The technologies targeted in this project are related to advanced propulsor design that employs low-pressure-ratio fan and its driving component, a lightweight, high-output low-pressure turbine. Advanced aero-engine propulsors employ higher bypass ratio, low-pressure ratio fan designs for improved fuel burn. Lower fan pressure ratios lead to increased propulsive efficiency, and besides enabling thermodynamic cycle changes for improved fuel efficiency, significant noise reduction can be achieved. However, as the fan pressure ratio and fan speed are reduced, the fan design becomes more sensitive to inlet flow distortion and installation stagnation pressure losses.
This project’s effort focuses on the rigorous investigation of the underlying mechanism and the necessary technologies to reduce inlet distortion sensitivity and stability issues in low-pressure ratio aero-engine fan systems. The driving component for the propulsor, the low-pressure (LP) turbine strongly influences the specific fuel consumption of an engine, where a 1 percent increase in LP polytropic efficiency improves the fuel consumption by 0.5 to 1 percent. With efficiency levels already much greater than 90 percent, there will be little scope for improving this aspect of performance without a step change in technology. Increased-lift airfoils lead to reduction of number of airfoil needed for a specific stage loading level, hence the reduction of weight. Increased stage loading designs leads to higher power output or further weight reduction. Being able to understand and predict the unsteady transitional flow in LP turbines is essential in developing airfoils with increased lift and increased stage loading that retain the already high levels of efficiency. This represents an even greater challenge, especially as a reducing core size means that the Reynolds numbers are also reducing. The three-dimensional design of LP turbine airfoils also holds tremendous promise for achieving improved performance.
Researchers will use Department of Energy HPC resources at Argonne National Lab to explore the promising aerodynamic technologies that lead to the successful development of these aero-engine components, as these technologies require large-scale high-fidelity analytical capabilities. GE’s in-house CFD code, TACOMA, will be used for these simulations. The numerical simulation is based on GE’s turbomachinery flow software which solves time-unsteady Reynolds-averaged Navier-Stokes (URANS) equations. The underlying numerical algorithm leverages a parallel-efficient Jameson-Schmidt-Turkel (JST) Runge-Kutta scheme with dual-time stepping for unsteady flows. The software includes well-tested turbulence and transition models, as well as real-gas models and multi-phase flow capabilities.
ALCC Allocation:
4.5 Million Hours
