Calculation of the log mean temperature difference for a heat exchanger
function logMean extends Modelica.Icons.Function; input Real dTx "Temperature difference 1"; input Real dTy "Temperature difference 2"; input Real small_dT = 1.0 "small x or y"; input Real tol = 0.05 "small difference x-y"; output Real lmTd "Logarithmic mean"; end logMean;