The research progress of numerical simulation technique with respect to grain selection

aeroengine turbine blades manufactured by HRS directional solidification method and industrial gas turbine（IGT）blades manufactured by LMC method was introduced

respectively.The mathematical and physical model of these two directional solidification processes was described

and the merits and dis-merits of them were analyzed comparatively.To a great extent

the quality of single crystal blades depends on the geometrical structure of spiral selector.The invalidation of selector design may decrease the selecting efficiency and lead to stray grains.The process for producing single crystal blades was optimized by means of the simulation of temperature field and microstructure.Moreover

the more complex process for producing IGT blades was simulated to reduce R&D cycle and save the cost.