The effects of pressure on outwardly propagating laminar and turbulent flames were studied for propane-air mixtures at the equivalence ratios from 0.8 to 1.3 and the initial pressures from 0.10 to 0.50 MPa. Turbulence intensity, <I>u</I>' was set to 0.80 and 1.59 m/s. The Markstein number was employed to quanify the effects of the equivalence ratio and the pressure of the mixture on laminar and turbulent burning velocities. Turbulent burning velocities, <I>u<SUB>tn</SUB></I> did not become small with the increase in the mixture pressure although the unstertched laminar burning velocities, <I>u<SUB>l</SUB></I> decreased with the mixture pressure. The ratios of turbulent burning velocities to unstretched laminar ones, <I>u<SUB>tn</SUB></I>/<I>u<SUB>l</SUB></I> increased as the mixture pressure increased. They also increased with the increase in the equivalence ratio. We found that <I>u<SUB>tn</SUB></I>/<I>u<SUB>l</SUB></I> increased with the decrease in the Markstein number irrespective of the equivalence ratio, the initial mixture pressure and the turbulence intensity if <I>u</I>'/<I>u<SUB>l</SUB></I> did not vary so much. Turbulent burning velocities were affected not only by turbulence but also by the thermo-diffusive effects and flame instabilities both related to the Markstein number.
|Translated title of the contribution||Effects of Pressure on Laminar and Turbulent Burning Velocity of Outwardly Propagating Propane-Air Flame|
|Number of pages||7|
|Journal||Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B|
|Publication status||Published - 2005|