To achieve the targets of efficient fuel burn, low pollutant emissions and low noise radiation, new engine design concepts have been developed for next generation aircraft. These designs leverage a more compact engine-airframe integration to reduce drag and distributed turbofans with smaller diameters to control noise. These tightly coupled systems have posed a greater challenge to numerical prediction tools, especially for problems such as aeroacoustics that requires high-fidelity simulations. While high fidelity simulations (e.g., wall modeled/wall resolved large eddy simulations) have demonstrated predictive capabilities for separated boundary layers, transitions, and turbulent wakes, they are often infeasible in design contexts due to their high computational costs, and only limited to component level analysis. This SBIR project will incorporate recent technical advances Cascade has made in low dissipation, compressible flow discretizations and wall modeling for large eddy simulations, as well as an innovative approach for treating stationary-moving interface which is conservative, numerically stable, and computationally efficient. The proposed framework is implemented to exploit cost-effective throughput afforded by modern accelerated architectures (e.g., GPUs). This will finally result in an approach for these turbomachinery flow and aeroacoustic calculations that are both accurate and feasible (with less than 1 day wall clock turnaround times). This affordable approach will eventually provide a high-fidelity computational solution for system level designs.
The GPU-accelerated LES framework will benefit NASA's turbomachinery research by providing an efficient and high-fidelity simulation approach for turbomachinery flows and associated noise problems. Due to much reduced turnaround time, it can also benefit NASA’s next generation aircraft design, such as the design of SUbsonic Single Aft eNgine (SUSAN) aircraft concept, by providing a high-fidelity alternative to the existing RANS based computational tools.
The successful completion of Phase I & II will produce an efficient and affordable solution for high-fidelity numerical predictions of aeroacoustics, turbomachinery and integrated wing-engine configuration at reduced computational cost. These advances are highly aligned with the demand of Cascade’s commercial licensees in the aerospace industry (e.g. Boom, Boeing, Solar Turbines & GE).