 1] | hc | | Fluid heat exchange coefficient in node i |
| Units.SI.ReynoldsNumber[N - 1] | Re1 | | Fluid Reynolds number in thermal node i |
| Units.SI.ReynoldsNumber[N] | Re2 | | Fluid Reynolds number in hydraulic node i |
| Real[N - 1] | Pr | | Fluid Prandtl number in node i |
| Units.SI.ThermalConductivity[N - 1] | k | | Fluid thermal conductivity in node i |
| Units.SI.DynamicViscosity[N - 1] | mu1 | | Fluid dynamic viscosity in thermal node i |
| Units.SI.DynamicViscosity[N] | mu2 | | Fluid dynamic viscosity in hydraulic node i |
| Units.SI.SpecificHeatCapacity[N - 1] | cp | | Fluid specific heat capacity |
| Units.SI.Temperature[N - 1] | T1 | | Fluid temperature in thermal node i |
| Units.SI.Temperature[N] | T2 | | Fluid temperature in hydraulic node i |
| ThermoSysPro.Units.SI.PressureDifference[N] | dpa | | Advection term for the mass balance equation in node i |
| ThermoSysPro.Units.SI.PressureDifference[N] | dpf | | Friction pressure loss in node i |
| ThermoSysPro.Units.SI.PressureDifference[N] | dpg | | Gravity pressure loss in node i |
| Real[N] | khi | | Hydraulic pressure loss coefficient in node i |
| Real[N] | lambda | | Friction pressure loss coefficient in node i |
| Units.SI.Area | Stot | | Internal heat exchange area |