Three-dimensional flow structures and scalar mixing of a sand dune-inspired jet in crossflow
Three-dimensional flow structures and scalar mixing of a sand dune-inspired jet in crossflow
复制标题
DOI：
10.1016/j.ijheatmasstransfer.2023.124601
复制
发表时间：
2023
影响因子：
5.2
通讯作者：
Xu Zhang;Wenwu Zhou;Chuangxin He;X. Wen;D. Peng;Yingzheng Liu
中科院分区：
文献类型：
--
作者：
Xu Zhang;Wenwu Zhou;Chuangxin He;X. Wen;D. Peng;Yingzheng Liu
采用粒子图像测速技术（PIV）和延迟分离涡模拟技术（DDES）对沙丘射流横流的流动和混合特性进行了研究。PIV测量在平行于中间平面的平面中进行（Z/D= 0、0.5和1），并研究了三个速度比（VR= 0.4、0.8和1.2）。受沙丘启发的JICF背后的时间平均和湍流特征是强烈的三维：射流倾向于从中平面移动到外平面，并且即使在Z/D= 1时也可以很好地附着在壁上。采用DDES方法模拟了受SD启发的JICF的三维流动结构和混合特性，并以圆柱形JICF为例进行了对比。马蹄涡、弓形剪切层涡和流向滚柱是形成SD构型平均流场中反反转涡对的主要原因。浓度分布分析表明，射流与主流的标量混合与流动特征和旋涡结构密切相关，沙丘射流与主流的混合强度普遍弱于圆柱射流。
This paper performed particle image velocimetry (PIV) measurements and delayed detached-eddy simulations (DDES) to comprehensively investigate the flow and mixing behaviors of a sand dune(SD)-inspired JICF (jet in crossflow). PIV measurements were conducted in planes parallel to the mid-plane (Z/D= 0, 0.5, and 1), and three velocity ratios (VR= 0.4, 0.8, and 1.2) were studied. The time-averaged and turbulent flow features behind the sand dune-inspired JICF is strongly three-dimensional: the jet tends to move from the mid-plane to the outer planes and can stay attached well to the wall even atZ/D= 1. Then DDES method was applied to reveal detailed three-dimensional flow structures and mixing characteristics of the SD-inspired JICF, and a cylindrical JICF was also simulated as a benchmark for comparison. The horseshoe vortex, arch-shaped shear layer vortices, and streamwise rollers are mainly responsible for the formation of the anti-counter rotating vortex pair (anti-CRVP) observed in the mean flow field of SD configuration. Analysis of concentration distributions indicates that scalar mixing between the jet and the mainstream is highly correlated to the flow features and vortex structures, and the mixing strength of the sand dune-inspired JICF is generally weaker than that of the cylindrical JICF.