Numerical Analysis Versus Experimental Investigation of a Distributor-Type Diesel Fuel-Injection System

A production distributor-type fuel-injection system for diesel engines has been extensively investigated via computer-assisted simulation and experimentation. The investigation was mainly aimed at assessing and validating a sophisticated computational model of the system, developed with specific att...

Full description

Saved in:
Bibliographic Details
Published in:Journal of engineering for gas turbines and power 1994-10, Vol.116 (4), p.814-830
Main Authors: Catania, A. E, Dongiovanni, C, Mittica, A, Badami, M, Lovisolo, F
Format: Article
Language:English
Subjects:
ADVANCED PROPULSION SYSTEMS
AIR POLLUTION ABATEMENT
Applied sciences
COMPUTERIZED SIMULATION
DIESEL ENGINES
Energy
Energy. Thermal use of fuels
ENGINES
Engines and turbines
Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc
Exact sciences and technology
FUEL INJECTION SYSTEMS
FUEL SYSTEMS
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
Numerical analysis
PERFORMANCE TESTING
POLLUTION ABATEMENT
Pumps
Q1
SIMULATION
TESTING 330102 > Internal Combustion Engines-- Diesel
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A production distributor-type fuel-injection system for diesel engines has been extensively investigated via computer-assisted simulation and experimentation. The investigation was mainly aimed at assessing and validating a sophisticated computational model of the system, developed with specific attention given to the pump and to some important aspects concerning the injection pressure simulation, such as the dynamic effects of the injector needle lift, the flow unsteadiness, and compressibility effects on the nozzle-hole discharge coefficient. The pump delivery assembly was provided with a valve of the reflux type. This presented a flat in the collar, forming a return-flow restriction with the seat, and had no retraction piston. A single-spring injector, with a reduced sac volume, was fitted to the system. The numerical analysis of transient flow phenomena linked to the mechanical unit dynamics, including possible cavitation occurrence in the system, was performed using an implicit finite-difference algorithm, previously set up for in-line injection equipment. Particular care was exercised in modeling the distributor pump so as to match the dynamics of the delivery-valve assembly to the pressure wave propagation in the distributor and its outlets. The so-called minor losses were also taken into account and it was ascertained that sudden expansion and contraction losses were significant for the type of pump examined. The experimental investigation was performed on a test bench at practical pump speeds. Pressures were measured in the pumping chamber, at two different pipe locations, and upstream to the needle seat opening passage. This last measurement was taken in order to evaluate the nozzle-hole flow coefficient with the support of the simulation, using experimental values of the needle lift, injection rate, and injected fuel quantity as known variables. The numerical and experimental results were compared and discussed, showing the validity of the model. The injection pressure time history and the influence of the delivery return-flow restriction on the system performance were numerically examined.
ISSN:0742-4795
1528-8919
DOI:10.1115/1.2906890