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Spray formation and mixing for direct injection under engine conditions

Objective



The main objective of this project is to provide information which will improve understanding of fuel-air mixing in Direct-Injection for Diesel and gasoline engines. In both cases, it is necessary to study the consequences of the flows engendered by ports and valves, high pressure sprays, and their impingement on surfaces. It will be achieved by a combination of measurement and calculation methods which will be developed for this purpose. The emphasis of the experiments will be on improved understanding as required by the Industrial Partners to complement the work of the current BRITE-EURAM Project (BE95-1284).

The main outcomes of the research will be the experimental results which will provide new insight in the different processes, experimental methods developed specifically for the investigation of direct injection in Diesel and gasoline engines and a validated method for the calculation of direct-injection processes in engines, which is based on a computer programme developed for engines under EU Contracts JOUE-CT910083 /JOU2-CT93-0330, with new developments to represent the sprays of direct injection, and combustion.
Experiments will be performed in constant-volume vessels, closed loop injection test rig and in engines, with spray and air-flow characteristics as the main variables. The calculation method will represent the measured data and allow extrapolation conditions outside the range of the measurements.
Prototype gasoline direct injection systems, and high pressure Diesel injection systems, will be used as the basis of the experiments. Additionally, a new concept of direct injection through a high number of small orifices will be investigated in a test rig and in Diesel engines.

The long term final objective of the research is to reduce consumption and pollutants in future engines.

The work content is divided into four tasks.

TASK 1 D.I. DIESEL SPRAYS: Characterisation of sprays provided by flexible electronic Diesel injection systems. Generation of a wide experimental data base to improve understanding of the processes of atomisation, coalescence, spray-air interaction and evaporation. Correlation with engine performance. Development of new high-number small-hole injectors.

TASK2 D.I.GASOLINE SPRAYS: Characterisation of sprays as functions of pressure and temperature.
Correlation of the spray features with engine performance. Development of new measurement techniques.
Generation of a wide data base.

TASK 3 SPRAY MODELLING: Formulation of spray models, incorporation in CFD engine codes, comparison with measurements and use to predict injection schedules for DI engines.

TASK 4 COORDINATION TASK: Exchange of scientific and technical information between tasks. Synthesis of results for Diesel and Gasoline.
The advanced measurements techniques to be used and partly developed, include forms of LDA and PDA with support from high-speed photography and shadow-Doppler velocimetry to identify non-spherical droplets and ligaments, single and double laser methods, forms of PIV and Mie scattering, concentration measurements and thermography. These optical methods will be used in conjunction with techniques for the determination of engine performance in terms of cylinder pressure, speed and load and with purpose-built control systems.

Coordinator

UNIVERSIDAD POLITECNICA DE VALENCIA
Address
14,Campus De Camino De Vera 14
46022 Valencia
Spain

Participants (7)

AVL - List GmbH - Gesellschaft für Verbrennungskraftmaschinen und Messtechnik GMBH
Austria
Address
48,Kleiststraße
8020 Graz
Centro Ricerche Fiat ScpA
Italy
Address
Strada Torino 50
10043 Orbassano Torino
GIE PSA Peugeot Citroën
France
Address
75,Route De Gisy 75
78140 Vélizy-villacoublay
IMPERIAL COLLEGE OF SCIENCE, TECHNOLOGY AND MEDICINE
United Kingdom
Address
Exhibition Road
SW7 2BX London
National Technical University of Athens
Greece
Address
5,Heroon Polytechniou Avenue
15773 Zografou
UNIVERSITE PIERRE ET MARIE CURIE - PARIS VI
France
Address
2,Place De La Gare De Ceinture 2
78210 Saint Cyr L'ecole
UNIVERSITY OF ERLANGEN-NUREMBERG
Germany
Address
Cauerstrasse 4
91058 Erlangen