Thread Tools
Oct 20, 2017, 06:30 AM
T. van Vuuren's Avatar

bvm .91 viofan actual thrust?

Guys I need some advice please.
I have installed a BVM .91 viofan (7 blade) into my Mirage 3 EZ I molded
The fan swept area as I worked out is 9536mm sq.
My thrust tube is 600mm long and at the rear it is 95mm diameter.
It works out to be about 81% OF fsa.

The engine screams like no banshee can but the thrust at the back of the tube and the suction at the intake does not feel remotely like my old mavric with 91 OS/ramtec setup.
I measured the static thrust on the BVM in mirage but i only get 2800 gr if my scale (standing vertical) is acurate.
For a plane that is going to weigh about 6.5kg it will NEVER fly .

Am I restricting the flow to much at 75% ?


Last edited by T. van Vuuren; Oct 21, 2017 at 12:48 AM.
Sign up now
to remove ads between posts
Oct 21, 2017, 12:49 AM
T. van Vuuren's Avatar
Here is the whole setup removed.
The FSA is 8708mm sq, the otlet @ 95mm is 7089mm sq (this is 81% FSA)
the whole thrust setup from back of fan to outle it 650mm long (cant really go shorter)
The rear of the shroud around the engine is 130mm diameter, cant chage this either.

In theory it should have worked at these measurements.....
I am out of ideas. Sugestions??


Quick Reply

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion EJF BVM Viofan conversion. How many have done one? SteveC68 Electric Ducted Fan Jet Talk 12 Oct 03, 2012 10:39 AM
Yippee! Great service at BVM for my VioFan!! imacav8r Electric Ducted Fan Jet Talk 20 Feb 02, 2008 11:56 AM
Discussion BVM VioFan Motor?? imacav8r Electric Ducted Fan Jet Talk 6 Jan 25, 2008 07:55 AM
New Product BVM Electric VioFan flybd Electric Ducted Fan Jet Talk 133 Nov 01, 2006 10:23 PM