• Title/Summary/Keyword: 과냉각 대형 액적

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Eulerian-based Numerical Modeling for Impingement Prediction of Supercooled Large Droplets (과냉각대형액적 충돌예측을 위한 오일러리안 기반 수치 모델링)

  • Jung, Sung-Ki;Kim, Ji-Hong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.40 no.8
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    • pp.647-654
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    • 2012
  • Supercooled large droplet issues in aircraft icing have been continually reported due to the important safety considerations. In order to simulate the impingement behavior of large droplets, a two-dimensional and compressible Navier-Stokes code was developed to determine the flow field around the test model. Also, the Eulerian-based droplet impingement model including a semi-empirical approach for the droplet-wall interaction process and droplet break-up was developed. In particular, the droplet-wall interactions were considered as numerical boundary conditions for the droplet impingement simulation in the supercooled large droplet conditions. Finally, the present results were compared with the experimental test data and the LEWICE results. The droplet impingement area and maximum collection efficiency values between present results and wind tunnel data were in good agreements. Otherwise, the inclination of collection efficiency of the present result is over-predicted than the wind tunnel data around a lower surface of the NACA 23012 airfoil.

Wall-Droplet Interaction Modeling and Comparative Study on Deformation Models for the Improvement of Icing Analysis Under SLD Conditions (SLD 조건에서 착빙 해석 정확도 개선을 위한 Wall-Droplet Interaction 수치 모델링 및 Deformation 모델 비교 연구)

  • Bae, Jinkyu;Yee, Kwanjung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.48 no.4
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    • pp.255-267
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    • 2020
  • Under SLD conditions, due to the large size of droplets, physical phenomena such as wall-droplet interaction and deformation have a significant effect on the icing process. Accordingly, many studies have been conducted in order to computationally simulate SLD effects. As one of the efforts, post-processing method have been proposed to describe wall-droplet interaction effect, which modified collection efficiency using Wright model. However, since the model doesn't properly consider the wall condition, it still overestimated collection efficiency and impingement limit. To solve this problem, impingement areas were divided into 3 different regions, and the post-processing method was introduced with the new wall-droplet interaction model developed based on Bai and Gosman rebound model. In order to consider the effect of deformation, the most suitable model was selected by comparing the deformation models used in the various icing codes. As a result, the modified post-processing method showed improved accuracy in predicting the impingement limits and collection efficiency by further estimating mass flux loss due to rebound, and it was observed that the result was the closest to the experimental data when the deformation effect was included by using Wiegand model.