Rapid Airfoil Design for Uncooled High Pressure Turbine Blades

The aero-engine design process is highly iterative,multidisciplinary in nature and complex.The success of any engine design depends on best exploiting and considering the interactions among the numerous traditional engineering disciplines such as aerodynamics and structures.More emphasis has been placed lately on system integration,cross disciplines leveraging of tools and multi-disciplinary-optimization at the preliminary design phase.This paper investigates the automation of the airfoil generation process,referred to as Rapid Airfoil3D(RAF-3D),for uncooled high pressure turbine blades at the preliminary design phase.This approach uses the TAML(Turbine Aero Mean Line)program in parallel with a database of previously designed P&WC airfoils,in-house design rules and best practices to define a pre-detailed airfoil shape which can be fed back to other analytical groups for pre-detail analyses,such as for structural integrity and vibrations.Resulting airfoil shapes have been aerodynamically validated using an in-house three dimensional Reynolds averaged Navier-Stokes code.RAF-3D will shorten the turnaround time for Pratt&Whitney turbine aerodynamics group to provide a preliminary3D airfoil shape to turbine structures group by up to a factor of ten.Additionally,the preliminary assessments of stress and vibration specialists will be more accurate as their assessments will be based on an airfoil that has had inputs from all functional groups even though it is"first pass"design.

3D modeling of transformation of gaseous pollutants in the high-pressure turbine of an aircraft engine

Aircraft emissions contribute to global climate change and regional air pollution near airports.Understanding the formation and the transformation of emissions in the aircraft engine is essential to properly quantify the environmental impact and air pollution.However,precise investigation of chemical process in the turbine is challenging because of the complexity of the transformation process in the complex flow relating to the moving blade at high temperature and high pressure.We present here,the first published model study of 3D chemical formations inside a high-pressure turbine and first time to compare three numerical solutions(1D,2D and 3D calculations)of transformation of trace species inside an aircraft engine.The model has simulated the evolution of principal precursor pollutant gases(NOx and SOx)and other species(hydrogen,oxygen species and carbon oxides).Our results also indicated strong dissimilarities in chemical transformations of 3D calculations.In comparing the three solutions,the results obtained showed that the difference of mole fractions of species can be under predicted by 75%between 1D and 2D calculations and in the comparison of 2D and 3D calculation,the under predicted difference may be 90%.