Fuel crossfeed in XML

[Herbie63 0]

Hi,I'm looking for an XML code to transfer fuel from one tank to an other - not only from left to right or vice versa.For example I have 4 tanks (1 to 4 from left to right, using left main, two center tanks and the right main). Now I want to transfer fuel from Tank 1 to tank 4. To select the source tank the isolate (18) code will work, but what do I need to select the target tankto crossfeed the fuel?Any ideas?Thanks,Herbert

[spokes2112 179]

Wow! this one came up again.. In short the only way to "TRANSFER" fuel is to make tanks 1 and 4 center tanks. Add an airfile entry to enable the center (1,4) tanks for "Concorde" logic, then use the concorde use "only" fuel transfer commands. In the end 1 & 4 can transfer, 2 and 3 cannot to anywhere.. This is short and sweet from what I can remember. For more confusing :-) information see -http://forums.avsim.net/dcboard.php?az=sho...ing_type=searchAlso I STILL (from 08-03) have the test gauges mentioned in the posts above, they are attached for your enjoyment or headaches. :-bang :-hang Regards,Romanhttp://forums.avsim.net/user_files/168835.zip

[Herbie63 0]

Thanks Roman!I'll try to understand your gauges(a lot of code, well done!),but as much as I can see it really only works with your mentioned tanks.Did you ever try out the Spirit's manual fuel transfer?It looks as if that also works with center tanks only.And what about the crossfeed_open / close events?Questions over questions...Herbert

[spokes2112 179]

HerbertYou're right!!! Questions over questions!!The Spirit of St. Louis---- Yes it uses all three center tanks.- It seems (not fully tested) that if "manual_transfer_pump=1" in the aircraft.cfg is set that one more "concorde event" occours. Also there is now a (A:) variable to monitor this.(A:Fuel Selected Transfer Mode,enum) ==4 = (>K:MANUAL_FUEL_TRANSFER) ( center 2 -> center 1 then OFF )3 = (>K:SET_FUEL_TRANSFER_AFT) ( center 1 -> center 2 ) 2 = (>K:SET_FUEL_TRANSFER_AUTO) < -- CONCORDE ONLY RELIES ON C.G.1 = (>K:SET_FUEL_TRANSFER_FORWARD) ( center 2 -> center 1 ) 0 = (>K:SET_FUEL_TRANSFER_OFF)!!! 1-3 may be out of order, didn't test fully.When variable = 4 it basically does the same as transfer fuel forward ( center 2 -> center 1 ) but automatically returns to 0 (OFF) -- TESTED.________________"And what about the crossfeed_open / close events?"Depends on the aircraft i suppose. If the aircraft had pumps based on consumption rates needed or equallized.Crossfeed left to right could be Selectors (1,2) on left tank. -OR- Selectors (1 on left, 2 on isolate) and crossfeed open. What would happen if pumps didn't match, equallize, they have constant pump rate, #2 engineout with crossfeed open, etc... then you could use transfer and some front end logic to simulate. Another one, crossfeed open, right engine out, no pumps. The left engine would use equall amounts from left and right tanks. Maybe have logic to toggle between the two tanks on left engine in an equal fashion.Again Questions over questions!!BTW what aircraft fuel system are you simulating?Roman

[Herbie63 0]

I'm working on a 4 engine cargo, having four tanks. This is all I'd like to say at the moment.I found a suitable solution using the forward / aft transfer commands, similar to what you did in your gauge. I simply placed the center tanks at the left and right, so transfering fuel changes the CoG from left to right and vv.For the two other tanks I used the aux, but the fuel gauges use calculated values of the aux AND center tanks, so it looks as if fuel was transfered from both left tanks to the right ones and vv.The rest is "simple" logic to set the tank selectors to the desired tanks. I found a nice solution for an automatic slow refuel procedure, so the only thing still missing is a fuel dump procedure. I'll do a forum search right now, as far as I remember someone found a solution for this...Thanks for your help!Herbert

[Guest gert1966]

Roman,Would you be so kind to post your test gauge once again, it seems to be deleted form the user files. I'm coding a fuek system for a Fokker 70/100 and getting nowhere at the moment, though i'm digging in the topic you mentioned...regards Gert Polkerman

[spokes2112 179]

Gert, They are attached.. BTW I took a look at them, cannot for the life of me remember how or why I did some of the coding. Keep in mind this is an early FS04 coding ( before MACROs) and written in FS02 syntax. I believe it was designed for a DC-9-50 , MD-83 type fuel system with some experiments in auto-levelling for a CRJ also.Anyway, hope they may help. Regards,Romanhttp://forums.avsim.net/user_files/173361.zip

[Guest gert1966]

Roman, Thanx for that quick reply, i will take a look at the gauge and hope i can use some of it. I'm coding the overhead panelsystems of a fokker 70/100. And a fokker has got a left main , right main and a center tank. And I also had no succes in making the crossfeed work. regards,Gert Polkerman