Fuel tankage question...

[Wrench 9,848]

what I've got is an aircraft with a total fuel capacity of 464 gallons, split between 7 tanks

 

2 inner wing

2 outer wing (larger tanks)

2 tip tanks

1 fuselage tank (smallest)

 

nothing I've searched out has any information on how much which tank holds. Other than the total

 

this is what I have at the moment (and KNOW is wrong!)

 

 

[FuselageFuelCell]

SystemType=FUEL_TANK

FuelTankID=1

MaxFuelAmount=35.30

SelfHealing=TRUE

FireSuppression=TRUE

MinExtentPosition=-0.45,-0.65,-0.42

MaxExtentPosition=0.45,-1.60, 0.16

HasArmor=TRUE

ArmorMaterial=STEEL

Armor[FRONT].Thickness=2

Armor

.Thickness=2

Armor

.Thickness=2

Armor[REAR].Thickness=2

Armor[bOTTOM].Thickness=2

Armor[TOP].Thickness=2

 

[LeftWingFuelCell]

SystemType=FUEL_TANK

FuelTankID=2

MaxFuelAmount=251.7

SelfHealing=TRUE

FireSuppression=TRUE

MinExtentPosition=-3.30,-0.70, 0.06

MaxExtentPosition=-5.30,-1.70, 0.17

HasArmor=TRUE

ArmorMaterial=STEEL

Armor[FRONT].Thickness=2

Armor

.Thickness=2

Armor

.Thickness=2

Armor[REAR].Thickness=2

Armor[bOTTOM].Thickness=2

Armor[TOP].Thickness=2

 

[RightWingFuelCell]

SystemType=FUEL_TANK

FuelTankID=2

MaxFuelAmount=251.7

SelfHealing=TRUE

FireSuppression=TRUE

MinExtentPosition=3.30,-0.70, 0.06

MaxExtentPosition=5.30,-1.70, 0.17

HasArmor=TRUE

ArmorMaterial=STEEL

Armor[FRONT].Thickness=2

Armor

.Thickness=2

Armor

.Thickness=2

Armor[REAR].Thickness=2

Armor[bOTTOM].Thickness=2

Armor[TOP].Thickness=2

 

[innerLeftWingFuelCell]

SystemType=FUEL_TANK

FuelTankID=2

MaxFuelAmount=81.62

SelfHealing=TRUE

FireSuppression=TRUE

MinExtentPosition=-0.90,-0.00, 0.04

MaxExtentPosition=-1.60,-2.00, 0.15

HasArmor=TRUE

ArmorMaterial=STEEL

Armor[FRONT].Thickness=2

Armor

.Thickness=2

Armor

.Thickness=2

Armor[REAR].Thickness=2

Armor[bOTTOM].Thickness=2

Armor[TOP].Thickness=2

 

[innerRightWingFuelCell]

SystemType=FUEL_TANK

FuelTankID=2

MaxFuelAmount=81.62

SelfHealing=TRUE

FireSuppression=TRUE

MinExtentPosition=0.90,-0.00, 0.04

MaxExtentPosition=1.60,-2.00, 0.15

HasArmor=TRUE

ArmorMaterial=STEEL

Armor[FRONT].Thickness=2

Armor

.Thickness=2

Armor

.Thickness=2

Armor[REAR].Thickness=2

Armor[bOTTOM].Thickness=2

Armor[TOP].Thickness=2

 

[LeftWingTipTank]

SystemType=FUEL_TANK

FuelTankID=3

MaxFuelAmount=250.0

SelfHealing=FALSE

FireSuppression=FALSE

MinExtentPosition=-6.10,-2.76,-0.02

MaxExtentPosition=-6.68,0.03,0.49

HasArmor=TRUE

ArmorMaterial=ALUMINIUM

Armor[FRONT].Thickness=2

Armor

.Thickness=2

Armor

.Thickness=2

Armor[REAR].Thickness=2

Armor[bOTTOM].Thickness=2

Armor[TOP].Thickness=2

 

[RightWingTipTank]

SystemType=FUEL_TANK

FuelTankID=3

MaxFuelAmount=250.0

SelfHealing=FALSE

FireSuppression=FALSE

MinExtentPosition=6.10,-2.76,-0.02

MaxExtentPosition=6.68,0.03,0.49

HasArmor=TRUE

ArmorMaterial=ALUMINIUM

Armor[FRONT].Thickness=2

Armor

.Thickness=2

Armor

.Thickness=2

Armor[REAR].Thickness=2

Armor[bOTTOM].Thickness=2

Armor[TOP].Thickness=2

 

what my question(s) is/are:

 

what (again!) is the unit used for the fuel mass? kgs? liters? lbs?

 

I can assume (oh! that damn word again!!), that I can make the 6 "main" tanks pretty much all the same capacity, with the fueselage tank having the least

 

i hate math...

[+Trotski 936]

isn't it generally in lbs mate ?

[+Trotski 936]

I would say that generally 200 gallon tip tanks is about the norm, which is about 1340 lbs and looking at the way you have distributed it, and comparing to a Sabre, you have the ratios not far off, I reckon those amounts are most likely in Gallons .

[Fubar512 1,350]

Kevin,

 

Weights are in kilograms.  464 gallons of jet fuel@6.8 lbs per gallon = 3155 lbs, which in turn translates to 1431.17 kg.  Summing up the values of all those tanks comes out to 1201.94, which is simply bad math (or using the wrong weight value for JP-5, which comes out to 6.8 lbs per gallon at 59 degrees Fahrenheit).

 

If we convert gallons directly to liters, we arrive at 1756.43, so it's not a value in liters.  

[Tzareff 6]

I think third wire use kilograms for fuel capacity measure. So if you have max internal fuel for the aircraft in galons you must convert them in liters then mulyiply by 0.8 to get the exact fuel weight in kilograms ... or simply use that tble:

 

http://www.streamline-ops.com/en/info/fuel_weight_conversion_tables/

 

Its definetly kilograms because in the MiG-21MF original data ini is stated that internal fuel tnks have capcity of  2198?? wich is the max fuel of MiG-21MF in kg 2200kg acoring to this site:

 

http://www.airwar.ru/enc/fighter/mig21mf.html

[charlielima 328]

Weapon weights are metric.

CL

[+KnightWolf45 1,147]

SF his all in metric sistem sizes weight speeds etc!

[+Cliff7600 1,148]

I've already done things like that. Here's my way of dealing with it :

 

If you know where the tank is located in the aircraft, define some min / max extent values (with ruler tools or LOD viewer)

Then... take the dimension of the length, width and height of the box.

multiply the three values (in meters) and multiply by 1000 => you have the weight for the same amount of water.

As it's not water, multiply by the coefficient that fit the best for avgas or jetfuel (something like 0.78 / 0.8) and you have your weight in kg.

 

Do that for all the tanks and edit the values to have the right amount of fuel (because tanks are not boxes all the time, they're cylinder sometimes, and not perfect cylinders)

 

exemple :

 

MinExtentPosition=-0.56,3.09,-0.66

MaxExtentPosition=0.56,4.03,-0.02

 

0.56 + 0.56 = 1.12 (-0.56 and 0.56 are the same length each side of zero)

4.03 - 3.09 = 0.94 (4.03 and 3.09 are both +)

0.66 - 0.02 = 0.64 (-0.66 and -0.02 are both -)

 

1.12 x 0.94 x 0.64 = 0.673792

0.673792 x 1000 = 673.792 Liter of water

 

673.792 x 0.78 = 525.55776 kg of fuel (0.78) so 525.56 kg

 

It may not give the right amount of fuel but it gaves a proportionality between several tanks, to decrease or increase the finale values.

 

Sorry for the maths... :^l

[+russouk2004 6,958]

research real life tanks....then its added to the tanks ini file in weapons folder in the tanks data.ini

this is the Tank370_F16_PAK

 

[WeaponData001]
TypeName=Tank370_F16_PAK
FullName=370-gal Drop Tank PAK
ModelName=Tank370_F16_PAK
Mass=1500.000000
Diameter=0.580000
Length=4.300000
SubsonicDragCoeff=0.147000
SupersonicDragCoeff=0.279000
AttachmentType=
SpecificStationCode=
NationName=
StartYear=0
EndYear=0
Availability=0
BaseQuantity=0
Exported=FALSE
ExportStartYear=0
ExportEndYear=0
ExportAvailability=0
WeaponDataType=5
MaxFuelAmount=1410.000000
Asymmetrical=FALSE
 

[KJakker 901]

I was playing around with the B-52's fuel capacity and found this data for fuel weight. I don't know how accurate it is so you might want to cross check it.

 

Jet A is the same as JP-8 and weights 6.76 LBS/gallon 

Jet B is the same as JP-4 6.36 LBS/gallon 

JP-5 was for carrier based jet fuels (low flash for safety) and is 6.8 LBS/gallon.

 

Using the pounds per gallon of  JP-4 listed above I get the weight below. If you need avgas for WWII prop planes that is a different LBS/gallon ratio than any jet fuel.

 

464 x 6.36 = 2951.04 lbs

 

The number of pounds above converted to kilograms gives me this.

 

1338.5692275648 kg

 

If the numbers you entered for each fuel tank are gallons then converted to Pound and Kilograms I get the numbers below. 

 

Gallons to Pounds

 

[FuselageFuelCell]

SystemType=FUEL_TANK

FuelTankID=1

MaxFuelAmount=224.508

 

[LeftWingFuelCell]

SystemType=FUEL_TANK

FuelTankID=2

MaxFuelAmount=1600.812

 

[RightWingFuelCell]

SystemType=FUEL_TANK

FuelTankID=2

MaxFuelAmount=1600.812

 

[innerLeftWingFuelCell]

SystemType=FUEL_TANK

FuelTankID=2

MaxFuelAmount=519.1032

 

[innerRightWingFuelCell]

SystemType=FUEL_TANK

FuelTankID=2

MaxFuelAmount=519.1032

 

[LeftWingTipTank]

SystemType=FUEL_TANK

FuelTankID=3

MaxFuelAmount=1590.0

 

[RightWingTipTank]

SystemType=FUEL_TANK

FuelTankID=3

MaxFuelAmount=1590.0

 

Total Fuel Amount in Pounds = 7644.3384

 

Gallons to Kilograms

 

[FuselageFuelCell]

SystemType=FUEL_TANK

FuelTankID=1

MaxFuelAmount=101.835116

 

[LeftWingFuelCell]

SystemType=FUEL_TANK

FuelTankID=2

MaxFuelAmount=726.116109

 

[RightWingFuelCell]

SystemType=FUEL_TANK

FuelTankID=2

MaxFuelAmount=726.116109

 

[innerLeftWingFuelCell]

SystemType=FUEL_TANK

FuelTankID=2

MaxFuelAmount=235.461251

 

[innerRightWingFuelCell]

SystemType=FUEL_TANK

FuelTankID=2

MaxFuelAmount=235.461251

 

[LeftWingTipTank]

SystemType=FUEL_TANK

FuelTankID=3

MaxFuelAmount=721.211868

 

[RightWingTipTank]

SystemType=FUEL_TANK

FuelTankID=3

MaxFuelAmount=721.211868

 

Total Fuel Amount in Kilograms = 3467.413572

Edited March 20, 2016 by KJakker