中文摘要：

针对不同底吹模式下熔池搅拌效果进行底吹搅拌试验研究,探索底吹氧枪倾角、氧枪排数及氧枪是否对称排布等因素对熔池搅拌效果的影响.采用单一变量分析方法,基于同调群理论和图像分析的贝蒂数多相流混合效果评价方法对不同底吹模式下熔池搅拌混匀时间进行计算和对比.首先,利用图像处理技术对获取的试验图样进行灰度化及二值化处理,其次,获得二值化图样的贝蒂数,最后,利用平均值法得出底吹熔池搅拌宏观混匀时间.对十四组不同工况的研究发现：分析对比不同底吹模式下的混匀时间,得出最佳氧枪倾角为0°,最佳氧枪排数为双排,且氧枪对称排布优于氧枪非对称排布,在底吹熔池搅拌混合试验中工况L（10）的宏观混匀时间最短为16.14 s.可为降低生产成本、增加氧枪寿命、强化熔池生产及优化熔池工艺过程提供了一定的实验依据.

英文摘要：

The mixing effects of molten pools in different bottom blowing modes are explored through bottom blowing stirring experiments.The major considered parameters of the lances include the inclination,the numbers,and the distribution（symmetric or asymmetric）.The single variable analysis method is adopted in this paper.The Betti numbers multiphase flow mixing effect evaluation method,based on homology group theory and image analysis,is employed to calculate and compare the mixing time of different modes.Firstly,image processing techniques are used to obtain experimental images of gray and binarization.Secondly,the Betti numbers of binarization processing images is calculated.Finally,the average method is applied to the calculation of the macro mixing time of bottom blowing stirring molten pool.It is found out through comparison and analysis of research results in fourteen different working conditions that the best angle of lance is 0°,that the optimal rows of lance is double,that the symmetric distribution is better than the asymmetric one,and that the shortest macro mixing time is 16.14 s under the operating condition L（10）.This study can provide some experimental basis for reducing the production cost,increasing the lance life,as well as strengthening and optimizing the production technological process.