Photo Adventures with Curiosity and Learning

The flight path from Singapore to Valencia and back. The green line is SQ 378 from Singapore to Barcelona. The red line is SQ 377 from Milan to Singapore.

It all started in Valencia about 4am, making our way to the airport for a 6:30 flight to Milan (red line). As we approached Milan, we started the circle-something routine and then to the airport.

Leaving Milan at 13:00 on SQ 377, we started our trip back. I was seated on the right - so unable to see the mountains that I saw the week before as I made my way to Valencia

Watched an El Al flight pass

Then we started our way down the runway. From time to time, when sitting before the wing, I have noticed a column of something flowing over the wing. This morning, I thought I would try to catch this - an example of laminar flow over the leading edge of the wing. I am guessing that because the velocity is high in the path of flow, the pressure is reduced causing condensation of moiture in the air. At least that is why I think I see this on take-off and landing and at low altitudes

Here is another example

The mechanism apparently is related to vortex formation and the reduced pressure inside the vortex. The core of the vortex, like a hurricane or tornado or cyclone, will be calm and probably componsed of laminar flow. As you move into the vortex, away from the core, flow is spiral in nature, higher velocity, lower pressure and perhaps adequate to force a phase change, condensation of water vapor. There are some interesting references in Wikipedia to vortex formation at the tips of aircraft wings, contrails, and the Prandtl-Glauert singularity. There are additional examples, (and better) below when we landed at Changi.

We passed the Alps - clouds and snow

then approached Lago di Garda (identified by Natalia of Flickr fame). On the right is the village Peschiera del Garda. Ok, but not as sharp as the Google satellite images

Here is Google Earth's perspective

As we continued to the south east, evening started to happen

Snow capped mountains

and progress toward evening accelerated

The streaks and colors were rather striking

Then over Turkey - east of Istanbul, the sun decided to say bye bye

Another view

and into night

About 10 hours later, Singapore began to say good morning. The clouds were like thunderheads (though this is a guess).

Good morning again

Then more what seem to be thunderheads

As we approached Changi - I had an opportunity to observe the on-again off-again nature of these tubes of laminar flow. Note where the column of whatever passes over the backward NO to the left of the front control surface. As you look at the images below, this tube moves to the left.

Another - here the tube passes of backward "step"

and off

Then on again - a little more to the left

and on and the tube is further to the left

and on

Here, the tube is much further to the left - closer to the left-most backward NO. I've got to work on better ways to improve the contrast

And finally Changi Airport and I'm home

C. Frank Starmer

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