Oil flow vis (George and Marie)

Began at 10am

Flow conditions (measured by Marie)

Pressure

941.1

mBar

(note change from sheet 1)

Temperature

18.5

291.5

Getting Familiar

Took two pictures of tunnel:

Flash works well.

Using Digital manometer (Dwyer Series 475) to measure flow speed.

Turned on tunnel, flow temperature started rising - maybe should check this during the oil-flow vis.

No sign of drift in Pito

Found max speed corresponding to a pressure of

580

Pascals (according to manometer)

(Error +-10

Flow temp now

20.2

293.2

Atmos press

941.1

mBar

Density

1.118381

kg/m^3



					NOTE: Formulae programmed right into log book

Viscosity

1.81E-05

m^2/s

So max flow speed must be

32.2058

m/s

by Bernoulli

Reynolds number for airfoil (0.203m chord) is at max

360605.4

based on nominal chordlength

Accuracy on inclinometer (Polycast #36) looks to be about +- 0.5 degrees

Model location

Model shaft is located 17.75" from test section entrance, 44.5" from floor (bottom of test section entrance is 26.625 from floor).

Model appears to be accurately centered spanwise (to about 0.25")

Shaft center (center of rotation to angle of attack) located 3.2" from leading edge (40% chord - chord= 8")

Pitot static

Probe tip centered 8.313" from top center of test section entrance

Initial batch of oil -

Used 30ml kerosine

10 ml TiO2

2 ml Oleic acid

Didn't mix much (George mixed)

Spread oil on airfoil at 22 degrees AoA. Turned tunnel on to full speed

Pitot Static

505

(less than before, blockage?)

Temp

20.5

Flow vis looks neat but too much oil (big puddles formed.)

Sample pictures on right.

Marie suggested that should have ruler in picture when taking photos -

could also get scale from chordlength though.

Must use less oil during test.

Looked at appendix 2 from the ma

Sounds like spanwise uniformity c

Perhaps this explains why the airfo

even symmetric across the span

More info on tunnel at

http://www.a

Decided to go for goal 2. Effects of Reynolds number on 3D stall pattern

Began on goal 2 at 10:50am.

Decided to choose 22 degrees as angle of attack for study.

Will run at 3 speeds

10, 20 and 30m/s

Using bernoulli, these will be Pitot-static pressures of about

Speed

m/s

Pitot Stat

55.9190668

223.6763

503.2716

(about)

1st test - high speed

Oil mixture as above

Temp.

20.7

293.7

Atm. Pres

940.4

mBar

Pitot Stat.

220

Density

1.11564694

kg/m^3

Viscosity

1.8158E-05

m^2/s

(actually programmed this in to s

Velocity

19.8592549

m/s

222020.958

Photos overlap about as shown. Still too much Oil!!

Can see leading ege separation, and two big foci around stall region to right han

wing.

2nd Test, mid speed

Oil mixture as above

Temp.

20.6

293.6

Atm. Pres

940.4

mBar

Pitot Stat.

500

Density

1.11602693

kg/m^3

Viscosity

1.8153E-05

m^2/s

(actually programmed this in to save time)

Velocity

29.9338559

m/s

334740.333

3rd Test, low speed

Oil mixture as above

Temp.

20.6

293.6

Atm. Pres

940.4

mBar

Pitot Stat.

Density

1.11602693

kg/m^3

Viscosity

1.8153E-05

m^2/s

(actually programmed this in to save time)

Velocity

10.3693919

m/s

115957.453

Took thinner mixture from top of mixing dish (some of the TiO2 had settled out)

Oil was too thick, never really moved near trailing edge.

Decided to stick with this ad skip the sero angle of attack stuff as ran

out of time


	Original brush strokes