Optimization of a Low Heat Load Turbine Inlet Vane


Book Description

Often there is a distinction between the design of turbomachinery airfoils for aerodynamic performance and durability. However, future aero-engine systems require ever increasing levels of turbine inlet temperature causing the durability and reliability of components to be an ever more important design concern. As a result, the need to incorporate heat transfer predictions into traditional aerodynamic design and optimization systems presents itself. Here, an effort to design an airfoil with both acceptable aerodynamics and minimized heat load is reported. First, a Reynolds-Averaged Navier-Stokes (RANS) flow solver was validated over different flow regimes as well as varying boundary conditions against extensive data available in literature. Next, a nominal turbine inlet vane was tested experimentally for unsteady heat load measurements in a linear cascade. The tests were performed in a reflected shock tunnel to validate the flow solver further at the current experimental conditions, and special attention was paid to leading edge and suction side heat-flux characteristics. The nominal airfoil geometry was then redesigned for minimum heat load by means of both design practice and two types of optimization algorithms. Finally, the new airfoil was tested experimentally and unsteady heat load trends were compared to design levels as well as the nominal vane counterpart. Results indicate an appreciable reduction in heat load relative to the original vane. Thus, it is a credible proposition to design turbine airfoils for aero-performance and durability concurrently.













Aero-thermal Performance of a Two Dimensional Highly Loaded Transonic Turbine Nozzle Guide Vane


Book Description

This contribution deals with an experimental aero-thermal investigation around a highly loaded transonic turbine nozzle guide vane mounted in a linear cascade arrangement. The measurements were performed in the von Karman Institute short duration Isentropic Light Piston Compression Tube facility allowing a correct simulation of Mach and Reynolds numbers as well as of the gas to wall temperature ratio compared to the values currently observed in modern aero engines. The experimental program consisted of flow periodicity checks by means of wall static pressure measurements and Schlieren flow visualizations, blade velocity distribution measurements by means of static pressure tappings, blade convective heat transfer measurements by means of platinum thin films, downstream loss coefficient and exit flow angle determinations by using a new fast traversing mechanism, and free-stream turbulence intensity and spectrum measurements. These different measurements were performed for several combinations of the free-stream flow parameters looking at the relative effects on the aerodynamic blade performance and blade convective heat transfer of Mach number, Reynolds number, and free-stream turbulence intensity.




Gas Turbine Heat Transfer and Cooling Technology, Second Edition


Book Description

A comprehensive reference for engineers and researchers, Gas Turbine Heat Transfer and Cooling Technology, Second Edition has been completely revised and updated to reflect advances in the field made during the past ten years. The second edition retains the format that made the first edition so popular and adds new information mainly based on selected published papers in the open literature. See What’s New in the Second Edition: State-of-the-art cooling technologies such as advanced turbine blade film cooling and internal cooling Modern experimental methods for gas turbine heat transfer and cooling research Advanced computational models for gas turbine heat transfer and cooling performance predictions Suggestions for future research in this critical technology The book discusses the need for turbine cooling, gas turbine heat-transfer problems, and cooling methodology and covers turbine rotor and stator heat-transfer issues, including endwall and blade tip regions under engine conditions, as well as under simulated engine conditions. It then examines turbine rotor and stator blade film cooling and discusses the unsteady high free-stream turbulence effect on simulated cascade airfoils. From here, the book explores impingement cooling, rib-turbulent cooling, pin-fin cooling, and compound and new cooling techniques. It also highlights the effect of rotation on rotor coolant passage heat transfer. Coverage of experimental methods includes heat-transfer and mass-transfer techniques, liquid crystal thermography, optical techniques, as well as flow and thermal measurement techniques. The book concludes with discussions of governing equations and turbulence models and their applications for predicting turbine blade heat transfer and film cooling, and turbine blade internal cooling.