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Numerical and theoretical investigation of helicopter ditching for variations in initial velocity and pitching angle

Published online by Cambridge University Press:  24 January 2025

Y. Lu Open the ORCID record for Y. Lu [Opens in a new window] ,
M. Wang ,
H. Zhi ,
T. Xiao Open the ORCID record for T. Xiao [Opens in a new window]  and
J. Chen
Y. Lu*
Affiliation:
Chinese Aeronautical Establishment, Beijing, People’s Republic of China College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, People’s Republic of China
M. Wang
Affiliation:
Chinese Aeronautical Establishment, Beijing, People’s Republic of China
H. Zhi
Affiliation:
College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, People’s Republic of China
T. Xiao
Affiliation:
College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, People’s Republic of China
J. Chen
Affiliation:
College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, People’s Republic of China
*
Corresponding author: Y. Lu; Email: loux27@nuaa.edu.cn
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Abstract

The dynamic behaviour of helicopter during water impact, considering variations in initial downward velocity and pitching angle, have been investigated numerically and theoretically in the present study. The air-water two-phase flows are simulated by solving unsteady Reynolds-averaged Navier-Stokes equations enclosed by standard $k - \omega $ turbulence model. A treatment for computational domain in combination with a global dynamic mesh technique is applied to deal with the relative motion between the helicopter and water. Results indicate that the initial downward velocity of helicopter exhibits behaviour similar to that of a V-shaped body impacting on water, as does the initial pitching angle. To extend the theoretical approach for predicting the kinematic parameters during helicopter ditching, a shape factor capturing the combined effect of various attributes and an average deadrise angle for asymmetric wedges are also introduced.

Keywords

helicopter ditchingmomentum theorydeadrise angleasymmetric wedge
Type
Research Article
Information
The Aeronautical Journal , First View , pp. 1 - 18
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Copyright
© The Author(s), 2025. Published by Cambridge University Press on behalf of Royal Aeronautical Society

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