Cell pressure measurements

[Renegate 0]

Not sure where to post this, but rigging sounds about right.

I would imagine there has been some experimentation done with measuring pressure inside the canopy at various points in various conditions.
Question one is where to find information about this.
Question two is would mounting small (size of a dice) sensors inside and outside the canopy disturb air flow enough to make the canopy dangerous to fly?
Finally what would be the best way to temporary mount these sensors to the material of the canopy (they weight about as much as one-two quarters) ?

- It's okay to be happy to see me. Just because you're English doesn't mean you need to hide your emotions.
- I'm Irish. We let people know how we feel. Now fuck off.

[councilman24 37]

I've never seen this data available. IF a manufacturer as made these measurements it's likely proprietary data.

Not sure if anybody has bothered to use this data for canopy design development. It might be useful but might not be pratical. Contact some manufacturers and ask.

If the sensors you describe is ALL that is on the canopy, no cables or data recorder, than would be much of an issue. I can't think of a way I'd want to attach them to my canopy. For a test item that you didn't mind puting holes (stitches) in you could sew them directly if they have some kind of attaching holes or sew a pocket on to put them in. I'd forget adhesives or tape although they might work.

I'm old for my age.
Terry Urban
D-8631
FAA DPRE

[peek 21]

Quote

I would imagine there has been some experimentation done with measuring pressure inside the canopy at various points in various conditions.
Question one is where to find information about this.

We did that many years ago. We got busy doing other things so we never continued with the study.

In other words, you can ignore the statement saying, "The experiment is in progress. Full results will be released in the future."

I think it would be much easier now because there are more wireless data collection system available. Check out the wiring inside the suspension lines. Pretty crazy stuff.

Honestly, the data was so confusing to interpret that we hardly knew what to make of it. However, our research has been oriented toward parachute inflation much more than the canopy in flight.

http://www.pcprg.com/psap.htm

[hackish 8]

I believe that wires would probably be the most "dangerous" part of the experiment. You could build and probably buy some very small self contained units. At minimum you would need 2 to get the differential pressure - possibly one on the slider and N in the canopy.

I'm no aerospace engineer but I suspect the figures are probably better calculated rather than measured because speed and angle will have a huge difference and would be difficult to measure.

-Michael

[Renegate 0]

i suppose a sew pocket might work, but it would have to be a very porous material, otherwise the data readings would be inaccurate.

Quote

I think it would be much easier now because there are more wireless data collection system available. Check out the wiring inside the suspension lines. Pretty crazy stuff.

Honestly, the data was so confusing to interpret that we hardly knew what to make of it. However, our research has been oriented toward parachute inflation much more than the canopy in flight.

I think it would be easier too, and its too bad that the experiment was stopped. I personally would be more interested in conditions during actual flight, turns, wind, etc.

Quote

I believe that wires would probably be the most "dangerous" part of the experiment. You could build and probably buy some very small self contained units. At minimum you would need 2 to get the differential pressure - possibly one on the slider and N in the canopy.

If one would use a centrally operated system, multiple wireless sensors and a central data collecting interface (on the body), then you will have no problem getting actual pressure readings at any given point. Collecting differential between say top skin and bottom will be of little use unless you know exact atmospheric pressure at that altitude.

Quote

I'm no aerospace engineer but I suspect the figures are probably better calculated rather than measured because speed and angle will have a huge difference and would be difficult to measure.

We dont exactly use speed and angles in this sport. We say 180 half toggle turn not a 3 degree turn. We also dont say: reduce speed to 10 mph, we say fly half brakes. So its the actions that will need measuring and description, not physical data (except pressure of course). As for speed, that could be recorded with an accurate GPS unit. Angular speed can probably be figured out by some combination of measurements (if really needed).

- It's okay to be happy to see me. Just because you're English doesn't mean you need to hide your emotions.
- I'm Irish. We let people know how we feel. Now fuck off.