同轴旋流低NOx燃烧器空气动力场中一次风转捩长度

The Twisted Length on Air Dynamic Field of Coaxial Swirl Stratified Flow Combustor

运用CCD摄像机对同轴旋转分层流低N0x燃烧器出口空气动力特性进行了可视化研究，对采集的图像进行了一系列处理。提出了一次风边界转捩长度的概念，并对其进行了定义，进而分析了一次风边界转捩长度的影响因素及其变化规律。研究结果表明：一次风转捩长度是一、二次风旋流强度和一、二次风风量比共同作用的结果，其大小范围取决于两者的配置；只有当两者处于合理配置时，燃烧器才能处于较好的燃烧工况。该研究结果为同轴旋转分层流燃烧器分层机理的研究打下了基础。

Air dynamic field in the original co-axial swirl stratified flow low NOx combustor exit was studied by virtual experiment with CCD video. The obtained images are processed systematically. The primary air twisted length was defined. It shows some influence factors and change law on twisted length. The findings indicate that primary air twist length is the concurrent result of swirl intensity and wind rate of primary, secondary air, and it depends on their arrangement. If the arrangement is reasonable, combustor will be in the better combustion condition. Meantime it lays the foundation for the study of stratification mechanism of co-axial swirl stratified flow combustor.