Position details

High Performance Computing for CROR and fan
Job offer & Post-Doc › Computational Fluid Dynamics - Aerodynamics

Required Education / Niveau requis

PhD

From / Date de début

asap from June 2011

Duration / Durée

24 months

Context / Contexte

In the current economical and environmental context, efficiency and cost of aeroengines have become a major issue for airframers and engine manufacturers. The objectives in term of pollutant emissions set by the ACARE have prompted motorists and aircraft manufacturers to reduce mass et improve fuel efficiency of aeronautics components.

One way to achieve such improvements is the counter rotating open rotor (CROR) architecture, also referred to as propfan, which consists of two propellers rotating in opposite directions, mounted on the aft part of a turbo engine.
This kind of configuration raises challenges in terms of aerodynamics. Indeed, the two propellers are located very close to each other, hence in strong rotor/rotor interaction, which makes unsteady aerodynamics predictions mandatory.

Another way to achieve such objectives focuses on the design of the intakes of turbojet engines. Besides geometric constraints and the need for high efficiency, a crucial certification issue is the ability to sustain crosswind inflow: norms set a maximum acceptable level of distorsion in front of the fan. Indeed, when the intake is in a crosswind flow, a separation occurs on the side of the intake. Numerical simulations performed at CERFACS showed the capability of CFD to accurately reproduce the physics of the flow around intakes in crosswind in the absence of the fan. However, new design concepts studied by motorists, and SNECMA in particular, require to account for the fan in the simulation, due to its strong upstream influence.

In this context, it becomes necessary that designers consider unsteady flows at the design stage for the prediction of performance.
Unsteady flow simulations at high Reynolds number in complex geometries require huge computational resources.
CERFACS develops advanced numerical methods to reduce the cost of such unsteady flow simulations, especially methods based on a Fourier decomposition of the Navier-Stokes equations and the sliding mesh technique.
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The CERFACS CFD team already implemented these methods in the flow solver elsA (jointly developed by ONERA and CERFACS). This numerical tool is used by major aeronautic companies (Airbus, Safran, Eurocopter).

Description / Description

The objectives of the position are: to perform unsteady flow simulations for a set of complex industrial configurations on high performance computers with a large number of compute cores (~4000 or more) and to adapt numerical methods to get an excellent efficiency.
This position requires a PhD in the field of fluid mechanics with a solid background in CFD. Good skills in parallel code development (MPI, C++, Fortran) are assets. Qualities needed for this position are an interest for applied research and the use of numerical methods to solve industrial problems, independence and a good capability to integrate a team composed of senior researchers and PhD students.

Contacts / Contacts

Name: Boussuge Jean-François
Phone: +33 (0)5 61 19 30 62
Fax: +33 (0)5 61 19 30 00
Email: boussuge@cerfacs.fr