<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Gotoda, Hiroshi</style></author><author><style face="normal" font="default" size="100%">Maeda, Kazuyuki</style></author><author><style face="normal" font="default" size="100%">Ueda, Toshihisa</style></author><author><style face="normal" font="default" size="100%">Robert K. Cheng</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Periodic motion of a Bunsen flame tip with burner rotation</style></title><secondary-title><style face="normal" font="default" size="100%">Combustion And Flame</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">buoyancy</style></keyword><keyword><style  face="normal" font="default" size="100%">burner rotation</style></keyword><keyword><style  face="normal" font="default" size="100%">lewis number</style></keyword><keyword><style  face="normal" font="default" size="100%">microgravity</style></keyword><keyword><style  face="normal" font="default" size="100%">premixed flame</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2003</style></year></dates><volume><style face="normal" font="default" size="100%">134</style></volume><pages><style face="normal" font="default" size="100%">67-79</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Effects of burner rotation on the shapes and dynamics of premixed Bunsen flames have been investigated experimentally in normal gravity and in microgravity. Mixtures of CH4-air and C3H8-air are issued from the burner tube with mean flow velocity U = 0.6 m/s. The burner tube is rotated up to 1400 rpm (swirl number S = 1.58). An oscillating flame with large amplitude is formed between a conical-shape flame and a plateau flame under the condition of Lewis number Le &gt; 1 mixtures (rich CH4-air and lean C3H8-air mixtures). In contrast, for Le &lt;= 1 mixtures (lean CH4-air and rich C3H8-air), asymmetric, eccentric flame or tilted flame is formed under the same swirl number range. Under microgravity condition, the oscillating flames are not formed, indicating that the oscillation is driven by buoyancy-induced instability associated with the unstable interface between the hot products and the ambient air. The flame tip flickering frequency [nu] is insensitive to burner rotation for S &lt; 0.11. For S &gt; 0.11, [nu] decreases linearly with increasing S. As S exceeds 0.11, a minimum value of axial mean velocity along the center line uj,m due to flow divergence is found and it has a linear relationship with [nu]. This result shows that uj,m has direct control of the oscillation frequency. When S approaches unity, the flame oscillation amplitude increases by a factor of 5, compared to the flickering amplitude of a conical-shape flame. This is accompanied by a hysteresis variation in the flame curvature from positive to negative and the thermo-diffusive zone thickness varying from small to large. With S &gt; 1.3, the plateau flame has the same small flickering amplitudes as with S = 0. These results show that the competing centrifugal and buoyancy forces, and the non-unity Lewis number effect, play important roles in amplifying the flame-tip oscillation.</style></abstract><notes><style face="normal" font="default" size="100%">0010-2180doi: DOI: 10.1016/S0010-2180(03)00082-8</style></notes><label><style face="normal" font="default" size="100%">Combust</style></label></record></records></xml>