With reference to the model described in [11], in consideration
of the further development of the injection system,
a GT-FUEL [26] model of the fuel flow through the injector is
coupled to the GT-POWER gas exchange and combustion
model. GT-FUEL is a tool for analysis of fuel injection and
hydraulic systems based on the solution of compressible
equations including effects of entrained gas within the liquid
and cavitation typically applied to diesel and gasoline fuel
injection systems and both common rail and unit pump
systems. The injector is modeled as a cam-driven valve
connection. This object defines the characteristics of a camdriven
valve including its geometry, lift profile, and flow
characteristics. The phasing angle of the injector relative to
the global crank angle enables each injector to be phased
according to firing order and interval. Phasing of the injection
with the intake stroke is important to reduce back firing. Start
of injection (SOI) is usually placed about intake top dead
center (TDC) to have the hydrogen entering the cylinder and
none left in the port at the end of injection. Fig. 3 presents
results of standalone GT-FUEL simulations with various
injection pressures and temperatures and back pressures showing the influence of pressure boosting and cryogenic
temperatures on the injector flow rate.