Development of a General Purpose Thermal-Hydraulic Software and its Application to Fuel Injection Systems

An advanced simulation code has been developed that models the fluid, mechanical, and thermal aspects of fuel injection and various thermal-hydraulic systems. The flow model is based on the solution of one-dimensional, unsteady, fully compressible, Navier-Stokes and energy equations. The code solves the governing equations using a finite volume formulation. In addition, the code employs a newly developed equation of state that exhibits the observed behavior of measurable fluid properties such as wave propagation speed. Furthermore, the code allows for multi-component, multi-phase treatment and takes into account pipe wall flexibility based on a quasi-dynamic thick-shell model. Multi-body dynamics are solved using an adaptive step-size Runge-Kutta based solver, and the structural thermal solution is based on a fast-executing finite element solver.

The code, GT-Fuel, has been validated using experimental measurements from both high and low-pressure fuel injection systems. The results obtained from the simulation show good agreement with the measurements. Applications of the software for modeling fuel injection and general thermal-hydraulic systems are discussed, as is the use of integrated simulation for modeling concepts such as hydraulically actuated valves.