What types of rocket fins are best for going at high speed vertically?

Question

Well, I'm going to be captain of my rocket team next year. I'm a freshman, and I kinda got this job by default. I know all the rocket basics (equations, calculus, drag, pressure, force, etc), but i want to know what type of rocket fin will enable my rocket to go fast at a vertical line. I am using a launch lug attached to a launching rod, and can use A and B engines (as many as i want). I know not to use inverted or canted fins because this decreases velocity, so what type of fins are best for shooting fast and far in a perfectly vertical direction?

Answer 1

The best fin design is one that results in minimum drag and minimum weight. Drag is related to surface area and frontal area. Weight should be related in a similar fashion. 3 fins are better than 4, and 2 are probably not sufficient for stability.

It's been a while since I did this, but I think you want 3 fins that are small, thin, well attached (so they don't fall off during launch), placed aft of the vehicle center of mass. Some back sweep on the leading edge will reduce drag. Trailing edge must also be thin and you could reduce weight and drag further by adding a little backsweep here also. The fins should be straight and not twisted in any fashion, again to reduce drag. They should not stick out from the rocket any more than is necessary - this may require a little testing to see what will work and what will not. Be safe!

Answer 2

4 fins at 90degrees are probably better. it would be easier to keep the nose up cos you would only have to deal with 2 planes rather than 3 fins where you'd have to use vector addition. if you know what i mean.