10 replies to this topic

[gruntguru]

http://www.autosport...t.php/id/118066

 

It seems a team may be scamming the "no accumulation device" rule by varying the pressure between the tank (incl FF Meter) and the engine. This will cause a variation in the volume of fuel in this section of the system allowing the engine to temporarily consume more than the 100 kg/hr maximum. The most effective way to do this IMO would be reducing the pressure sufficiently to form a vapor bubble.

 

If the scam uses a vapor bubble, it would be acchieved by having LOW pressure in the lines (including the fuel heater). For extra power, the fuel pressure is reduced causing a vapor bubble in the fuel heater and allowing the liquid fuel to be drawn out of the heater in addition to the 100 kg/hr coming from the tank.

 

When the engine demand is less than 100 kg/hr, the flow meter continues to see 100 kg/hr - the difference is fuel being used to re-fill the heater.

[ray b]

heater ?

what and why is there a fuel heater

 

I thought you want cool fuel as it is denser not hot fuel

or is this something like smokie's vapor/fuel tricks ?

[desmo]

Fuel flow limits are nice enough in theory, but not so much in actual practice.  A fuel quantity limit should be a much more robust regulatory approach.  The arguments I've heard against fuel quantity limits are really pretty thin and mostly rely on tenuous hypotheticals in my opinion. 

[gruntguru]

heater ? what and why is there a fuel heater

 

I thought you want cool fuel as it is denser not hot fuel

or is this something like smokie's vapor/fuel tricks ?

http://www.k20a.org/...A168EEngine.pdf

 

See page 6. Fuel temperature has an effect on combustion efficiency.

 

The current formula is an efficiency formula. The engine with the highest BSFC has the highest power.

[saudoso]

Back in the old turbo days fuel was limited by volume, so cars would start with chilled fuel to carry more. Think that's what ray b is referring to.

[gruntguru]

For airflow restricted formulae (ie 99% of racing series) cold fuel will make more power via a slight improvement in charge density.

[Wuzak]

Fuel flow limits are nice enough in theory, but not so much in actual practice.  A fuel quantity limit should be a much more robust regulatory approach.  The arguments I've heard against fuel quantity limits are really pretty thin and mostly rely on tenuous hypotheticals in my opinion. 

 

The current rules have both.

 

It is the fuel quantity limit which causes the fuel saving modes in races, which many complain about.

[MatsNorway]

I want fuel flow and im sure they will fix this if it is a loophole. Fuel saving and tire saving the last laps are boring to watch.

Edited by MatsNorway, 21 March 2015 - 12:53.

[thiscocks]

What was the reason they went with fuel flow limit rather than boost pressure limit? More accurate I assume?

[gruntguru]

To reward fuel-saving technologies. Very successful so far. We currently have F1 ICEs capable of 40%+ thermal efficiency at full power.

[imaginesix]

What was the reason they went with fuel flow limit rather than boost pressure limit? More accurate I assume?

The reason I and others prefer a fuel flow restriction is it should allow all other regulations to be relaxed in order to promote a diversity of solutions to the problem of making power. In theory anyways.