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This paper studies on the subject that calculates melt flow characteristics of multi-strand tundish.For researchers.water model experiment is one of the principal means to calculate the melt flow characteristics of tundish.It gets melt flow characteristics of tundish with residence time distribution curve ( RTD curve) which is measured in water model experiment.Currently,combined model and variance method are widely used to analyze the melt flow characteristics of tundish.However,either combined model or variance method is proposed for the single-strand tundish,they can t be utilized to analyze the melt flow characteristics of tundish directly.Considering the possible nonuniform behaviors of all the strands of a multi-strand tundish for continuous casting of steels,two different averaging and integration methods are used to attain volume fractions of various zones of the whole tundish from the combined model and the variance analysis.One is,on the assumption of uniform sub-tundish volumes and strand flowrates,the strands-averaging method which gets the volume fractions of various zones of every sub-tundish from corresponding RTD curves and then averaging all strands as the result of the whole tundish.The other is the strands-lumping method which averages the tracer concentration of all strands to get the RTD of the whole tundish and then getting the volume fractions of various zones of the tundish.In this paper,it makes a comparison between these methods (including strands-averaging method of combined model,strands-averaging method of variance model,strands-lumping method of combined model and strands-lumping method of variance model).It carries out a water model experiment which is based on the prototype of seven-strand tundish in a factory.And then,it uses these four methods to analyze the data of this typical multi-stand tundish.The results show that the strands-lumping method gives better representation than the strands-averaging method for both combined model and variance analysis.The results show that the plug flow volume from variance model is much bigger than that from combined model while the mixed flow volume from variance model is much smaller than that from combined model.According to the structure of the multi-strand tundish,the mixed flow is confined in the pouring chamber which is much smaller than the rest plug flow region of the tundish.It can consider that the variance model may give better representation than combined model.So.strands-lumping method of variance model should be a reasonable way to analyze the flow characteristics of multi-strand tundish.