Areofoil comparison

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Areofoil comparison

Postby SpaceManMat » Sat Aug 23, 2014 11:57 pm

I've been trying out RASAero. unlike RockSim and Open Rocket it has a lot of options for the aerofoil shape. I wanted to see how much difference the aerofoil shape theoretically makes. I have entered details for a L3 rocket and then altered the aerofoil to get different results.

Code: Select all

AeroFoil                                 Alt(feet)   Increase   
Square                                   12,484      
30 deg Bevel                             16,821   4,337   34.74%
20 deg Bevel                             16,945   4,461   35.73%
10 deg Bevel                             17,027   4,543   36.39%
2 deg Bevel                              17,044   4,560   36.53%
Diamond 1/2 LE/cord                      17,035   4,551   36.45%
Diamond 1/3 LE/cord                      17,054   4,570   36.61%
Diamond 1/4 LE/cord                      17,060   4,576   36.65%
Diamond 1/5 LE/cord                      17,077   4,593   36.79%
Diamond 1/5 LE/cord reducing thickness   17,120   4,636   37.14%

FYI The diamond aerofoil leading edge is being shortened above resulting in a larger trailing edge.
Also the reduced thickness fin has the same thickness at the root but the thickness is reduced towards the tip (I believe this design is theoretically ideal).

From that it can be concluded:
1. Any half decent bevel will probably get you at least 30% increase in altitude.
2. A 10 degree bevel makes for quite a good performing fin
3. A large (shallow angled) trailing edge provides superior performance

Anyone know how well these would actually perform in the real world?
QRS: 124
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Re: Areofoil comparison

Postby ogivemeahome » Mon Aug 25, 2014 6:24 am

Sailplane enthusiasts used to swear by the 'Clark Y' section - completely different purpose of course.
High speed aircraft will likely have a "NACA" profile (or something very much like it).
In general terms, the root thickness will be a %age of the chord with the tip thickness also a %age of the chord (not necessarily the same %age).
I made a rocket that used a bi-convex section - not much useable data though (crashed it! :? ).
A smooth sea never made a skilled mariner. (English Proverb)

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