Numerical Simulation of Directionally Solidified Industrial Gas Turbine Hollow Blades by Liquid Metal Cooling

Abstract:

As a new method, liquid-metal cooling (LMC) process is used in manufacturing industrial gas turbines (IGT) blades. Numerical simulation is an effective way to investigate the grain’s growth and morphology, and optimize the process. In this paper, mathematical models for heat dynamic radiation and convection boundary of LMC process is established to simulate the temperature fields. Cellular Automaton (CA) method and KGT growth model are used to describe the nucleation and growth. Simulation results and experimental results are compared. The mushy zone and microstructure evolution are studied in detail. This study indicates that simulation and experimental results agree very well with each other. The withdrawal rate has an important influence on the shape of mushy zone and growth rate of the grain directly. A concave mushy zone is formed and the grain tends to convergent under an excessive high of withdrawal rate. But, the mushy zone has a convex shape and the grain is divergent under a smaller withdrawal rate. A variation withdrawal rate (from 2mm/min to 9mm/min) is found to obtain smooth mushy zone, which improves the parallelism of grain and produces high quality IGT blades.

• Periodical: Materials Science Forum (Volume 850)
• Pages: 386-393
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.850.386
• Online since: March 2016
• Authors: Xue Wei Yan, Ning Tang, Xiao Fu Liu, Xin Li Guo, Guo Yan Shui, Qing Yan Xu, Bai Cheng Liu
• Keywords: Directional Solidification, Industry Gas Turbine Blades, Liquid Metal Cooling, Numerical Simulation

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