Don Stackhouse is a full-size propeller engineer turned model manufacturer. He has compiled an impressive library of answers, including some on contra-rotating propellers. http://www.djaerotech.com/dj_askjd/askdesign.html http://www.djaerotech.com/dj_askjd/dj_questions/contra-prop.html
"The main efficiency loss is from having 2 small propellers instead of one large one to absorb the same power. You can expect a 5-20% loss of thrust.Surprising to some, it doesn't matter that much whether they are on top of each other, spaced by the fuselage or forming a 4-bladed prop. There arelots of other design features that matter as much, and a contra-rotating prop definitely has a high "cool" factor." Vriendelijke groeten ;-) Ron -- I am using the free version of SPAMfighter for private users. It has removed 357 spam emails to date. Paying users do not have this message in their emails. Get the free SPAMfighter here: http://www.spamfighter.com/len -- Liste de diffusion electron.libre archives de la listes sur : http://www.mail-archive.com/electron.libre%40ml.free.fr/ le site ftp de la liste (quand il fonctionne): ftp://electrolibriste:[EMAIL PROTECTED]:21 ou http://electrolibriste:[EMAIL PROTECTED]:12020/ftpelectronlibre/ ou en plus rapide http://electrolibriste.free.fr la liste de discussion hors sujet : mailto:[EMAIL PROTECTED] la carte mondiale des électrolibristes: http://mappemonde.net/bdd/electronlibre Pour se désinscrire : mailto:[EMAIL PROTECTED]
