With the field of CFD being over fifty years old and quite successfully applied in magneto-hydrodynamics in nuclear reactor research and rocket flights in the early 1960s when the USA ambitious project to reach the moon took off. Computers which saw rapid development in the following new generations could get solutions of CFD problems but as results poured in the things became more confusing, as while capturing one particular phenomena sharply the other got blurred. Many reasons for this came up but the present book harps on one most fundamental phenomena viz. frequency phenomena or the frequency shifted effects due to small vibrations in both theoretical and experimental data with theoretical one also bringing in the connection with grid size, time step and CFL number caused by numerical frequency shifted effects. How to solve this problem is still not fully described in this book and it is left to the imagination of the readers to do this by coming up with new methods.