1. Experimental techniques of the study of vortex structures caused by point injection on the leading edge of the oblique wing
Tolkachev S.N.
Gorev V.N.
Zharkova G.M.
Kovrizhina V.N.

2. Boundary layer on the oblique wing

3. Experimental setup Slip angle: 45° Angle of attack: -0.1°
Free-stream flow velocity: 4.2 m/s

4. Boundary layer velocity profiles on the attachment line

5. Velocity disturbances for two regimes of blowing
Stationary disturbance Z-direction distribution in 5 mm from the hole in Y-direction for two regimes of blowing

6. Measurement points for 3d

7. Stationary disturbances 3d
Strong blowing

8. LC thermography methodb)
a) Mechanism
b) Location on the wing c)
features:
Multiuse
Qualitative ohmic heater with uniform distribution of heat power needed
Qualitative digital camera needed to receive the right color capture
Lag attainment of stationary regime is about minutes (wing design heating)
Stationary disturbances visualization
Heat influence on the flow (destabilize)
c) Typical visualisation picture for undisturbed flow

9. Experimental setup Slip angle: 45° Angle of attack: -2.6° – 0.2°
Free-stream flow velocity: 3.4 – 9.4 m/s

10. Disturbance point injection relative to attachment line position
U∞ = 3.4 m/s Vjet = 13 m/s

11. Influence of blow velocity
U∞ = 3.4 m/s

12. Conclusion
Point injection on the leading edge of the oblique wing forms the pair of counter rotating vortices
The behaviour of the stationary disturbance depends on the blowing speed
The increase of the blowing speed leads to the decrease of the angle between the disturbance trajectory and attachment line
The weak blowing can be used for investigation of the boundary layer on the oblique wing leading edge
The strong blowing leads to complication of the flow and appearance of the strong nonlinear effects