Simulating the Aerodynamics of the NASA John H. Glenn Icing Research Tunnel

Abstract

The objective of this study is to develop and employ a numerical simulation strategy for predicting the airflow from the spray bars to the test section of the NASA John H. Glenn Icing Research Tunnel (IRT). In particular, predictions of the mean velocity and turbulence distributions were desired throughout this flow domain to later investigate droplet dispersion. Computational airflow results were produced using the WIND code (developed by NPARC) with a second-order accurate finite difference scheme and the shear stress transport k‐Ω urbulence model. The inflow conditions for the flow domain were derived from the IRT measurements just upstream of the spray bars, which reflected the contributions to turbulence from the upstream heat exchanger wake. It was found that inclusion of the spray bar wakes and the air jets (of the spray nozzles) were required to describe the wind-tunnel turbulence distribution. Because it was impractical to simultaneously resolve the overall flow domain (60 ft long), along with the detailed flow around the 10 spray bars and the flow within a hundred air jets (issuing from 1/8-in. nozzle diameters), these features were simulated individually and then algebraically combined together to give an approximate solution. The results of the spray bar wake combined with the heat exchanger flow yielded good prediction of test section mean velocity and turbulence for the jets-off condition. Inclusion of all of the individual air jets also yielded reasonable resulting predictions of mean velocity and turbulence in the test section.