单相平面射流实验研究进展

A Review of Experimental Investigationson the Air Planar Jets

本文为水平浓淡煤粉燃烧技术研发基础工作之一。以双矩形气固两相平行射流为研究背景,作者首先考察了主要应用于航空航天的单相平面射流的实验研究。综述表明,描述平面(单一或多平行)射流的主要概念包括:势流核长度、速度半宽、最大速度衰减、湍流场的相似性、湍流特性;影响因素包括:喷口宽度、喷口结构特性,初始条件;测量方法包括:皮托管、热线风速仪、LDV等。调查发现,近场和远场的射流混合特性有本质区别,喷口宽度、喷口间距、动量比对混合影响显著。对于双平行射流,三区结构和湍流特性受初始条件和喷口结构影响明显,主要测试方法的可靠性较高,均能满足工程要求。重要的是,尚没有关于喷口间距较小时双平行射流的研究。

This review is part of the horizontal bias pulverized coal combustion R＆D plan and technological ba- sis of the further study of dual rectangular jets. The paper emphasized investigations of experimental works on the air plane jets mainly for the applications in aerodynamics and aeronautics, and the review showed that by means of concepts of potential flow core length, semi - velocity width, maximum velocity decay, similarity of tur- bulence field, three - zone flow field structure, etc., it was possible to describe the mixing or dispersion of single planar jet or multiple planar jets, factors of influencing jet mixing included slot width, slot structure, ini- tial conditions, and general measuring methods were pitot tube, hot wire and LDV. This review also presented some important findings, e. g. planar jets mixing characteristic in the near field is different essentially from that in the far field, and effects of initial conditions, slot width, slot distance, slot structure and ratio of momentum on three- zone flow field structure and turbulence property are dominant. One of important points is that no any message on dual parallel planar jets of smaller slot distance is available although those studies would be key to pulverized coal combustion. Authors think that the review is one of important references for the horizontal bias pulverized coal combustion tech- nology R＆D of China intellectual right.