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Andrew Wilson

A320-X: Fuel System

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Andrew Wilson

I thought some of you might be interested in a few more details about our A320-X, and write a little about the fuel system we have modeled.

I've mentioned before that we've designed a fluid dynamics simulation to model aircraft fuel, bleed air and hydraulics - it is actually adapted from a similar model we use to simulate electric current throughout the aircraft. This system allows us to simulate, for example, an accurate model of fuel pressure and temperature propagation through the aircraft.

What we're also doing is simulating our fuel tanks in 3 dimensions. Most aircraft products for MSFS only simulate a fuel tank using the default coordinate system that FSX provides. Our fuel tanks on the A320-X are more than just a point in space, we actually calculate where the fuel is inside the tank - how it reacts to pitch, roll and acceleration.

Why have we done this? Well - the A320 fuel system comprises of around 30 fuel sensors (all of which are modeled), and their resistance is measured by the Fuel Level Sensing Control Units. From this resistance the FLSCUs can deduce if the sensor is wet or dry and through a series of logic gates, controls various valves in the fuel system. Such valves include the wing tank transfer valves, that latch open to allow the transfer of fuel from the outer wing tanks, to the inner wing tanks where the main fuel pumps feed the engines. The logic gates in the FLSCUs command the transfer valves to open if any one of the inner wing tank low level sensors become dry.

Now here's where it gets interesting and where our 3D fuel tanks come into play: two of the fuel low level sensors are situated on the rear spar of the wing inside the inner wing tank. If the aircraft pitches down, for example at top of descent and the fuel level in the inner wing tank is within a few hundred kilos of the low level, there is a good chance that the sensors on the rear spar will become dry and the FLSCUs will command the wing transfer valves to latch open early.

This isn't documented in the FCOM or AMM; but it occurs quite often on the real aircraft. And because we have modeled the Flight Sim Labs A320-X in such intricate detail, you can expect to see the same thing happen in our simulation.

As Lefteris stated in his presentation in Munich last month - we are all avid simmers at heart here at FSL, and we're very excited about our upcoming A320-X, which is packed full of features just like the ones I've described here. We're sure as we release more details about the A320-X, you guys will be just as excited as we are!

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Marcel Semelka

Just one fact: You guys are crazy....

... but awesome !!!

So will be so many details in this aircraft, wow.

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Heimue

Actually, I have to agree to Airbusflyer ... you guys are totally crazy!

but keep that going!

seems we have a interesting time once the bus is available :)

Thomas

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Chris Howard

Nah their not crazy guys, they are totally bonkers lol.

Seriously tho, that is what you call some serious attention to detail and devolopment skills, hats off to you guys at FSL, we cant wait!!

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Lulu Daniel Van Grijs

WOW! Amazing! It will be a new level of flight simulation!

Can't wait!!!

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Sameer Mankame

Wow!! I am really happy to hear the detailed simulation implemented in FSL A320.

Cant wait to take her for a spin

Sameer Mankame

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Aerlingus231

Very nice guys, keep up the good work...

Ró.

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Arunit Mukherjee

A big thanks to all the simulation engineers. It will really act as a Level-D alternate for all my recurrency checks practise. I just hope FSLabs simulates all of the functions of FMS 2 CDU, eg. RAD IN, RAD OUT, ETP, closest airports, Stored waypoints, FIX Info(V imp), most imp :SEC FLPLN.

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StephT

Guys,

I have a new slogan for the upcoming bus : "More real than the real one" !

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A320DRIVER

Congratulations for the effort. As a driver of A320 fleet, I think this model will be the better one available for the flight sim.

bye

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smokeyupahead

It gets better and better...!

David DD

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Fernando

Congratulations, that is absolutely impressive! The level of detail of this airplane is awesome! Can't wait to fly this bird.

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Philippe Gleize

Guys,

I have a new slogan for the upcoming bus : "More real than the real one" !

Not that bad. I have another one : "Fly by Numbers" !

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Karl Brooker

Hi Andrew, I just came across a video of a Cyprus Air A320 that starts it's descent and gets ECAM Warnings about Fuel Level Low...I believe this is the same little "quirk" that you mention in your original post. (2:10 into the video for the more impatient viewers :P )

[media=]

[/media]

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Andrew Wilson

Yes - good find! That's an EIS1 aircraft too - the old ones do tend to hide more fuel in the descent. The newer, EIS2 systems (upon which our A320-X is modelled) are a little more accurate, but you'll still see a little fuel disappear from time to time.

