partial model PartialConvection "Partial model for heat convection" extends Buildings.BaseClasses.BaseIcon; parameter Modelica.SIunits.Area A "Heat transfer area"; parameter Modelica.SIunits.CoefficientOfHeatTransfer hFixed=3 "Constant convection coefficient"; Modelica.SIunits.HeatFlowRate Q_flow "Heat flow rate from solid -> fluid"; Modelica.SIunits.HeatFlux q_flow "Convective heat flux from solid -> fluid"; Modelica.SIunits.TemperatureDifference dT(start=0) "= solid.T - fluid.T"; Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a solid; Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_b fluid; parameter Modelica.SIunits.Angle til(displayUnit="deg") "Surface tilt"; protected final parameter Real cosTil=Modelica.Math.cos(til) "Cosine of window tilt"; final parameter Real sinTil=Modelica.Math.sin(til) "Sine of window tilt"; final parameter Boolean isCeiling = abs(sinTil) < 10E-10 and cosTil > 0 "Flag, true if the surface is a ceiling"; final parameter Boolean isFloor = abs(sinTil) < 10E-10 and cosTil < 0 "Flag, true if the surface is a floor"; equation dT = solid.T - fluid.T; solid.Q_flow = Q_flow; fluid.Q_flow = -Q_flow; Q_flow = A*q_flow; end PartialConvection;