PhD in 2-way Fluid-Structure Interactions with OpenFOAM for tidal turbines

Updated: 9 months ago
Location: Cranfield, ENGLAND
Deadline: The position may have been removed or expired!

Fluid-structure interactions (FSI) require knowledge in both structural mechanics (FEA) and computational fluid dynamics (CFD). Since both methods operate at different time scales, efficient 2-way coupled FSI simulations are computational demanding. Therefore, the goal in this PhD is to develop efficient CFD and structural methods and couple them together in OpenFOAM to develop an efficient 2-way coupled FSI method for tidal turbines.


Pressure-velocity coupling is a crucial aspect of numerical simulations of incompressible flows. However, achieving an accurate and stable coupling between these two quantities presents a significant challenge. One major challenge is the nonlinearity of the governing equations, which can cause oscillations or divergence in the solution. Another challenge is the numerical treatment of the pressure term, which can lead to spurious pressure modes or checkerboard patterns. Additionally, the choice of coupling algorithm can greatly affect the accuracy and efficiency of the solution and iterative methods such as the SIMPLE and PISO algorithms are widely used but may require careful tuning to achieve optimal performance. Work on incompressible methods at Cranfield have generated a range of new, unified incompressible pressure-velocity coupling algorithms that have shown orders of magnitude reductions in computational cost.

Finite Element Analysis (FEA) simulations have become a popular tool for predicting the behavior of complex engineering systems, including those involving fluid-structure interaction. One important aspect of such simulations is the inclusion of the added mass effect, which refers to the inertia of the fluid mass that is displaced by the motion of a solid body. Work at the University of Technology of Compiegne on the added mass effect have shown that the convergence rate can stagnate, or worse, diverge for certain parameter combinations. Research into its effect for high density mediums such as water requires further research.

The aim of this PhD project, then, is to couple the newly developed unified incompressible pressure-velocity coupling algorithms with an FEA solver that accounts for the added mass effect. The goal is to achieve faster convergence on both the FEA and CFD solver side so that 2-way fluid-structure interaction simulations are possible for complex cases such as tidal turbines.

This is a fully-funded studentship, covering tuition fees and a maintenance bursary. A home student (UK) is given preference, but any other nationality will be considered and may be accepted if no suitable home student can be identified. This project is jointly sponsored by Cranfield University and the University of Technology of Compiegne.

At the end of the project, it is expected to have gained a better understanding on how these novel pressure-velocity coupling algorithms paired with an added mass-aware FEA simulation will impact the computational cost, especially for high density environments such as water, where added mass effects become important. The student will be expected to develop a substantial amount of code C++ and implement a new FSI solver into OpenFOAM, covering both the CFD and FEA part.

This PhD project is jointly supervised by Cranfield University and the University of Technology of Compiegne and the successful applicant will spend 18 months at each institute. Additional training is available for students at Cranfield university through the Cranfield doctoral network and travelling to conferences will be covered for high-quality conference papers.

It is expected that the successful applicant will gain a fundamental understanding of OpenFOAM, in particular on how to extend it with C++ code to write bespoke solver applications. Therefore, the selected student will obtain an in-depth knowledge on modelling processes paired with practical knowledge on tidal turbine applications which can be applied to a range of applications in the engineering sector.

Additional references related to the project:

E. Lefrancois, “How an added mass matrix estimation may dramatically improve FSI calculations for moving airfoils”, Applied Mathematical Modelling, Vol. 51, pp. 655-668, 2017.

E. Lefrancois, A. Brandely, S. Mottelet, “Strongly coupling partitioned scheme for enhanced added mass computation in 2D fluid-structure interaction”, Coupled Systems Mecahnics, An International Journal, Vol. 5, No. 3, pp. 235-254, 2016.

L. Könözsy, D. Drikakis, “A Unified Fractional-Step, Artificial Compressibility and Pressure-Projection Formulation for Solving the Incompressible Navier-Stokes Equations”, Communications in Computational Physics, Vol. 16, No. 5, pp. 1135-1180, 2014.


Sponsored by Cranfield University (UK) and the University of Technology of Compiegne (FR), this studentship will cover tuition fees at both partner universities and provide the successful student with a monthly maintenance bursary.

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