Propellor question

[JoeR1]

Hello,

I have an unusual question and don't know if this is the right topic. I have to make a wind powered car/vehicle that can travel against a wind stream for a school project. the wind speed is around 10-15 m/s and i need info on the propellor design. Some say it is almost impossible to travel into a wind stream so it should be really interesting to see if it can be done. I need a powerfull desing wich will turn around 200 rpm. The max diameter is 40 cm (around 16 inch). i already have a robbe dynamic gfk 12 x 6 inch prop and i tested it. it seems to be spinning pretty fast, but i need torque. Are there any people here who know things about propellors/aerodynamics that can help me? i also don't know how many blades i should use, what is most effective?

Any help would be appreciated,

Joeri

[JetPlaneFlyer]

Some say it is almost impossible to travel into a wind stream so it should be really interesting to see if it can be done.
Well it certainly can be done, sail boats and land yachts tack into wind all the time, I've done it myself on a windsurfer!
I'll leave others with more firsthand experience to advise on what blade design and pitch would work best.

Steve

[Brandano]

You will need a weird propeller, one with a negative pitch. A standard propeller used backward might work, but the airfoil presented to the airstream won't be optimal in any case. If it's at all possible, try using a variable pitch windmill, that way you can shoot for the optimum efficiency with an empirical approach. Also, you can convert speed into torque, you only need gearing.