stu78
Feb 16, 2005, 08:28 AM
I have often wondered if there is any benifit to putting a series of ducted fans in a single duct within a model jet aircraft.
I know there is a huge difference between conventional jet engines and ducted fans, but the former tend to have several stages of compression before the combustion stage.
Now, Would it be advantageous to have two or maybe more ducted fans in a single tube?
Maybe all fans could be of the same size/speed, or a bigger slower fan at the inlet to draw in a lot of air followed by a smaller faster fan to accelerate the air further.
There are lots of possibilities, and although I studied aeronautics, engines were not my strong point :confused:
So, what would be the benifits of the following arrangements of ducted fans:
1. Two identical fans in series. (air passes through fan 1, through a sealed tube and through fan 2 to the exhaust tube.)
Versus
2. Two identical fans in Parallel. (i.e. each has its own inlet tube and exhaust tube)
3. Two different fans in series (as described in the paragrapg above). (air passes through fan 1, through a sealed tube and through fan 2 to the exhaust tube.)
I am interested to know the theoritical output in terms of static thrust and exhaust velocity. no numbers, just setup 1 should procude x time the static thrust of setup 2 etc, etc....
I hope this raises some interesting debate, and look forward to reading your views.
Stuart
I know there is a huge difference between conventional jet engines and ducted fans, but the former tend to have several stages of compression before the combustion stage.
Now, Would it be advantageous to have two or maybe more ducted fans in a single tube?
Maybe all fans could be of the same size/speed, or a bigger slower fan at the inlet to draw in a lot of air followed by a smaller faster fan to accelerate the air further.
There are lots of possibilities, and although I studied aeronautics, engines were not my strong point :confused:
So, what would be the benifits of the following arrangements of ducted fans:
1. Two identical fans in series. (air passes through fan 1, through a sealed tube and through fan 2 to the exhaust tube.)
Versus
2. Two identical fans in Parallel. (i.e. each has its own inlet tube and exhaust tube)
3. Two different fans in series (as described in the paragrapg above). (air passes through fan 1, through a sealed tube and through fan 2 to the exhaust tube.)
I am interested to know the theoritical output in terms of static thrust and exhaust velocity. no numbers, just setup 1 should procude x time the static thrust of setup 2 etc, etc....
I hope this raises some interesting debate, and look forward to reading your views.
Stuart