Study on the Behavior of Near-Field Dilution of Thermal Buoyant Jet Discharged Horizontally in Compound Open-Channel
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摘要: 采用考虑浮力效应的RNG k-ε双方程模型,结合混合有限分析法对复式断面明渠流中水平圆孔热水浮力射流进行了数值模拟,对其近区稀释特性及二次流结构进行数值分析.同时,采用三维ADV测速仪及温度测量仪对其近区典型断面的:1) 横断面主流速等值线分布;2) 二次流;3) 横断面温度等值线分布进行了试验测量.数值模拟结果与试验资料的对比表明,考虑浮力效应的RNG k-ε模型能够较好模拟射流在环境来流、浮力效应、复式断面二次流等因素作用下,所表现出的分叉现象、附壁效应(Conada效应)和边滩二次流现象.Abstract: The RNG k-epsilon model with consideration of the buoyancy effect,which was solved by using the hybrid finite analytic method,was used to simulate the mixture of the horiz ontal round thermal buoyant jet in compound open channel flow.The mixing features near the spout and flowing characteristic of the secondary currents were studied by numerical simulation.Meanwhile,1) the distribution of the measured isovels for stream-wise velocity,2) secondary currents,3) the distribution of the measured isovels for temperature of typical cross-section near the spout,were obtained by using the three-dimensional Micro ADV and the temperature measuring device.Compared with experimental data,the RNG k-epsilon model based on buoyancy effect can preferably simulate the jet which performs the bifurcation phenomenon,jet reattachment(Conada effect) and beach secondary currents phenomenon with the effect of ambient flow,buoyancy,and secondary currents of compound section and so on.
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Key words:
- turbulence model /
- compound channel /
- buoyant jets /
- hybrid finite analytic method /
- secondary currents
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