CFD for Ship Helicopter Landing Simulations

The use of Computational Fluid Dynamics (CFD) simulations for rotorcraft has so far been restricted to cases of steady flight, due to CPU cost. However, the ever-increasing capabilities of modern CFD algorithms and computers now allow for CFD of manoeuvring vehicles.

The goal of this project is to simulate manoeuvring rotorcraft by coupling a Helicopter Flight Mechanics (HFM) method with the Parallel Multi-Block CFD solver HMB2 developed in Liverpool. This allows for studies of interactional effects between the helicopter and its environment. The case of a ship/helicopter landing is a typical case of strong aerodynamic interaction between the ship and rotorcraft wakes that leads to significant increase in pilot workload and is used to demonstrate the HFM/HMB coupling.

Numerical Method

Flight Mechanics simulation tools implemented in flight simulators are namely multi-body dynamics solvers tailored for rotorcraft that solve systems of differential equations based on the Euler equations of motion. To allow real-time simulation, they implement simplified methods (Blade Element Theory, inflow model, tabulated aerodynamic data) and are therfore dependant on the accuracy of the models.

One such model has been implemented in the UoL CFD solver with the possibility of substituting the simplified models by CFD data. This has the potential for more accurate simulation of rotorcraft in manoeuvring flight but also permits to use CFD to derive the trim state of the aircraft.

Completed Work

  • Implementation of the Helicopter Flight Mechanics model. New implementation of versatile multi-body grid motion in HMB.
  • Validation of HMB for the simulation of ship airwakes and rotorcraft at low advance ratio.
  • Demonstration of HMB2 for simultaneous simulation of ship and rotor wakes.

Future Work

  • Demonstration of the coupled HFM/HMB2 code for CFD-based helicopter-trimming and simulation of manoeuvring flight.

Publications

Journal Papers

  • C. Crozon, R. Steijl and G. Barakos, Numerical Study of Rotors in Ship Airwake, AIAA Journal of Aircraft, to appear, 2014.

Papers in Conference Proceedings

  • S. Lawson, C. Crozon, F. Dehaeze, R. Steijl, G. Barakos, Computational Fluid Dynamics Analysis of Ship Air Wakes Using Detached-Eddy Simulation. Proceedings of the 38th European Rotorcraft Forum, ERF-2012, Amsterdam, The Netherlands, 2012.
  • C. Crozon, R. Steijl, G. Barakos, Numerical Study of Rotors in Ship Airwake. Proceedings of the 39th European Rotorcraft Forum, ERF-2013, Moscow, Russian Federation, 2013.
  • G. Barakos, C. Crozon, R. Steijl and M. Woodgate, Numerical Simulation of Shipborne Rotors, Keynote Lecture, proceedings of the 2nd Asian Australian Rotorcraft Forum, Tianjin, China, 8 Sept. 2013, ISSN 1552-2938.

 

Contact

G. Barakos - Professor, gbarakos@liverpool.ac.uk

R. Steijl - Lecturer, rsteijl@liverpool.ac.uk

C. Crozon - PhD student, crozon@liverpool.ac.uk

CFD Laboratory, School of Engineering, University of Liverpool

Walker Building, The Quadrangle

Liverpool L69 3GH, United Kingdom