PhD Proposal: Alex Michael Moushegian

Mon Oct 26 2020 09:00 AM to 11:00 AM
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You are invited to hear a

PhD Proposal


“Dual Solver Computational Modeling
of Tilt-Rotor Shipboard Landing Aeromechanics”

By Alex Michael Moushegian

(Advisor: Prof. Marilyn J. Smith)

Monday October 26  9-11 a.m.

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Shipboard landings are a fundamental capability of naval aircraft operations, and present a unique challenge to pilots due to the complex aerodynamic interactions between the ship airwake and the aircraft aerodynamics. For rotorcraft in particular, the rotor aeromechanics are highly complex and the aircraft spends much more time in the dynamic interface between the two vehicles, further complicating the problem.  As such, detailed analysis and testing must be done to establish the range of safe conditions at which these maneuvers can be performed, as well as to train pilots to perform them.  Typically, flight testing is relied upon as it is the closest analogue to in situ conditions, however, it is quite expensive, time consuming, and some flight conditions may not be producible during the scheduled testing.  With the advancement of computational power in the last two to three decades, computational tools have been investigated as a way to supplement flight testing.  It has been shown that high fidelity unsteady computational fluid dynamics (CFD) simulations are required to capture all of the relevant aerodynamic phenomena in the helicopter-ship dynamic interface, however, these simulations require huge computational domains which limits their applicability to the repeated and extensive testing required to develop reduced-order models.


Hybrid CFD techniques have been developed in recent years with the intent of reducing the cost of rotorcraft CFD simulations through coupling of the CFD solution with various lower-order computational aerodynamic solvers.  Particularly promising for dynamic interface applications is the hybrid CFD/free-vortex wake methodology, which uses CFD to compute the rotor wake in the near-field and a potential flow model in the far-field.  This technique will allow wake-body and wake-wake interactions in the dynamic interface to be modeled without the need for a highly resolved CFD domain in the large region between the ship and the helicopter. This proposal will describe the implementation of this methodology, demonstrate its capability to model general rotorcraft configurations using a coaxial rotor model problem, and validate its ability to capture interactional aerodynamics using a wing-integrated propeller model problem. Finally the validation work needed to demonstrate its applicability to shipboard landing scenarios will be presented, including validation of the framework's ability to capture wake-body interactions using a ground effect model problem and a tilt-rotor fountain effect model problem, and demonstration of the framework in a shipboard landing simulation.


  • Professor Marilyn J. Smith, School of Aerospace Engineering, Georgia Institute of Technology
  • Professor Jonnalagadda V. Prasad, School of Aerospace Engineering, Georgia Institute of Technology
  • Professor Jürgen Rauleder, School of Aerospace Engineering, Georgia Institute of Technology
  • Dr. Susan Polsky, NAVAIR Patuxent River


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