Sounds like a cool project. I think that your parawing will be doing 99% of the "gliding" though... the airspeed necessary for a gliding recovery with a parawing and with a fixed wing is going to be so drastically different that the fixed wing is going to be far below the stall point all the time, will be my guess. The parawing will provide so much drag that the airspeed will never be high enough for the fixed wing to develop any appreciable lift.
Also, the CG/CP relationships are drastically different for the regular ballistic flight regime and the gliding phase of flight... that's why rocket gliders use either pop-pods, slide-out motor/noseweight mounts as ejectable pods, swing-wings, flop wings, slide-wings, etc. to change the aerodynamic characteristics from ballistic flight to gliding flight at the correct time in the flight profile. Just hanging the rocket from the CG at parawing ejection isn't going to be enough, if indeed the rocket actually contributes anything at all to the glide itself. When you say "hang it by two strings to prevent twisting under the parawing" I take it you mean by two well-separated shroud line groups arranged perpendicular to the direction of flight... Might work... interesting. I've been toying with ideas to get smoother descent video from rocket cams using clusters of regular parachutes and different means of affixing them to the rocket to minimize swaying and ESPECIALLY spinning... (of course so far it's been mostly research and a 'thought exercise').
Just a few things to keep in mind as you move forward. Good luck with your project and be sure to post updates... this is a very fascinating idea!
Later! OL JR
PS. Hobby Lobby International (not to be confused with the "Hobby Lobby" we all hit with the 40% off coupon for rocket motors and supplies and clearance kits) had a parawing skydiver that flew under RC control a few years back when I was messing with electric park flyers... don't know if it's still available or not... Google might help there. It was pretty cool, as it was intended to be carried under a plane to altitude and released via servo, unfurling the chute and then the 'skydiver' hid the servos and receiver and battery working the parawing glider control cables to warp the chute and get the desired flight path... might be someplace to start looking at designs and stuff...
Last edited by luke strawwalker; 9th July 2012 at 10:27 PM.
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