Flow and mixing characteristics of two parallel jets were studied using PIV measurements at different velocities and distances between centers of two nozzles. The results showed that absolute velocity along symmetric line rose but the point of maximum combined velocity barely changed as velocities at nozzle exits were increased. With distance increase between two nozzles, the parallel jets displayed delay in merging process, moving down of combining point, decrease of momentum transported to the symmetric line, and reduce of maximum velocity at combining point. A linear relationship was observed between the spacing ratio and the combining point. Compared to large spacing ratio, small spacing ratio had more obvious impact on the combining point and thus the slope was larger. The turbulence characteristics indicated that main momentum transfer between the two parallel jets occurred in the merging region. As the spacing between two jets was increased, the merging region moved away from nozzle exits.%用激光粒子测试仪(PIV)测量了双矩形喷口平行射流的流场特性,研究了不同喷口速度、不同喷口间距下双射流的混合特性.结果表明,喷口速度增大,双射流对称线上速度绝对值增大,但速度最大值出现的位置基本不变.喷口间距增大后,双射流的混合推迟,合并点后移,传递到对称线上的动量减弱,在合并点上的最大速度值减小.间距比与合并点的关系呈线性;但与大间距比相比,小间距比对合并点的影响更为敏感,关联式斜率更大.对湍流特性分析发现,双射流的主要动量传递发生在混合区,喷口间距增大,混合区与喷口的距离增加.
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