Research On Calculation Model Of Flow And Heat Transfer Of Lamilloy Cooling Unit

With the rapid development of modern aviation industry and urgent need of national security, countries put forward higher requirements on the performance of the aeroengine. Lamilloy cooling composites of various cooling technology in one, having great significance for improving the turbine inlet temperature and reducing the amount of cool air, so it will be key technology to the development of a new generation aeroengine. Therefore, the study of lamilloy cooling technology is an important subject for eurbine cooling architects.This paper takes the lamilloy cooling structure of an aeroengine turbine blade as the research object, analysising and researching flow and heat transfer of 1:4:2 type lamilloy cooling unit by numerical simulation, to provide a theoretical basis for future turbine blade cooling structure design.Referring to the relevant literature, three-dimensional model was established, structured grid was divided, numerical simulation ws completed, and heat transfer coefficient results under different pin height were compared with the experimental results. The results show that: the numerical simulation method has certain accuracy during the study of lamilloy cooling unit.Parametric programming independently developed by Harbin Institute of Technology can quickly build models and grids, reducing the manual requirements and greatly improving the efficiency of the computing process. On the basis of this program, Reynolds number, pin location, diameter ratio of pin and inlet holes, pin shape were changed. By contrast parameters such as flow resistance coefficient, Nusselt number, wall temperature, etc., flow and heat transfer characteristics of different parameters within the model were analyzed. The results show that: with the Reynolds number increasing, the diameter ratio increasing, shape of the pin changing, comprehensive heat transfer coefficient will be enhanced, and the pin location has little effect on it.On the basis of deep analysis of flow and heat transfer, reference to relevant literature, by calculating Reynolds number, air inlet temperature, ratio of unit edge length and inlet diameter, ratio of inlet height and inlet diameter, ratio of pin height and inlet diameter, ratio of distance between pins and pin diameter, ratio of air film holes height and air film holes diameter, with the method of superposition and fitting, the overall flow resistance coefficient and Nusselt number empirical correlations of the cooling unit which composites impact, convection and film cooling were summed up, furthermore, as cooling structure design guidelines. In this paper, the results of the empirical correlations and numerical simulation were compared, as the work of the verification and improvement. The results show that: the empirical correlation reflects the flow and heat transfer situation in the lamilloy cooling unit, and have a good agreement to the numerical results.