Are there any generic formulas for sizing fans and motors for certain levels of airflow or thrust?
Questions:
1) For example, is there a basic aspect ratio/target RPM formula that would describe why an airplane propeller is a long and skinny while a cooling fan blade is much broader?2) How could one determine analytically if there should be a gear reduction?
3) Are there a number of specific parameters that would describe the sweep/contour of a blade?I realize that this can get very complicated. However, I need some basic info for a powerful DC fan (7"-8") needed to push a great deal of air (1000+ CFM). Currently, I am experimenting with ducted fans for RC electric airplanes. The noise level, unfortunately, is incredible.
There are a few high performance automobile radiator fans that are claiming
1000 CFM for 8" diameter blades. Any opinions?