Keith King教授是澳大利亚阿德莱德大学化工系教授。他所在的流体动力学与燃烧科学小组在煤颗粒燃烧、生物质燃烧碱金属特性，湍流火焰特性及激光火焰诊断方面都颇有建树。在蔡老师和姚老师的邀请下，他每年都会至少来我系一次，进行访问交流。去年还有一名学生通过高水平大学公派项目到阿德莱德大学学习。他此次将于5月14日上午10点来我系访问，并受邀做关于火焰三维OH图像激光诊断的演讲。老人家很和蔼可亲，欢迎大家踊跃参加，积极交流。

                             The hydroxyl (OH) radical is indicative of the hot combustion region within a flame. Large scale, 312 ´ 205 mm2, OH images were recorded in a well-controlled mechanically precessed jet. The jet was controlled so that OH images can be obtained at 8 selected angles between the laser sheet and the nozzle axis. The conditionally recorded OH images are then used to construct a 3-dimensional OH structure.  All the OH images recorded revealed the presence of OH sheets encasing regions of fuel-rich mixture, as to be expected from previous investigations. However, the very base of the precessing jet flames is quit different from that of the simple jet flame, with OH sheets extending right across the centre of the jet.  The constructed three-dimensional OH concentration field reveals clear evidence of a flame structure that processes with the nozzle in this near-field region. However, such phase-averaged structure is only evident in the flame to an axial distance of about 15 nozzle diameters.  Further downstream the flame structure is axi-symmetric, probably dominated by buoyancy. The precessing jet flames also exhibit more broad sheets of OH than those of the simple jet flame. This is different from the usual OH distribution associated with a simple jet, which shows thin OH regions encasing the central fuel rich fuel jet. The existence of the broader hydroxyl distribution may be associated with their high radiant fraction and low NOx emissions