Hello! I am trying t solution Navier-Stokes equation and I cannot find something about Laplacian. I would like to solution Laplace’a equation for each component.I am trying to transform cylindrical coordinate. I would like to search equation for covariant derivative. For divergence of a contravariant tensor I found: Aj;k=1/gkk(dAj/dxk)-ri;jkAi where r is christoffel symbol I do not know what I have to change that obtain the same for Laplace’a equation? If Christoffel symbols do not change? I will be grateful for any directions and instructions.