When we are conducting a mesh convergence study, it is necessary to assign a theoretical convergence index. The observed convergence index is then calculated, based on the results obtained from the variables of interest. Due to different types of error, the order of convergence observed is often less than theoretical.
I got an order of convergence observed superior to theoretical. Is this a plausible result? What is the origin of this result?
With respect to the extrapolation of richarsdon, this is to calculate a value of the variable under study when the refinement of the mesh tends to zero. Does this mean that this value is the real value of the solution? or just the actual value of the numerical simulation?