Exploring Nonpremixed Jet Flames at High-Pressure and High-Reynolds Number
09:45 - 10:45
Level 0 lecture hall between Al-Jazri and Al-Kindi (buildings 4 and 5)
In an effort to bridge the gap between fundamental combustion research and industrial applications, experiments in flames at high-pressure and high-Reynolds number are needed. A number of new test-rigs designed for such flames have been brought online in recent years but these are typically designed for compact premixed- or partially-premixed flames. Therefore, data on turbulent non-premixed flames at high-pressure remain scarce and the High-Pressure Combustion Duct (HPCD) has recently been commissioned at KAUST-CCRC to overcome this issue. The HPCD accommodates very tall non-premixed flames over large ranges of pressure and Reynolds number and is fitted with windows for advanced optical-diagnostics. In this presentation, the findings of two recent measurement campaigns in the HPCD are presented. The structure of non-premixed syngas jet flames is analyzed using direct imaging and OH-PLIF up to 12 bar and Re = 66,800. It is shown that resorting to higher pressures allows pushing these flames to larger Reynolds numbers, otherwise limited to Re < 20,000 due to localized extinction and blow-off. These measurements also show that syngas jet flames are an ideal candidate to extend the TNF database to higher pressures and challenge advanced LES models under more relevant conditions. Effects of pressure on lifted flames of methane are also analyzed up to 7 bar. In this case, flame chemiluminescence imaging and combined OH-PLIF-PIV measurements show that increasing pressure influences flame stabilization mechanisms. At high pressure, premixed lifted flames are stabilized, which was not observed previously for this fuel at atmospheric pressure.