quorneng
Master member
UCDWino
Most people will agree that the maximum static thrust is obtained with a bare EDF with a bell mouth. The manufacturers certainly think so!
If you are using an inlet duct then the bell mouth technically becomes redundant although it may not be easily removable.
For a sub 250g flyer I suggest you arrange the layout so the EDF has no thrust tube whatsoever.
Best if it has no inlet duct either but if it does make sure it has an area at least the diameter of the EDF body (1.2 x FSA), is internally smooth and with the minimum of changes in shape and direction.
Not a sub 250g but an example of an EDF "at the back" with a very short thrust tube the diameter of the EDF body .
Despite its looks it is very light and a true slow flyer, as was the full size!

Most people will agree that the maximum static thrust is obtained with a bare EDF with a bell mouth. The manufacturers certainly think so!
If you are using an inlet duct then the bell mouth technically becomes redundant although it may not be easily removable.
For a sub 250g flyer I suggest you arrange the layout so the EDF has no thrust tube whatsoever.
Best if it has no inlet duct either but if it does make sure it has an area at least the diameter of the EDF body (1.2 x FSA), is internally smooth and with the minimum of changes in shape and direction.
Not a sub 250g but an example of an EDF "at the back" with a very short thrust tube the diameter of the EDF body .

Despite its looks it is very light and a true slow flyer, as was the full size!

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