The focus of Chen’s study, which is leveraging the computational power of the Ohio Supercomputer Center, is to develop improved simulation software and validate the flow field of engine components, specifically as applied to high-pressure compressors and low-pressure turbines.

Each turbomachinery component has unique physical characteristics that present difficulties in design and operation, such as stall in a compressor and cooling in a high-pressure turbine. With a simulation tool that is validated and optimized to run efficiently on a large computer cluster, engine designers will have more physical insight to the complex flow field, which will lead to reduced testing, reduced risk, faster time-to-market and lower costs.

While traditional wind-tunnel testing is often the most straightforward approach, it also comes with high costs and severe constraints on placing the measurement probes, according to Chen. Numerical simulation, using CFD, has provided an alternative for studying such flows at a lower cost and with unconstrained probe placement. Yet, the accuracy of a simulation depends on the accuracy of the mathematical model behind the simulation.

With a simulation tool that is validated and optimized to run efficiently on a parallel computer, engine designers will have more physical insight to the complex flow field, which will lead to reduced testing, reduced risk, faster time to market and lower costs.

Chen’s team is investigating three specific areas of current industrial interest: coupled fluid-structure interaction; active flow control; and turbine film cooling. Improved numerical simulation will allow engineers to analyze complex flow fields and aeroelastic phenomena, such as flutter, limit-cycle oscillations, forced response, non-synchronous vibrations and separated-flow vibrations, which arise from fluid-structure interaction.

Application of a newly developed flow control simulation model for vortex-generating jets in low-pressure turbines will help improve engineers’ understanding of how flow control can be used to increase the performance and operability of gas turbine engines. And, finally, simulations can help engineers accurately predict the effectiveness of film cooling on heat transfer in a three-dimensional, unsteady, rotating environment with actual engine geometry.

This study, “Numerical investigations of rotating components in air-breathing propulsion systems,” is funded through the Air Force Office of Scientific Research and N&R Engineering.