Study Of Grid Error In CFD Simulation Based On Richardson Extrapolation Method

With the development of computer, CFD simulation is become an important tool of academic, the certainty factor of CFD outcomes is arousing great public concern. Combining the process of CFD simulation, all kinds of Errors in CFD simulation and methods of Estimating Errors are discussed. The Errors caused by girds are mainly studied. Using Richardson expansion, methods and guide lines to estimating Errors are built.Take NACA4412 and AGTB cascade for 2D example, Different scale Grids are simulated in each example. And the results show non-montonic variation. The modifier is more close to the real date. And take NASA Rotor 37 and NASA CC3 for 3D example,5 different scale Grids are simulated in each example also. From the characteristic-curves and the flow filed, the results are compared. Because the complexity of flow, the results show non-montonic variation very little and can't use Richardson expansion to modify the results. Finally, the results will be more close to the real date with the scale of Grid becomes small. Compared the result of every grid of each example, the impact of Grid to the result are revealed. Last using Richardson expansion, the results modified is connected with the scale of the Grid. Some useful conclusions of Grid Impact to the 2D and 3D flow CFD simulation are reached finally.