Design, Flow Field and Heat Transfer Characterization of the Conjugate Aero-Thermal Test Facility at NETL

A new aerothermal test facility was constructed with the objective of studying film cooling performance in an environment that accurately simulates conjugate heat transfer characteristics that exist in engine operation. This paper details the design of the facility and the plan for conducting steady-state film cooling experiments to improve the understanding of conjugate heat transfer scaling from laboratory to engine conditions. The test facility consists of two separate flow channels (hot gas/coolant) and each gas path has a flow conditioning section, a convergent nozzle and a test section/channel with viewports.

Numerical simulations were conducted to predict flow field characteristics supporting the design of the flow loop facility. Preliminary experiments were conducted to characterize the flow field using velocity and temperature profile measurements. In addition, infrared (IR) thermography methods were developed to measure surface temperatures on the hot side of the test plate. The IR measurement methods including calibration of the IR camera is explained in detail. It was concluded that appropriate hot gas path flow conditioning could be achieved using a sparger-like tube, a perforated plate, and a honeycomb-mesh screen system upstream of the test section.  Flow field measurements from preliminary experiments showed that the boundary layer profile follows the law of the wall to a reasonable extent.