Use of 3D Printing technology for developing novel procedure to manufacture runner of Francis Turbine

Turbine having complex profiles has always been a challenge to the manufacturers. With possible errors while manufacturing and surface finishing, it is nearly impossible attaining the same profile of blades or buckets as suggested by the hydraulic design. Specifically in the case of Nepal the manufacturing of Francis turbine runners has been a challenge due to its complex profile and lack of state-of-the-art manufacturing facilities in the Nepalese metal manufacturing industries. Many attempts have been made in the past to manufacture these runners with the available resources. However, the developed turbines have been of smaller size and dimensions and the process used for fabrication have been limited to these small runners. So, for fabrication of the Francis turbine runners a new process has been developed. The process makes use of a rapid prototyping technique called additive manufacturing. The developed method has made the manufacturers easier to manufacture the runners of complex profiles and larger size. The steps from modifications of the cad model to 3D printing and workshop fabrication has been discussed in this paper.