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PhD Position 3D Unsteady CFD Model for Multi-Rotor Multi-Body Fluid Structure Interaction

Research / Academic
Delft

Wind turbines and propellers operate in aerodynamic conditions dominated by 3D unsteady flows, rotor and body deformation and strong blade-vortex interactions. For this reason, a design and analysis tool with the capacity of modelling the fluid structure interaction under these conditions is of great importance. Such tool would enable a designer to better understand the physics of the problem and improve the design of the turbine. Producing more efficient and long lasting VAWT’s.
Currently, Eulerian solvers (e.g. OpenFOAM) are very efficient in accurately resolving the flow near solid boundaries. On the other hand, Eulerian solvers tend to be diffusive and to dampen high-intensity vortical structures after a short distance away from the boundary. The use of high order methods and fine grids, although alleviating this problem, gives rise to large systems of equations that are expensive to solve. Eulerian solvers also require mesh generation that can be cumbersome and require manual labour.
Lagrangian solvers, for instance vortex particle methods, have shown to eliminate (in practice) the diffusion in the wake. As a drawback, the modelling of solid boundaries is less accurate and much more complex and costly than with Eulerian solvers (due to the isotropy of its computational elements). Lagrangian models are gridless, and allow for linear combination of solutions and thus superposition of elements.
Given the drawbacks and advantages of both the Eulerian and Lagrangian solvers the combination of both methods, giving rise to a Hybrid solver, is advantageous.
The main objective behind this project is to develop a 3D Hybrid solver implemented in OpenFOAM purposed for lift-driven aerodynamics such as in wind energy and aircraft. More specifically, this PhD project focuses on the addition of fluid-structure interaction capability by introducing a combination of domain deformation and partitioned fluid-structure coupling methods. In a region close to solid boundaries the flow, the full Navier-Stokes equations are solved on a deforming (meshed) domain and coupled to a structure dynamics model (possibly with an arbitrary turbulence model or DNS, the limitations being the computational power and the physical properties of the flow); outside of that region, the flow is solved with a Lagrangian (meshless) vortex particle method. In this hybrid approach, the complexity and size of the deforming mesh problem is substantially reduced as it is only required for a small domain close to the body. Also, interaction between different bodies moving in each other’s vicinity is facilitated through the Lagrangian (meshless) vortex particle.
The project builds upon the work developed during the last eight years by PhD students and PostDocs that resulted in a code, able to model 2D unsteady viscous problems, and in collaboration with PhD students currently working on the 3D extension of this hybrid code.

Requirements:

The candidate should have an MSc degree in Aerospace Engineering from a well-established university, or an MSc degree in related engineering disciplines such as applied physics, applied mathematics, or mechanical engineering with a proven experience (courses, projects, work experience) in the field of computational fluid mechanics. A combination of good mathematical/analytical skills and a strong interest in high-fidelity numerical simulations is required. Experience with OpenFOAM is preferred. Proven experience with such simulations and related data processing is advantageous for this position. Since an important part of research work is dissemination and collaboration, fluent communication skills, both written and orally, in English are of utmost importance. Female scientists are particularly encouraged to apply.
Doing a PhD at TU Delft requires English proficiency at a certain level to ensure that the candidate is able to communicate and interact well, participate in English-taught Doctoral Education courses, and write scientific articles and a final thesis. For more details please check the Graduate Schools Admission Requirements.

Salary Benefits:

Doctoral candidates will be offered a 4-year period of employment in principle, but in the form of 2 employment contracts. An initial 1,5 year contract with an official go/no go progress assessment within 15 months. Followed by an additional contract for the remaining 2,5 years assuming everything goes well and performance requirements are met.
Salary and benefits are in accordance with the Collective Labour Agreement for Dutch Universities, increasing from € 2443 per month in the first year to € 3122 in the fourth year. As a PhD candidate you will be enrolled in the TU Delft Graduate School. The TU Delft Graduate School provides an inspiring research environment with an excellent team of supervisors, academic staff and a mentor. The Doctoral Education Programme is aimed at developing your transferable, discipline-related and research skills.
The TU Delft offers a customisable compensation package, discounts on health insurance and sport memberships, and a monthly work costs contribution. Flexible work schedules can be arranged. For international applicants we offer the Coming to Delft Service and Partner Career Advice to assist you with your relocation.

Work Hours:

38 - 40 hours per week

Address:

Mekelweg 2