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The growing concerns on environmental protection have been constantly demanding cleaner and more energy efficient vehicles without compromising any conveniences provided by the conventional vehicles. The recent significant advances in proton-exchange-membrane (PEM) fuel cell technology have shown the possibility of developing such vehicles powered by fuel cells. Several prototype fuel cell electric vehicles (FCEV) have been already developed by several major automotive manufactures, and all of the favorable features have been demonstrated in the public roads. FCEV is essentially a zero emission vehicle and allows to overcome the range limitation of the current battery electric vehicles. Being motivated by the laboratory and field demonstrations of the fuel cell technologies, variety of fuel cell alliances between fuel cell developers, automotive manufactures, petroleum companies and government agencies have been formed to expedite the realization of commercially viable FCEV.

As a first step towards the development of a fuel cell powered production vehicle, Ford Motor Company has developed the P2000 fuel cell electric vehicle (FCEV). This prototype fuel cell powered vehicle achieves full passenger car performance and is truly a zero emission vehicle with the only by-product being pure water. Road and dynamometer driving tests show excellent performance results, which supports the continued interest in the realization of a production fuel cell vehicle. However, a significant amount of R&D remains to be done before fuel cells can achieve the levels of reliability and cost of internal combustion engines (ICE).

In recent years, rapid and significant advances in fuel cell technology, together with advances in power electronics and control methodology, has enabled the development of high performance fuel cell powered electric vehicles. A key advance is that the low temperature (80°C) proton-exchange-membrane (PEM) fuel cell has become mature and robust enough to be used for automotive applications. Apart from the apparent advantage of lower vehicle emission, the overall fuel cell vehicle static and dynamic performance and power and energy efficiency are critically dependent on the intelligent design of the control systems and control methodologies. These include the control of: fuel cell heat and water management, fuel (hydrogen) and air (oxygen) supply and distribution, electric drive, main and auxiliary power management, and overall powertrain and vehicle systems.

FuelNet is a generic computer code that predicts the flow transient processes in the fuel delivery systems. FuelNet uses the bond graph modeling technique to match the input and output boundary, and the modal approximation to simulate wave dynamics in the fuel lines. It also contains modules for fuel delivery components and engine operating conditions. This work is an application of FuelNet on the injector noise, the fuel rail fuel pressure pulsation, and the injector maldistribution at various operating conditions, such as the temperature, the fuel line material, the engine speed, and the injector pulse width. The effects of pulse dampers are also studied. Models for effective bulk modulus and modal number are developed to address the effect of fuel line materials and dimensions. The predicted liquid fuel pressure is applied to the acoustic model to estimate the injector noise, i.e., the air pressure inside the passenger compartment.

FuelNet is a generic computer code to predict flow transient dynamics in the fuel delivery systems. It employs modal approximation to simulate wave dynamics in fuel lines. This modal approximation provides the accuracy comparable to the quasi-method of characteristics, which is one step more accurate than the standard method of characteristics. The bond graph approach is used to ensure the whole fuel delivery system is properly connected and the input/output causalities are matched at the junctions and interfaces. All the ordinary differential equations are integrated in the time-domain by the Runge-Kutta method to obtain the pressure and the flow rate. FuelNet takes into account the hydraulic effects of the fuel injector, the pressure regulator, the fuel pump, and the pulse damper, as well as the operating conditions such as the engine speed, the injector pulse width, the injector firing strategy and sequence, and the PID controls.