Temperature variations due to compressibility effects of the liquid fuel were evaluated, for the first time in high-pressure injection system simulation, by employing the energy conservation equation, in addition to the mass-continuity and momentum-balance equations, as well as the constitutive state equation of the liquid. To that end, the physical properties (bulk elasticity modulus, thermal expansivity, kinematic viscosity) of the fluid were used as analytic functions of pressure and temperature obtained by interpolating carefully determined experimental data. Consistent with negligible thermal effects of heat transfer and viscous power losses involved in the flow process, the equation of energy was reduced to a state relation among the fluid thermodynamic properties, leading to a barotropic flow model. A comparison between isentropic and isothermal evolutions in the pure liquid regions was carried out for evaluating the influence of the temperature variation simulation on the macroscopic results given by local pressure time-histories. Furthermore, for cavitation analysis, different thermodynamic transformations of the vapor-liquid mixture were considered and compared.
Catania, A., Ferrari, A., Manno, M., Spessa, E. (2004). Thermal Effect Simulation in High-Pressure Injection System Transient Flows. In Diesel Fuel Injection and Sprays 2004 [10.4271/2004-01-0532].
Thermal Effect Simulation in High-Pressure Injection System Transient Flows
MANNO, MICHELE;
2004-03-01
Abstract
Temperature variations due to compressibility effects of the liquid fuel were evaluated, for the first time in high-pressure injection system simulation, by employing the energy conservation equation, in addition to the mass-continuity and momentum-balance equations, as well as the constitutive state equation of the liquid. To that end, the physical properties (bulk elasticity modulus, thermal expansivity, kinematic viscosity) of the fluid were used as analytic functions of pressure and temperature obtained by interpolating carefully determined experimental data. Consistent with negligible thermal effects of heat transfer and viscous power losses involved in the flow process, the equation of energy was reduced to a state relation among the fluid thermodynamic properties, leading to a barotropic flow model. A comparison between isentropic and isothermal evolutions in the pure liquid regions was carried out for evaluating the influence of the temperature variation simulation on the macroscopic results given by local pressure time-histories. Furthermore, for cavitation analysis, different thermodynamic transformations of the vapor-liquid mixture were considered and compared.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
