| Popis: |
Considerable progress has been achieved in the field of aerodynamics during the last decades. However, the development of fluid dynamics and of its practical applications requires a deeper and deeper insight into details of the flow field. The mean velocity field can be calculated with sufficient accuracy for many classes of flows but, as it is shown later on, there are regions of industrial interest where the predictions show deviations from the experiment which are unacceptable. Furthermore, to improve the aircraft and engines efficiency, the design engineers look more and more at 3D phenomena. Unsteady aspects play an important role in specific flow domains which are of interest for particular flight conditions, especially for take off, landing and cruise flight. Complex viscous flows, separation and transition processes are of primary importance under these circumstances. The knowledge of coherent structures, such as in the slat gap of a high lift wing, become essential to understand the fluid dynamics and to improve the performance of the components of an aircraft. In these fields, computer simulations are still limited and the physical understanding has to be mainly gained from experiments. |
