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 of laminar flame was employed to quantify the effects of the equivalence ratio and the pressure of the mixture on turbulent burning velocities. The ratios of the 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. Because the unstertched laminar burning velocities, <I>u<SUB>l</SUB></I> decreased with the mixture pressure, the relative turbulence intensities to the laminar burning velocities, <I>u</I>'/<I>u<SUB>l</SUB></I> increased with the increase in the mixture pressure. The turbulence Reynolds number also affected <I>u<SUB>tn</SUB></I>/<I>u<SUB>l</SUB></I>. <I>u<SUB>tn</SUB></I>/<I>u<SUB>l</SUB></I> increased with the increase in the turbulence Reynolds number due to the decrease in the kinematic viscosity with the pressure. And <I>u<SUB>tn</SUB></I>/<I>u<SUB>l</SUB></I> increased with the decrease in the Markstein number if <I>u</I>'/<I>u<SUB>l</SUB></I>, or the turbulence Reynolds number was constant. Turbulent burning velocities were affected by the turbulence Reynolds number, the relative turbulence intensity and the Markstein number relating to the thermo-diffusive effects and flame instabilities.
|Translated title of the contribution||Study on the Effects of Pressure on Turbulent Burning Velocity of Outwardly Propagating Propane-Air Flame with Turbulence Reynolds and Markstein Numbers|
|Number of pages||8|
|Journal||Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B|
|Publication status||Published - 2006|