Fuel-Supply Pressure Regulation in a Helicopter Fuel System Using a Constant-Pressure Reducing Valve

Engine-inlet fuel pressure in helicopters can fluctuate during flight manoeuvres because load-factor variation changes both fuel distribution in the tanks and the pressure balance along the fuel-supply pipeline. This simulation-only study investigates a passive pressure-regulation scheme based on a constant-pressure reducing valve (CPRV) for a representative five-tank helicopter fuel system. Mathematical models of the fuel tank, booster pump, jet pump, check valve, fuel-supply pipeline, and CPRV are integrated in AMESim and checked against reported tank-depletion data, fuel-centre-of-gravity data, and code-to-code benchmark results. A controlled same-model isolation check additionally compares a mobile CPRV spool with the same spool constrained at its fully open end stop while all pump, tank, line, demand, load, fluid, reference-pressure, and solver settings remain unchanged. In a longitudinal load-factor ramp to 1 g, the mobile-spool model maintains 1.8042–1.8047 barA, whereas the locked-open control gives 2.4287–2.5917 barA. Across the principal regulated simulations, the maximum absolute deviation from the 1.8 barA target is approximately 0.005 bar. These values are numerical results for the stated model and must not be interpreted as sensor-resolvable hardware accuracy or qualification evidence.