Canted Spools?

[wwattles]

Has anyone ever tried canting a set of 3 spools into a single rocket? The outer rings of the bottom spools would be touching, but the upper plates would be cut so as to leave the spool axles (MMT's) canted like the Tres. Would it even be stable?

WW

 

[powderburner]

If I understand your description correctly, this is a configuration that goes waaay outside 'classical' aerodynamics of streamlined bodies. I don't know of anyone doing much analytical work on this family of shapes.

Regular spools apparently work due to the aero effects of shed vortices from the forward disc. They have an aft disc of the same size but I have no clue what the aero explanation is why a spool works.

If your design works, it would probably be due to the drag-rudder effect of the outer edges of the aft spools. Only thing I *can* say is that it's going to be rather draggy.

Do you have a good, solid bunker available at your flight test range?

 

[rstaff3]

There is only one sure way to find out

 

[jetra2]

No no no...there's more than one way, but there's only one FUN way!

Jason

 

[rstaff3]

I agree with the fun part, but since virtually no one (ie nobody I know of) can analyze a 'regular' spool, I assume a canted spool is also 'experimental'.

 

[wwattles]

If I ever build it, it'll start out as a 18mm CD version, which I'll launch out in the desert from the HPR pads (have to bring out a smaller launch pad to hook up to the control wires). Should be far enough out to keep it safe, but I'll call a heads-up anyway.

WW

 

[teflonrocketry1]

Originally posted by wwattles
Has anyone ever tried canting a set of 3 spools into a single rocket? The outer rings of the bottom spools would be touching, but the upper plates would be cut so as to leave the spool axles (MMT's) canted like the Tres. Would it even be stable?

WW

Haven't tried building anything like that! Due to base drag or the base vortex that forms during upward motion, the design should be stable. You might want take care in aligning the spools to prevent the model from spinning; this additional stress may cause the spools to break especially if the end plates are just CD's. Try to use a length to diameter ratio of 1.5 this gives the least amount of drag in a spool configuration. I think your design will fly stable; it seems to be analogous to a flying saucer model.

Please post more details!

Bruce S. Levison, NAR #69055