Calculation of pressure loss for an internal flow through different geometries at overall flow regime for incompressible and single-phase fluid flow considering surface roughness.
Generally this function is numerically best used for the compressible case if the pressure loss (dp) is known (out of pressures as state variable) and the mass flow rate (M_FLOW) has to be calculated. On the other hand the function dp_internalFlowOverall_DP is numerically best used for the incompressible case , where the mass flow rate (m_flow) is known (as state variable) in the used model and the corresponding pressure loss (DP) has to be calculated.
The pressure loss calculation for internal fluid flow in different geometries is further documented here.
function dp_internalFlowOverall_MFLOW extends Modelica.Icons.Function; import FD = Modelica.Fluid.Dissipation.PressureLoss.Channel; import SMOOTH = Modelica.Fluid.Dissipation.Utilities.Functions.General.Stepsmoother; input Modelica.Fluid.Dissipation.PressureLoss.Channel.dp_internalFlowOverall_IN_con IN_con "Input record for function dp_internalFlowOverall_MFLOW" annotation( Dialog(group = "Constant inputs")); input Modelica.Fluid.Dissipation.PressureLoss.Channel.dp_internalFlowOverall_IN_var IN_var "Input record for function dp_internalFlowOverall_MFLOW" annotation( Dialog(group = "Variable inputs")); input SI.Pressure dp "Pressure loss" annotation( Dialog(group = "Input")); output SI.MassFlowRate M_FLOW "Output of function dp_overall_MFLOW"; end dp_internalFlowOverall_MFLOW;