Smoke flow vis (albert and Daniel)

NOTE: Times logged

10am turned on smoke tunnel for warm up. Began 'Getting familiar suggestions'

Cleaned Window to remove dust and fingerprints

Once smokeflow started (took about 5 mins to happen, cleaned out tube), there is a noticeable effect

on the streamlines if the screwhole at the back is open or closed.

To improve smoke lines, raised the bottle of kerosene about 1.5" above the indicated liquid line mark on the side of the tunnel

However, this was not to be, the best solution is to keep the liquid level in the bottle at the indicated mark, and just wait about 10-15 mins for the smoke to really form

Appearance of streamlines gets worse at higher speeds, so will have to watch that carefully when picking a speed to run at.

There seems to be some sort of leakage in the tunnel by the right hand side light fixture.

When picking a model to test must take into account the following

Model size

Position

Flow in empty tunnel

Speed of the flow

First set of pictures taken were taken at 45 volts.

The last photo of the sphere was taken at 115 volts.

Problems and considerations

The wake of the strut (with the holes for the smoke) must be considered

At slower speeds, can see the effects of the wake, by noticing the pulses in the smoke as it flows over the foil.

The airfoil model looks slightly damaged at the trailing edge, with some imperfecdtions in the surface.

Need to measure deviation from actual shape of the foil

Airfoil model pictures were taken at 45 volts

Pictures were taken with the modified test section

The exact size of the test section must be considered

Daniel decides that taking pics of all the set up flows is too much time, could have just noted the observations, and made their own deductions

and then taken photos of maybe two pics of the set up to get the camera ready, and then just pictures of the actual test

Photos from initial setup

Flash not too good...

Flow with the wing section

45 voltds

Photos of sphere

45 volts

Phots of sphere

115 Volts

Photo of airfoil section

45 volts

Photo of airfoil section

with modified test section

Decide to go for Goal 1 in the lab manual.

Goal 1

Using NACA airfoil to see angle of attack effects on stall and separation.

Speed

45

Volts

Using modified test section as flow seems better

Photo #

Angle of attack (deg)

1

0

2

2

accuracy on angle no better than 0.5 degrees

3

4

4

6

Must adjust position of streamlines so that one stream line is hitting the leading edge of the airfoil…see pictures

5

8

6

10

7

12

8

-2

9

-4

Testing flor blockage effect at 8 degrees angle of attack

10

8

wide test section

11

4

wide test section

12

0

wide test section

13

Empty tunnel with narrow test section to see effects of covering the hole at the back (hole open)

14

Hole blocked with finger, narrow test section, empty tunnel

Albert who was moving the models and taking the pictures, concludes that the actual time taken for the test was significantly less than the set up time.

Forgot to note time started on the goal (maybe 10:35 not so sure about this).

NOTE: Missing info pointed out

End time of the measurements was 10:50.

Photos are below.

Photo 1

Photo 10

Photo 2

Photo 11

Photo 3

Photo 12

Photo 4

Photo 13

Photo 5

Photo 14

Photo 6

Sample stall location calc.

Airfoil chord (screen inch)

2.29

Distance to stall point (scn inch)

0.6

Stall at

26.20%

chord

Possible error looks about +- 5% chord.

NOTE: Photo measurement using drawing tools

Photo 7

Photo 8

Photo 9

Measring of model

(Albert, 11am)

Model looks as though trailing edge has been repaired a few times

Measurements made with caliper

To accururacy of metal ruler measurement on outside of test section, model mount is at center section, 6.75 inches downstream

of the strut trailing edge.

NOTE: Rough diagram done with drawing tools

Span = 3.90"

Need to do Reynolds numbers for report