DUCTED FLOW CONTROL IN A TRANSONIC COMPRESSOR, METHODS AND ANALYSIS

Abstract

Compressor development is crucial for enhancing gas turbine engine performance. Variations in inlet flow, whirl, and distortion can lead to compressor stall or surge, resulting in flow detachment within blade passages. This study aims to improve the stall margin in the NPS military fan (NPSMF) transonic compressor by incorporating passive flow control devices on the rotor blade tips, housed in casings. Previous thesis students’ modeling, manufacturing, and computational analysis methods were utilized to expand upon this research. Experimental tests were conducted on three types of casings: a smooth casing, an internal passage casing, and a novel “NACA” casing. Various engineering plastics like polycarbonate and PEEK were used for casings through fused deposition modeling (FDM) printing. Aluminum casings, capable of withstanding higher temperatures, were created using powderbed and liquid metal jet printing (LMJP). Manufacturing fidelity was measured and experimentally tested for each casing, while computational simulations were obtained for all experimental tests. This project serves as an evaluation of each casing’s performance and a review of their creation process, offering valuable insights and recommendations for future manufacturing of passive recirculating casing treatments. The internal passage casing showed minor stall margin improvements of approximately 2%, while further research is needed to establish a comprehensive performance profile for the NACA casing.