I credit Rockin Robbins on wattflyer.com for posting this. Great study of various propeller types.
http://www.ae.illinois.edu/m-selig/pubs/BrandtSelig-2011-AIAA-2011-1255-LRN-Propellers.pdf
http://www.ae.illinois.edu/m-selig/pubs/BrandtSelig-2011-AIAA-2011-1255-LRN-Propellers.pdf