典型非圆形入口自激抖动射流燃烧器的研究

Investigation on self-excited oscillating-jet burners of noncircular inlet

通过数值模拟与燃烧实验对三种典型的非圆形入口突扩腔体自激抖动射流燃烧器的流动与燃烧特性进行研究,结果表明:自激抖动射流燃烧器相对于普通直流射流燃烧器的火焰具有更高的扩散率和卷吸率;相对于菱形和王字形突扩腔体自激抖动射流,三角形突扩腔体射流混合最快且湍流强度更大,燃烧室内温度分布均匀性也最好,说明在腔体入口面积一定的情况下,燃烧特性(湍动能、火焰长度、温度场等)与腔体入口截面周长之间不存在简单的单调函数关系.

The flow and combustion characteristics of three typical kinds of Self-excited Oscillating-jet Burners of sudden expansion chamber with noncircular inlet were conducted by numerical modeling and combustion experiments, the results show that the flame of Self-excited Oscilating-jet Burners has much higher diffusion rate and larger flue gas entrainment rate than the traditional jet burner. Compared with the Self-excited Oscillating-jet Burners of sudden expansion chamber with diamond inlet and Wang zi in- let, the jet flow from the burner of sudden expansion chamber with triangular inlet has a superior mixing capability and greater turbulence intensity. It also has the best temperature uniformity. The results also show that under the condition of the same area of inlet chamber, there is no simple monotonic function relationship between combustion characteristics （turbulent kinetic energy, flame length, temperature field, etc. ） and the perimeter of cavity cross section.