Description / Abstract:
This procedure applies to engine or airframe-mounted fuel pumps.
The procedure recommends single-pass operation to minimize changes
in fuel properties affecting NPSP capability. An optional method
using a recirculation system is also included and may be specified
at the discretion of the equipment specification.
This procedure defines the recommended test setup, test
procedure, data acquisition, and data presentation.
Purpose:
This SAE Aerospace Recommended Practice (ARP) defines standard
procedures to conduct tests and evaluations of aircraft and engine
fuel pumps for the purpose of determining NPSP performance
capability.
NPSP = Total pressure - TVP (Eq.1)
NPSP = ( P static + P Dynamic) - TVP (Eq.2)
The procedure recommended herein is intended to produce useful,
reproducible results at steady state conditions.
This test is not intended to establish altitude, climb rate,
starting, or other transient performance of the article being
tested for a specific aircraft installation. This test does address
interstage or discharge heat input from the engine in addition to
heat generated by the pump itself. This is common to modern engine
fuel systems and can significantly influence NPSP capability. This
is especially true at high turn down conditions as described in
3.1.1.
NOTE: At high flow conditions where metalconditions is
negligible where compared to flow capability to remove heat,
interstage or discharge heat may not be required since inlet pump
elements are unaffected. Prior testing with temperature measured
directly at the pump inlet may be required to determine the
influence of this heat addition.