OpenLB – Open Source Lattice Boltzmann Code › Forums › on OpenLB › General Topics › How and where to define a 2d airfoil? › Re: How and where to define a 2d airfoil? October 30, 2016 at 12:39 pm #2473 mathiasKeymaster Dear Klaus, basically you need to program an indicator which return true if a given coordinate (x,y) is within an object and false if not. Best Mathias