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	基于ProCAST二次开发的叶片LMC凝固特征模拟
	唐宁 ; 闫学伟 ; 许庆彦 ; 柳百成 ; TANG Ning ; YAN Xue-wei ; XU Qing-yan ; LIU Bai-cheng
	2016-03-30 ; 2016-03-30
关键词	空心叶片 LMC Procast 二次开发 数值模拟 hollow blade LMC ProCAST secondary development numerical simulation TG244.3
其他题名	Numerical Simulation of Solidification Characteristics of Blades by LMC Based on Secondary Development of ProCAST
中文摘要	燃气涡轮单晶叶片往往具有空心的复杂曲面结构和缘板、叶冠等横截面的突变,非常容易形成杂晶等缺陷。液态金属冷却(LMC)作为一种新型的定向凝固工艺有望解决这一问题,但是尚需用数值模拟进行辅助优化。文中建立了LMC数理模型,通过对ProCAST二次开发建立了浸入过程动态复合边界条件,实现了叶片LMC工艺下的温度场和枝晶参数的数值模拟,考察了工艺对温度梯度、糊状区形态、缺陷指数等凝固特征的影响。LMC能够得到比传统工艺更高的温度梯度和更小的糊状区宽度,在叶片厚大部位能够缩短局域凝固时间,得到更细的枝晶。同时,由于LMC的糊状区形态有利于单晶组织在缘板的推进,抑制了杂晶形核,因而提高了许用拉速,有利于提高生产效率和进一步细化组织、避免雀斑偏析和等轴晶转变(CET)趋势。; SX blades of gas turbines, with inside cavity, curved surface and sharply varying section at the platform and the tip shroud, are usually complicated. Therefore, stray grains occur very easily. A new process of directional solidification, liquid metal cooling(LMC), is expected to solve this problem. Nevertheless, the aid of numerical simulation is necessary to optimize this process. In this paper, the mathematical model of LMC is established and the dynamically combined boundary condition during immerging is modeled via secondary development of ProCAST. Numerical simulation of temperature field and dendrite parameter by LMC process is done to investigate the influence of different processes on the solidification characteristics, such as temperature gradient, shape of mushy zone and defect indicators. Compared with conventional process, larger temperature gradient as well as narrower mushy zone is obtained by LMC. It also leads to shorter local solidification time in the thick part of blade, and thus the dendrite is finer. In addition, the single crystal growth into the platform is much easier with the mushy zone topology by LMC, which tends to stop the nucleation of stray grain. Therefore, higher withdrawal rate can be used to refine the dendrite, to prevent freckle or columnar-equiaxed transformation(CET), and to increase productivity.
语种	中文 ; 中文
内容类型	期刊论文
源URL	[http://ir.lib.tsinghua.edu.cn/ir/item.do?handle=123456789/141667]
专题	清华大学
推荐引用方式 GB/T 7714	唐宁,闫学伟,许庆彦,等. 基于ProCAST二次开发的叶片LMC凝固特征模拟[J],2016, 2016.
APA	唐宁.,闫学伟.,许庆彦.,柳百成.,TANG Ning.,...&LIU Bai-cheng.(2016).基于ProCAST二次开发的叶片LMC凝固特征模拟..
MLA	唐宁,et al."基于ProCAST二次开发的叶片LMC凝固特征模拟".(2016).

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