Open Rotor at Angle-of-Attack
As part of work undertaken at the Whittle Laboratory for the European FP7 Dream Project, Turbostream was used for simulations of an Open Rotor test rig operating at an angle-of-attack.
- 40 NVIDIA Tesla M2090 GPUs
- 48 hour per revolution
- 120 million grid nodes
The unsteady flow field at a series of different angles ranging from 0 to 12 degrees was simulated. The simulations use both a fine grid (120 million grid nodes) and time step (4000 steps per revolution) in order to accurately capture the interaction of the front-rotor wake and tip vortex with the rear-rotor blade.
Figure 1 shows an axial cut of entropy function just upstream of the rear-rotor tip leading edge (the white line indicates the rear-rotor tip radius), while Figure 2 shows an unwrapped cut of entropy function at approximately mid-span. As can be seen, there is significant circumferential variation in the incoming front-rotor wake and tip vortex structure when operating at an angle-of-attack.