Study of homogeneous combustion and knock in spark ignited engines
This report is the summary of work on homogeneous combustion and knock in spark ignited engines. The work focussed on experimental knowledge of turbulent flame initiation and propagation in real engines up to the point where knocking combustion occurs, taking into account air flow and turbulence effects. This led to setting up a database which could be used to validate 3D codes combustion predictions. An experimental and modelling programme was also conducted to measure the auto-ignition delay in engines and to model the complicated chemical kinetic process either on extended or reduced schemes bases. The numerical algorithms of the SPEED flow simulation code developed in a separate parallel project were extended to allow homogeneous combustion calculations. Flame propagation and flow velocities were measured in a 4-cylinder SI engine with optical access to the combustion chamber via transparent pistons. Another engine was equipped to allow optical access in the combustion chamber of a single cylinder, and set up on a bench, for measurements at given crank angles. Different numerical models were tested for simulating knock in engines and their performances compared with experimental results. All these models were based on the principle that knock is caused by auto-ignition of the air/fuel mixture and were thus built on more or less complex chemical kinetics mechanisms.
Bibliographic Reference: EUR 13919 EN (1992) 29 pp., MF, ECU 4, blow-up copy ECU 6
Record Number: 199210120 / Last updated on: 1994-12-02
Original language: en
Available languages: en