There are so many of these features on the A320 that we've simulated - most only real world pilots will appreciate at first, but over time I believe our customers of the A320-X will be able to recognise them as features of the A320 fleet :)

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Andrew Wilson

Well, we have wired our A320-X in the same manner as the real aircraft - so the results should be (and are) very similar.

In fact, and just to give you an idea of how complex this simulation is - we have around 60,000 connections between the various systems, mirrored on the real aircraft. Collectively, these connections process well over one million pieces of data, every second.

When we say our A320 is "fully simulated", we mean it.

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Lefteris Kalamaras

The worst part of it is when we have to debug something and the wiring manual is wrong... (yes - that happened already... twice!)

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Mark Richards

Fantastic work team, I'm so looking forward to the FSLabs A320.

What worries me is that as a Boeing fan, after flying this given the level you're going to, I will probably never want to fly the Boeing again.

Keep up the good work.

Mark

Sent from my iPad using Tapatalk HD.

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Charan Kumar

Would I be able to fly this without having to attend Airbus school?? :D :D :D

Sounds Amazing....Thanks for letting us desktop aviators get close to the real thing.

As Real as it Gets

Cheers!!

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John Barnes

Fantastic work team, I'm so looking forward to the FSLabs A320.

What worries me is that as a Boeing fan, after flying this given the level you're going to, I will probably never want to fly the Boeing again.

Keep up the good work.

Mark

Sent from my iPad using Tapatalk HD.

here is me thinking you were an EJet god Mark. :o

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Mark Richards
here is me thinking you were an EJet god Mark. :o

Barnsey, I posted that to make sure you were still awake... Ok, a Boeing AND an E-Jet fan...

I'm actually a fan of decent simulations so can't wait for the FSLabs A320, not to mention these forums are a MUCH friendly place to visit that the alternate ones, which is testament to the quality of the product and the users this addon is targeting as their market.

Sent from my iPad using Tapatalk HD.

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Remy

Well, we have wired our A320-X in the same manner as the real aircraft - so the results should be (and are) very similar.

In fact, and just to give you an idea of how complex this simulation is - we have around 60,000 connections between the various systems, mirrored on the real aircraft. Collectively, these connections process well over one million pieces of data, every second.

When we say our A320 is "fully simulated", we mean it.

Well Actually after reading this post, you've got all my attention and Money :). no matter what it will cost I'm getting it for sure :) FSLabs where others don't dare -- should be your motto :)

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TMEforAbus

I thought some of you might be interested in a few more details about our A320-X, and write a little about the fuel system we have modeled.

I've mentioned before that we've designed a fluid dynamics simulation to model aircraft fuel, bleed air and hydraulics - it is actually adapted from a similar model we use to simulate electric current throughout the aircraft. This system allows us to simulate, for example, an accurate model of fuel pressure and temperature propagation through the aircraft.

What we're also doing is simulating our fuel tanks in 3 dimensions. Most aircraft products for MSFS only simulate a fuel tank using the default coordinate system that FSX provides. Our fuel tanks on the A320-X are more than just a point in space, we actually calculate where the fuel is inside the tank - how it reacts to pitch, roll and acceleration.

Why have we done this? Well - the A320 fuel system comprises of around 30 fuel sensors (all of which are modeled), and their resistance is measured by the Fuel Level Sensing Control Units. From this resistance the FLSCUs can deduce if the sensor is wet or dry and through a series of logic gates, controls various valves in the fuel system. Such valves include the wing tank transfer valves, that latch open to allow the transfer of fuel from the outer wing tanks, to the inner wing tanks where the main fuel pumps feed the engines. The logic gates in the FLSCUs command the transfer valves to open if any one of the inner wing tank low level sensors become dry.

Now here's where it gets interesting and where our 3D fuel tanks come into play: two of the fuel low level sensors are situated on the rear spar of the wing inside the inner wing tank. If the aircraft pitches down, for example at top of descent and the fuel level in the inner wing tank is within a few hundred kilos of the low level, there is a good chance that the sensors on the rear spar will become dry and the FLSCUs will command the wing transfer valves to latch open early.

