TY - GEN
T1 - Super-cooled large droplet ice accretion reproduction and scaling law validation
AU - Rocco, Edward T.
AU - Han, Yiqiang
AU - Palacios, Jose
AU - Kreeger, Richard
N1 - Funding Information:
This project was funded by NASA Research Grant and Cooperative Agreement Number NNX12AK16A. The authors would like to acknowledge our valuable interaction with NASA Glenn Research Center engineers. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily indicate the views of the U.S. Federal Government or NASA. The authors thank the Penn State College of Engineering for the generous financial and academic support provided by the College of Engineering Graduate Excellence Fellowship.
Publisher Copyright:
© 2016, National Research Council Canada.
PY - 2016
Y1 - 2016
N2 - The simulation of icing conditions is sought for potential aircraft certification, and therefore test facilities that can generate conditions able to reproduce the ice accretion phenomena are necessary. The icing conditions that aircraft endure are outlined in FAA regulations – namely, FAR 14 Part 25 Appendix C and Part 33 Appendix O. Multiple icing facilities exist for FAR 14 Part 25 Appendix C conditions, however developing facilities that can replicate Super-cooled large droplet (SLD) related to Appendix O is difficult due to the shortcomings of horizontal wind tunnels when generating SLD particles. This research attempts to reproduce SLD icing conditions in the Adverse Environment Rotor Test Stand (AERTS) at Penn State University. The facility is formed by icing nozzles located above a rotor. The vertical spray configuration avoids gravitational effects that can bias large droplets towards the lower portion of a test section in a conventional icing wind tunnel. Data from three (3) test conditions conducted suggests that the AERTS facility can adequately produce SLD conditions. Research is on-going to further validate the AERTS cloud reproduction capability. Ice shape modeling software such as LEWICE currently exhibit uncertainty in the SLD regime. LEWICE, with and without an improved heat transfer model developed in prior research were compared to the three (3) test cases. Results suggest that the AERTS facility produces representative SLD shapes, and that the prediction models are valuable in the SLD regime, especially when using improved heat transfer models. The improved prediction consistently better predicted stagnation thickness (26.02±5.03% improvement) and horn formation when compared to legacy LEWICE heat transfer models. The ice shape scaling laws for SLD conditions were also investigated. Standard scaling laws applicable to Appendix C icing conditions were implemented to SLD regimes. These laws have been tested at NASA Glenn Icing Research Tunnel for SLD, but investigation of the scaling laws in other test facilities was requested to further validate the results. The results of this research, comparing three (3) scaling tests with the three (3) SLD tests previously mentioned, suggest that the ice scaling laws apply in the SLD regime as previously discussed in the literature.
AB - The simulation of icing conditions is sought for potential aircraft certification, and therefore test facilities that can generate conditions able to reproduce the ice accretion phenomena are necessary. The icing conditions that aircraft endure are outlined in FAA regulations – namely, FAR 14 Part 25 Appendix C and Part 33 Appendix O. Multiple icing facilities exist for FAR 14 Part 25 Appendix C conditions, however developing facilities that can replicate Super-cooled large droplet (SLD) related to Appendix O is difficult due to the shortcomings of horizontal wind tunnels when generating SLD particles. This research attempts to reproduce SLD icing conditions in the Adverse Environment Rotor Test Stand (AERTS) at Penn State University. The facility is formed by icing nozzles located above a rotor. The vertical spray configuration avoids gravitational effects that can bias large droplets towards the lower portion of a test section in a conventional icing wind tunnel. Data from three (3) test conditions conducted suggests that the AERTS facility can adequately produce SLD conditions. Research is on-going to further validate the AERTS cloud reproduction capability. Ice shape modeling software such as LEWICE currently exhibit uncertainty in the SLD regime. LEWICE, with and without an improved heat transfer model developed in prior research were compared to the three (3) test cases. Results suggest that the AERTS facility produces representative SLD shapes, and that the prediction models are valuable in the SLD regime, especially when using improved heat transfer models. The improved prediction consistently better predicted stagnation thickness (26.02±5.03% improvement) and horn formation when compared to legacy LEWICE heat transfer models. The ice shape scaling laws for SLD conditions were also investigated. Standard scaling laws applicable to Appendix C icing conditions were implemented to SLD regimes. These laws have been tested at NASA Glenn Icing Research Tunnel for SLD, but investigation of the scaling laws in other test facilities was requested to further validate the results. The results of this research, comparing three (3) scaling tests with the three (3) SLD tests previously mentioned, suggest that the ice scaling laws apply in the SLD regime as previously discussed in the literature.
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U2 - 10.2514/6.2016-3279
DO - 10.2514/6.2016-3279
M3 - Conference contribution
AN - SCOPUS:85088059347
SN - 9781624104336
T3 - 8th AIAA Atmospheric and Space Environments Conference
BT - 8th AIAA Atmospheric and Space Environments Conference
PB - American Institute of Aeronautics and Astronautics Inc, AIAA
T2 - 8th AIAA Atmospheric and Space Environments Conference, 2016
Y2 - 13 June 2016 through 17 June 2016
ER -