TY - GEN
T1 - Computational characterization of unsteady rotor hub wakes
AU - Mobley, Forrest
AU - Wall, Tristan
AU - Coder, James G.
N1 - Funding Information:
This research was partially funded by the US Army’s National Rotorcraft Technology Center program, effort sponsored by the US Government under Other Transaction number W15QKN-10-9-0003 between Vertical Lift Consortium, Inc. and the Government, and by the Government under Agreement No. W911W6-17-2-0003. The US Government is authorized to reproduce and distribute reprints for Governmental purposes notwithstanding any copyright notation thereon. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the US Government. Some images in this paper were created using FieldView, licenses for which were provided through the FieldView University Partners Program.
Publisher Copyright:
Copyright © 2021 by the Vertical Flight Society. All rights reserved.
PY - 2021
Y1 - 2021
N2 - Reynolds stresses and turbulent kinetic energy are studied in the wakes for several helicopter rotor hub geometries in forward flight. Computational Fluid Dynamics (CFD) simulations are performed using NASA's OVERFLOW 2.2n Reynolds-averaged Navier Stokes solver. The simulations impose flow conditions based on previous and current experimental and numerical studies. Discrete Fourier Transforms (DFT) are used to examine velocity harmonics for several frequencies and compared against experimental data. Components of the Reynolds stress tensor are computed and examined. Production, transport, and flux of the turbulent kinetic energy are examined through the rotor hub wakes at six streamwise coordinates. Proper orthogonal decomposition is also used to examine a dominant component of the Reynolds stress tensor. It was found that the scissor arms, previously found to have a significant effect on rotor hub force harmonics, also had a significant effect on the magnitudes of Reynolds stresses and turbulent kinetic energy. Integrated values of turbulent kinetic energy flux and transport indicate that a relation between geometry and turbulent kinetic energy levels exists.
AB - Reynolds stresses and turbulent kinetic energy are studied in the wakes for several helicopter rotor hub geometries in forward flight. Computational Fluid Dynamics (CFD) simulations are performed using NASA's OVERFLOW 2.2n Reynolds-averaged Navier Stokes solver. The simulations impose flow conditions based on previous and current experimental and numerical studies. Discrete Fourier Transforms (DFT) are used to examine velocity harmonics for several frequencies and compared against experimental data. Components of the Reynolds stress tensor are computed and examined. Production, transport, and flux of the turbulent kinetic energy are examined through the rotor hub wakes at six streamwise coordinates. Proper orthogonal decomposition is also used to examine a dominant component of the Reynolds stress tensor. It was found that the scissor arms, previously found to have a significant effect on rotor hub force harmonics, also had a significant effect on the magnitudes of Reynolds stresses and turbulent kinetic energy. Integrated values of turbulent kinetic energy flux and transport indicate that a relation between geometry and turbulent kinetic energy levels exists.
UR - http://www.scopus.com/inward/record.url?scp=85108962090&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85108962090&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:85108962090
T3 - 77th Annual Vertical Flight Society Forum and Technology Display, FORUM 2021: The Future of Vertical Flight
BT - 77th Annual Vertical Flight Society Forum and Technology Display, FORUM 2021
PB - Vertical Flight Society
T2 - 77th Annual Vertical Flight Society Forum and Technology Display: The Future of Vertical Flight, FORUM 2021
Y2 - 10 May 2021 through 14 May 2021
ER -