Research On A Certain Type Of Gasturbine Blade Cooling Mechanism And Improvement Design

It have been witnessed the exponential increase in gas turbines'cycle power in past decades and the companioning rapidly elevated gas temperature at the outlet of the combustor, which makes turbine inlet temperature that turbine blades exposed to far beyond melting points of conventional heat resistant materials currently available. In response to the fact that advances in material development barely keep abreast with the boosting combustion temperature, the integration of multiple cooling technologies has been applicated. Tremendous efforts have been devoted to develop relatively mature cooling technologies among which there are internal impingement cooling, disturbing ribs, film air cooling and their combinations.Numerical simulation of conjugate heat transfer for the 3rd stage vanes from a certain type of gas turbine is conducted and the results offer reference for analysis on the aerodynamic and cooling behavior of the archetype. Because gas temperature at the inlet of the 3rd stage vanes has been in peril of reaching the permitted point of the material, there are eight kinds of retrofit adding ribs to the internal walls on the inner cooling tunnel. Modifications of eight distinct types consist of V-shaped ribs of 60°and 45°, each of which has two derivations featuring by disconnected ribs, straight and disconnected ribs of 90°. Investigations on heat transfer mechanism as well as simulating results of heat transfer performance under three different amounts of cooling media for the archetype and its eight modifications indicate that straight ribs of 90°show highest capability to cool the leading edge. However, by weighing and balancing integral heat transfer efficiency and friction coefficient of leading edge, trailing edge, pressured surface and suction surface, the V-A shaped fin of 45°turns to be the optimized modification.In our modeling work, the Unigraphics NX 6.0 is employed to address pre-process part in light of relevant parameters, and the code ICEM functions to realize domain discretization and generate proper grids. Based on these preliminary works, parallel computation is processed with code CFX because of numerical strategies of improved iterative convergence properties to perform conjugated heat transfer simulation. From the prediction results we capture the near-wall flow successfully and obtain distributions of various physical values in the computational domain. The ultimate proposal is afterwards confirmed from comprehensive comparisons of predicted operation behaviors under different design features, by virtue of contour plots of telling values such as heat transfer coefficient and Nusselt Number and curves concerning about related parameters as well. And this modeling work put further light on heat transfer mechanism of cooling technologies used on modern gas turbines.