This isn't documented in the FCOM or AMM; but it occurs quite often on the real aircraft. And because we have modeled the Flight Sim Labs A320-X in such intricate detail, you can expect to see the same thing happen in our simulation.

As Lefteris stated in his presentation in Munich last month - we are all avid simmers at heart here at FSL, and we're very excited about our upcoming A320-X, which is packed full of features just like the ones I've described here. We're sure as we release more details about the A320-X, you guys will be just as excited as we are!

At the rate you guys are performing, you will be the new "Janes" of flight simulation. Details, details...I love it.

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lufthans

Looks very promising! I remember the day the virtual "buspilots" were going crazy about the Airsimmer thing. Their release looked good as a work in progress, but to this day, the advanced version is nowhere to be seen and I presume there were financing issues. Now with the info I gathered about the FSL project, the community puts its trust in you ;) . Do please post every possible sneak-peek.

Cheers!

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IgorSulim

So, if it needs to pay 1500 $ for this product, I'll do this. Amazing!:)

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capt.balu

Cool- even such little details are simulated!! But does this ECAM message occurs every flight or is it connected to a random generator so that this message will occur, let's say on 25% of flights?

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Peter Fabian

Judging from previous experiences, definitely not random... I mean, it is not random in real aircraft... I suppose it will depend on pitch, acceleration rate in length axis... etc. that kind of stuff that would move the fuel around in tanks in real aircraft...

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Karl Brooker

Cool- even such little details are simulated!! But does this ECAM message occurs every flight or is it connected to a random generator so that this message will occur, let's say on 25% of flights?

Neither. It will happen when the conditions needed for the 'phenomenon' to occur are met. :)

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christopherwallace1983

I have already fallen in love with FSL320. The quality, as mentioned before, both in terms of product and in service, is outstanding. Fantastic work, and looking forward to purchasing this remarkable simulation!

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Marc Aussant

60 000 ... sure impressive , but hopefully effective ...:))))) Just a joke .....

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Lukas Leccese

I'd like to have that question answered as well.

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Arto E.P. Karhu

According to the data I've got at hand, the FADEC should stop the circulation through the IDG automatically should the fuel temp get too high, a bit above 50 °C. The fuel in the wing tanks should not reach higher temperatures by IDG induced warming alone, however, I'd figure in places like Riyadh the Sun can heat it further even if the circulation is cut off. However, eventually, when the IDG runs without cooling flow and oil temp gets up to around 185 °C, an IDG overheat signal is generated and IDG FAULT shown, prompting the crew to disconnect the IDG. That's likely not too fun situation to end up in.

-Esa

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Lukas Leccese

So, does that mean that you are screwed either way in desert like conditions?

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Andrew Wilson

In this scenario it is advised to select the GALLEY to OFF, reducing the load on the IDG,

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koen meier

A video by pilots eye about this problem where they ultimatly need to return to Zürich.

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Arto E.P. Karhu

Edit: disregard! :) Need to check something out!

-Esa

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LH458

Nice to see that such faults are simulated. But why is the ECAM asking to turn GEN 1 off? I thought the aim of the procedure was to cool down the IDG 2, since the fuel on the right side is to warm. Turning GEN 1 off would only reduce the load on IDG 1 thus not effecting the temperature of the fuel returned to the RH Inner Tank?

 

Also if you would follow the ECAM Procedure until the very end (IF TEMP ABV 57 DEG C), it would call for both GENs to be selected off. This would leave only the APU to supply electrical power. That can't be right.

Unbenannt.JPG

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Mikaël Taïeb

the answer is highlighted in yellow  : if opposite GEN available (in this case :gen 1),  the ecam will ask you IDG 2: OFF. 

if it's not available because you switched gen 1 off earlier,  then ecam will not ask you anymore to turn IDG 2 off. (ecam will refresh to remove that item I believe ) 

To your first question why is it requesting gen 1 off?  I'm unable to answer...  maybe there is another situation we can't see on that screenshot?? 

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LH458

Thank you for the clearification on that. I can see how this would work.

But concerning the GEN 1 OFF, I think this is a bug since the action is listet under the R INNER TK HI TEMP Warning, so it belongs to that failure but it defenetly makes no sense there.

Maybe the Devs can have a look at it. Sadly I am not able to test it myself at this point.

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