Many thanks!
Fuel consumption
Fuel consumption
Can someone quickly run through how fuel consumption is worked out? I'm wondering how the Injector Consumption Scaling table is used?
Many thanks!
Many thanks!
-
pat
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Re: Fuel consumption
Fuel consumption is calculated based on the open time of injectors 
The injector consumption scaling sets the nominal flow rate of one fuel injector, in ml/sec. When a fuel pulse is scheduled a theoretical fuel delivery is calculated based on this flow rate and the injection time; this happens on a per cylinder basis. Things that are not taken into consideration are factors like the battery adder (since no fuel is being delivered in this time) and relative fuel pressure multiplier (because we are still delivering the same amount of fuel as we would have done had the pressure been nominal and the final injection pulse not been modified for a non-nominal fuel pressure). With regard to the secondary injectors, their pulse width is modified by the secondary multiplier such that their flow rate is matched to the primaries (ie if we send a 1ms pulse to the primaries, and it would take the secondaries 4ms to deliver the same amount of fuel, then the multiplier should be 4), it is therefore possible to calculate delivered fuel prior to the injector split calculation, obviating the need for a secondary injector flow scaling in ml/sec in the consumption setup.
Hope this helps,
Pat.
The injector consumption scaling sets the nominal flow rate of one fuel injector, in ml/sec. When a fuel pulse is scheduled a theoretical fuel delivery is calculated based on this flow rate and the injection time; this happens on a per cylinder basis. Things that are not taken into consideration are factors like the battery adder (since no fuel is being delivered in this time) and relative fuel pressure multiplier (because we are still delivering the same amount of fuel as we would have done had the pressure been nominal and the final injection pulse not been modified for a non-nominal fuel pressure). With regard to the secondary injectors, their pulse width is modified by the secondary multiplier such that their flow rate is matched to the primaries (ie if we send a 1ms pulse to the primaries, and it would take the secondaries 4ms to deliver the same amount of fuel, then the multiplier should be 4), it is therefore possible to calculate delivered fuel prior to the injector split calculation, obviating the need for a secondary injector flow scaling in ml/sec in the consumption setup.Hope this helps,
Pat.