I have a model of recuperator. it is an assemlby in whichsome parts are there. I want to define porosity to thosecomponents. I go thorugh engineering database and i define one newitem over there. I found many options over there like in resistancecalculation formula if i want to go with dependency in velocity:what is A and B stands for? wht to enter in length and area optionby default its value is 0.1m and 0.01m2 is given. any one can guideme how to define porosity to particular component and which optionis to use for engineering database?SolidworksFlow Simulation