BADA fuel flow during acceleration/deceleration?

[rjdverbeek]

Hi Joost,

Am I correct that the BADA fuel model that has been implemented does not take fuel consumption into account for accelerated or decelerated flight?

Wkr,
René

[rjdverbeek]

Hi Joost,

In perfbada.py the thrust and fuel flow is calculated. For the item level thrust (Tlvl) in line 432 it is assumed that the thrust is equal to the drag. Without any accelerations this is true, but in traffic.py at line 421 the acceleration (self.ax) is calculated, but this is never used in the thrust calculation in perfbada.

To my opinion Tlvl needs to have also an acceleration item to take horizontal acceleration/deceleration into account:
Tlvl = lvl * self.D + lvl * self.mass * bs.traf.ax

Wkr,
René

[jooste]

Seems to make sense! I'll check it and look at the implementation.

[ProfHoekstra]

Better use dTAS / dt . This is because traf.ax is the absolute value of an acceleration to be used in kinematic equations in case of a speed change, when lacking other data. The default value is 1 kts/s, and as this is a reference value, this variable also has a non-zero value when the actual current acceleration is zero or negative.

To avoid this confusion in the future, I think we'd better change the variable name to traf.refax or something similar.