Abstract: Cooling pipes are crucial components distributed throughout the fusion reactor,whose impact on nuclear safety of the fusion reactor is significant.Therefore,the visualization of cooling pipes is of great importance for improving the safety of fusion nuclear processes.Because cooling pipes are distributed linearly,visualization based on an accurate pipe centerline is a commonly used method.However,extracting the centerline from complex cooling pipe surface models is highly tedious.To address this issue,a solution is proposed by this paper.First,the mean curvature flow algorithm is used to extract discrete points near the center-line.Then,a set of optimization methods are designed,based on the prior knowledge that the pipe segments are cylinders or rings and the connection relationship between the pipe segments,to construct accurate centerline segments from the discrete points,including the type,equation,and connection relationship of the centerline segments.The paper validates the effectiveness of the proposed method by using the cooling pipes of the International Thermonuclear Experimental Reactor(ITER),and the experimental results show that the centerline extracted from the pipes meets the requirements and can effectively support subsequent visualization tasks,proving that the proposed method is effective.

Key words: Fusion reactor, Cooling pipe, Visualization, Center-line extraction, Optimization adjustment