Continuous Closed-Loop Transonic Linear Cascade for Aero-Thermal Performance Studies in Micro-Turbomachinery

Abstract

The present work summarizes the design process of a new continuous closed-loop hot transonic linear cascade. The facility features fully modular design which is intended to serve as a test bench for axial micro-turbomachinery components in independently varying Mach and Reynolds numbers ranges of 0 – 1.3 and 2·104 – 6·105 respectively. Moreover, for preserving heat transfer characteristics of the hot gas section, the gas to solid temperature ratio (up to 2) is retained. This operational environment has not been sufficiently addressed in prior art, although it is critical for the future development of ultra-efficient high power or thrust devices. In order to alleviate the dimension specific challenges associated with micro-turbomachinery, the facility is designed in a highly versatile manner, and can easily accommodate different geometric configurations (pitch, ±20° stagger angle, ±20° incidence angle), absent of any alterations to the test section. Owing to the quick swap design, the vane geometry can be easily replaced without manufacturing or re-assembly of other components. Flow periodicity is achieved by the inlet boundary layer suction and independently adjustable tailboard mechanisms. Enabling test-aided design capability for micro gas turbine manufacturers, aero-thermal performance of various advanced geometries can be assessed in engine relevant environments.