Evaluating Turbomachinery Aerodynamic Cross-Coupling Coefficients Using CFD

Project Description

The proposed work is to evaluate the models in use by the industry by performing baseline full-annulus, time-accurate computational fluid dynamic (CFD) simulations of unshrouded centrifugal impellers with varying eccentricities (axis of rotation offset from machine axis) and whirl angular velocity. Currently, aerodynamic cross-coupling coefficients are evaluated uisng various empirical models such as the Alford equation, API-Wachel, and SwRI-Wachel. These methods were developed for axial machines or shrouded compressors. The above comparison will highlight strengths, deficiencies and applicability of these empirical models. Furthermore, the data obtained from these simulations will help in developing models for unshrouded compressor designs. The findings of these investigations will be published for the benefit of the broader community. The knowledge from executing the compressor stability study will be utilized to simulate and understand the stability of a power turbine used in the D-R/Echogen developed EPS100. This will support the development of sCO2 turbomachinery for advanced power generation. Supercritical CO2 as a working fluid in Brayton cycle is being evaluated by the DOE to benefit research and development in the offices of Nuclear Energy, Fossil Energy and Energy Efficiency and Renewable Energy.