Hi Andreas. Any links or pictures to what you mean?
I need to deploy the chute with a servo based release mechanism controlled by the flight computer. The parachute will be stored inside the fuselage and eject out from a hatch. I am thinking of spring loading it. I need a parachute design that does give a slow rate of decent (1kg tot weight) of approx 0,5 m x sec^-1 max. and as good stability as possible. As little lateral drift as possible (want it to descend straight down). I also need high likelyhood of chute deployment.
Do I normally need a drogue chute for this application?
Hi, may be a good candidate. However I tend to think that the half sphere designs with a small vent at the top are the most stable. I would like to locate a shop that sells 2,5 - 3 meter parachutes. I need a low ROD.
Hi, you should remember that a slow decent and little drift don't go together. You can only have one or the other. And especially a decent rate of 0.5m/s is impossibly slow. Normal decent rates are about 3 to 5m/s. When it comes to UL rescue parachutes the decent rate can even be higher.
Perhaps you should have googled for model rocket parachutes?
Here is one I found in ten seconds flat: https://www.discountrocketry.com/parachutes---recovery/flight-84in-... .
I'm actually working on a UAV rescue system. For safe deployment at (nearly) all situations you will probably need more than just a "Jack out of the box" mechanism. I'll put a little sketch of my system into my photo album.
Hi Wendi. OK that slow descent and low drift don't go together on the same type of parachute with significantly different sizes. However, a parafoil for example, has inherent "drift" as it is designed to have lateral speed as far as I know. A spherical design with a vent should only drift from wind, mainly.
What I am after is a design that will give low ROD and move as straight down as possible (wind drift I can't control of course). I am lazy and don't want to chase the UAV far away after it has recovered. Especially in snow that is very important.
I might reconsider the ROD requirements as it is based on a square law in terms of the parachute loading (area to weight) so at some point the reduction in ROD is not worth the extra weight and volume required.
Hi JvdB. That 60" chute looks fairly bulletproof. However, I need to find a way to eject it from the fuselage without too much complexity. I am contacting aeroconsystems regarding this. Any other suggestions are welcome.