Why F1 has fuel flow sensors in 2014

We have had a lot of readers asking why F1 has introduced a fuel flow rate monitoring regulation this season as part of the new rules for the hybrid turbo power units.

This is in the light of Daniel Ricciardo's disqualification for excessive flow rate in Sunday's Australian GP.

JA on F1 technical expert Mark Gillan has written this advisory note on the matter:

It was decided pretty early on in the FiA Technical Working Group meetings (which I was a member of) to agree not only on a maximum fuel quantity (i.e. 100kg) but also to a maximum fuel flow rate in order to ensure that a significant emphasis was placed on both improved whole vehicle efficiency and on reduced fuel consumption. These limits, coupled with the move to the downsized 1.6L v6 engine, would ensure that suitable R+D resource was put into the new ERS which, with the addition of the MGU-H, are at the forefront of a potential technology revolution for new highly efficient down-sized road car and commercial vehicle power units.

The technical regulation for the power unit fuel mass flow is clearly stated in articles 5.1.5 and 5.1.5 which set a max fuel mass flow rate of 100kg/h at, and above, 10500rpm with this maximum reducing as the rpm decreases in line with the formula outlined in 5.1.5. These are maximum values and there is no margin for error if one exceeds these values.

The flow rate is monitored by the new ultrasonic sensor, supplied by Gill Sensors, and as discussed previously the accuracy and reliability of this sensor is key, as the ultimate performance of the car depends on it.

From the FIA Tech Regs for 2014: