RANS simulations for sensitivity analysis of compressor transition duct

This paper presents a numerical investigation of a strutted annular transition duct used to connect the low pressure and high pressure compressors of aircraft gas turbine engine. Data was generated for one- and six-strut configurations with the United Technologies (UTC) flow solver. For reference, some cases were also run with the ANSYS FLUENT software package. The validity ofthe computed velocity and pressure loading distributions was established with the existing experimental data available in the open literature. Mean streamwise velocity profiles are in good agreement with data along the entire length of the duct with some discrepancies in the boundary layers adjacent to each casing. Axial velocity distributions at all locations show a good match in the width of the wake. However, the wake strength is not always well matched. Axial velocity contours illustrate a well-defined wake at the strut trailing edge with no significant regions of flow separations, similar to the experimental data set. Obtainedaxial static pressure loading distributions along the midline of the duct, about the strut and duct-strut combination indicate good match with measurements. The static pressure loading distributions along the strut at different heights are presented and compare very well with experiment. Additionally, at 10 percent strut height the superposition of strut and duct static pressure distributions shows good agreement between simulation and theoreticaldata up to 70 percent length. The loss distributions across the duct at four axial locations and integrated losses indicate increasing development of loss near the endwalls through the duct. Finally, sensitivity studies examining the influence of duct length and Mach number on pressure loading were also performed for the case of the one-strut duct.