HEAD-ON QUENCHING OF TRANSIENT LAMINAR FLAME: HEAT FLUX AND QUENCHING DISTANCE MEASUREMENTS

ABSTRACT

This work presents results of quenching distance and heat flux measurements during the head-on quenching of transient laminar stoichiometric methane/air flame in the pressure range 0.05–1.7 MPa. The results of direct visualization have been used to measure the quenching distance and to prove the relationship relating the quenching distance and heat flux to the wall over the global combustion reaction rate. It is shown that quenching distance decreases from 0.43 to 0.016 mm with pressure rise from 0.05 to 1.7 MPa. The maximum wall heat flux increases nonlinearly from 0.35 to 2.3 MW/m² with pressure rise from 0.05 to 1.7 MPa. The dimensionless value of the heat flux depends only slightly on the pressure and decreases from 0.3 to 0.2 with rise of pressure in this pressure range. Flame–wall interaction time is about constant and equal to 0.15–0.155 ms in all ranges of pressure variation.

Keywords:

• heat flux density
• quenching distance
• direct visualization

The authors are grateful to RENAULT S.A. for financial support for the present work and sincerely appreciate Prof. T. Kageyama for multilateral help and useful discussions and Mr. B. Ruttun for the help in carrying out the experiments.