How does one choose the number of blades and the diameter required for a turboprop propeller? I am interested in the preliminary design of a regional aircraft that uses turboprops as the propulsion method.
Following considerable research online about propeller design (disk theory, BEM...) I am rather lost on where to start.
To put it short, what parameters must be considered when designing the propeller of a turboprop device?
I am mainly interested in obtaining an idea of how many blades would be required and the diameter of the prop.
I have obtained values for the engine power requirements, and from what I can gather the main reason to have an increased number of blades is due to the requirement of absorbing the power from the engine. The latter therefore implicating an increased solidity ratio.
Is the any standard formula/theory that can provide such answers?
Thanks,
FZ
The prop diameter is chosen to provide suitable ground clearance for the desired installation. Then the reduction gearbox ratio is chosen to keep the prop tips subsonic. Then the number of prop blades is chosen to absorb full engine power. Compromises then get made to take advantage of off-the-shelf props in the market and standard gear ratios offered by the engine manufacturer.