Turbotech, Verlustminderung. Teil-Vorhaben 1.2.1.5: Simultane Berechnung der Stroemungen im Kuehlluftkanal und im Aussenbereich mit Hilfe unstrukturierter Rechennetze Abschlussbericht

A method frequently used for the cooling of highly loaded high-pressure turbine-blades is the so called film-cooling. In this technique air taken from the compressor is blown via slots or rows of holes from the inside of the blade to build a protective layer along the blade surface. Today, most of the flow solvers used in the design process of film-cooled turbine blades are modelling the coolant ejection by assuming more or less realistic boundary conditions along the exit planes of the coolant channels. In contrast, for a reliable prediction of the behaviour of the coolant jets and therefore for a good prediction of the blade cooling and the formation of losses, it is necessary to extend the calculation domain as far as possible into the coolant channels. Only in this way a realistic simulation of the interactions between coolant and mainstream is possible. As a first step in the direction of a reliable prediction of the aerodynamic of film-cooled turbine blades several calculation procedures have been developed for the generation of unstructured meshes and for the solution of the two-dimensional Euler- and Navier-Stokes equations using these meshes. The unstructured approach was chosen because of its geometrical flexibility, allowing to mesh arbitrarly formed geometries, and for the easy and efficient way a solution dependent mesh-adaption can be performed. Several test cases with and without coolant ejection have demonstrated the ability of the unstructured approach to cope with a wide range of applications. The developed calculation procedures are forming a base for a later extention to three-dimensional flows. (orig.)SIGLEAvailable from TIB Hannover: F95B2445+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman