Question

Wind Tunnel Experiment:

1. Using the manometer measurements, determine the two speeds with which the wind tunnel was operated. (1 mark)

2. Discuss how changes in Reynolds Number affect the flow separation and provide a source that supports your suggestion. (2 mark)

3. Discuss how the angle which separated flow is achieved varies for each tuft depending on its location and explain why this is occurring.

4. What flow structure can be identified at the tip of the wing and describe how the tufts react differently at this location?

5. Calculate the Static Pressure Coefficient over the wing using the static pressure values provided. (1 Mark)

CFD Analysis:

6. Describe your CFD methodology, meshing considerations and solution setup. Justify the decisions you have made for these parameters using results that you have obtained or by citing suitable references.

7. Determine the lift and drag for the wing at both angles of attack using the CFD model. (1 Mark)

8. Compare the flow fields for both angles of attack, describe and locate the key flow features such as those in the wake region and separation points if they exist.

9. Calculate the Static Pressure Coefficient over the wing and the velocity field in the wake from your CFD results and plot these over the corresponding experimental results provided. (2 Mark)

Discussion and Conclusion:

10. Include a detailed discussion comparing your CFD analysis and results with the wind tunnel results plotted in question 9. Identify any sources of error between the experiment and the CFD and determine how this may have affected the comparison between the two.

11. If you were asked to repeat the CFD analysis, what would you change in the setup of the model to better predict the flow features viewed in the wind tunnel.

	Manometer (off)	Manometer (low)		Manometer (high)
Length (mm)	255	330		403
Height (mm)	52.14649322	67.48369711		82.41190889
Gradient (°)	11.8	11.8		11.8
Manometer reading at low speed:
	Tuft 1(°)	Tuft 2(°)	Tuft 3(°)	Tuft 4(°)	Tuft 5(°)
1	-	16.8	14.1	15.1	12	Trailing end
2	-	18.3	16.3	17.5	14.2
3	-	21.2	19.2	20.2	24.7	Leading Edge
16.3°-Vortex becomes parallel to the wind tunnel
Manometer reading at high speed:
	Tuft 1	Tuft 2	Tuft 3	Tuft 4	Tuft 5
1	-	16.6	13.7	15.2	12.1	Trailing end
2	14.2	17.8	15.7	16.2	13.7
3	-	22.1	16.7	19.8	22.1	Leading Edge
9°-Vortex becomes parallel to the wind tunnel

Answer 1