Fuel systems for twin turbines
12-18-2007, 03:14 PM
#1
Fuel systems for twin turbines
I am working with a buddy on a twin P60 sized scale-ish design (post details when done). We want to use a single large tank (160 or so ounces )...I'm looking for feedback on the best way to set up the fuel pickups and UAT's. Here are my thoughts -
1. Two separate fuel lines/klunks going to two separate UAT's...problem might be tangling during hard manuevering.
2. One large pickup (XL Tygon) with an external "T" going to two UATs.
3. One pickup, one UAT going to a "T" to the fuel pumps.
Comments welcome...
Barry
1. Two separate fuel lines/klunks going to two separate UAT's...problem might be tangling during hard manuevering.
2. One large pickup (XL Tygon) with an external "T" going to two UATs.
3. One pickup, one UAT going to a "T" to the fuel pumps.
Comments welcome...
Barry
12-18-2007, 03:36 PM
#2
My Feedback: (1)
RE: Fuel systems for twin turbines
When I did my ME-262 I decided on two completely separate fuel systems. Each engine Had two equal size main tanks (front and rear) and it's own header tank (homemade UAT).
I didn't want to do multiple clunks in one tank because , as you said, they are likely to tangle or interfere with each other.
I didn't want to feed both engines off of the same fuel feed because I didn't think it would be a good idea to have the suction of one fuel pump being read by the other. I envisioned the ECU's constantly adjusting the pump drive voltage if one engine spooled up slight different than the other one. (This may not happen at all, but I didn't want to chance it).
I also considered separate fuel systems with a cross-feed between the tanks, but decided against that too.
In the end I decided to go with the same principle that I used when I flew twin prop models.
That is to treat each engine as it's own entity. Unless one of the shuts down, then it's best to go ahead and kill the other one too.
I didn't want to do multiple clunks in one tank because , as you said, they are likely to tangle or interfere with each other.
I didn't want to feed both engines off of the same fuel feed because I didn't think it would be a good idea to have the suction of one fuel pump being read by the other. I envisioned the ECU's constantly adjusting the pump drive voltage if one engine spooled up slight different than the other one. (This may not happen at all, but I didn't want to chance it).
I also considered separate fuel systems with a cross-feed between the tanks, but decided against that too.
In the end I decided to go with the same principle that I used when I flew twin prop models.
That is to treat each engine as it's own entity. Unless one of the shuts down, then it's best to go ahead and kill the other one too.
12-18-2007, 04:20 PM
#3
RE: Fuel systems for twin turbines
ORIGINAL: Kevin_W
I didn't want to do multiple clunks in one tank because , as you said, they are likely to tangle or interfere with each other.
I didn't want to feed both engines off of the same fuel feed because I didn't think it would be a good idea to have the suction of one fuel pump being read by the other. I envisioned the ECU's constantly adjusting the pump drive voltage if one engine spooled up slight different than the other one. (This may not happen at all, but I didn't want to chance it).
I also considered separate fuel systems with a cross-feed between the tanks, but decided against that too.
I didn't want to do multiple clunks in one tank because , as you said, they are likely to tangle or interfere with each other.
I didn't want to feed both engines off of the same fuel feed because I didn't think it would be a good idea to have the suction of one fuel pump being read by the other. I envisioned the ECU's constantly adjusting the pump drive voltage if one engine spooled up slight different than the other one. (This may not happen at all, but I didn't want to chance it).
I also considered separate fuel systems with a cross-feed between the tanks, but decided against that too.
Barry
12-18-2007, 04:43 PM
#5
RE: Fuel systems for twin turbines
Yeah....
look who's talkin' be-atch!
I'm in the middle of my 3rd long con-call (2 hrs plus per) today and needed a break! Gotta love web-ex, no one else on the conference knows what else I'm doing! (no jokes please - I'm a two hand typer).
Barry
look who's talkin' be-atch!I'm in the middle of my 3rd long con-call (2 hrs plus per) today and needed a break! Gotta love web-ex, no one else on the conference knows what else I'm doing! (no jokes please - I'm a two hand typer).
Barry
12-18-2007, 06:26 PM
#8
RE: Fuel systems for twin turbines
I'd use a single pickup with the large diameter brass tubing/tygon tubing/clunk from the main tank to two UATs via a large T, with P60s i think you won't have any problems at all with that setup. if they are long runs from the main tank to the UATs I'd recommend the T be as close to the main tank as possible for the least resistance to fuel draw.
