Woodward GECO, Technical Manual, Page: 52 / 90

GECO

Stoichiometric Manual 03554
44 Woodward
Valve-Learn %
: The learned fuel valve position commands that the control will
use in the event that OPEN LOOP mode is activated for any reason. A position is
learned for each load point represented by the Mdot Fuel values above. New
values are learned only when the engine is operating in a steady state and the
K_Valve_Learn is greater than zero. When utilized, actual fuel valve position
command values are interpolated from the two closest values from the table.
Screen 4: Valve Learn Parameters
Mdot_fuel
: The current
calculated fuel mass flow value
in units of pounds per hour per
liter of engine displacement.
Mdot_air
: The current
calculated air mass flow value in
pounds per hour per liter of
engine displacement.
Mdot_air breakpoint
: The value
of air mass flow above which the closed loop function is enabled. Also, it divides
“high loads” from “low loads” for purposes of blocking the Valve-Learn function.
Mdot_fuel_change
: The current fuel flow derivative or rate of change in units of
percent per second. This is a measure of the magnitude of engine transient
response to a load change.
Mdot_fuel_trig
: The trigger point at which the control temporarily switches to
OPEN LOOP mode and utilizes the Valve-Learn table for better transient
response by the control.
Mdot_fuel 2.20 lbm/hr/l
Mdot_air 20.0 lbm/hr/l
Mdot_air breakpoint 10.0 lbm/hr/l
Mdot_fuel_change 0 %
Mdot_fuel_trig 30 %