Engineers at Irkut Corporation were looking for a way to get better external aerodynamics data than what they were currently able to get from tube experiments. Tube experiments consist of building scale models of the aircraft and measuring values in a wind tunnel. This approach is expensive and has some inherent disadvantages.

These include low Reynolds numbers and higher airflow turbulence intensity for scale models vs. full size aircraft. There are also inaccuracies due to the scaled geometry such as radii and points where different structures such as the wings and fuselage meet. Finally, tests run in different wind tunnels can produce varied results.

To solve these issues Irkut turned to CFD as an alternative approach. As part of this the CFD tools needed to be validated for this use, the tools tested included Mentor Graphics' FloEFD and Ansys' CFX.