Earlier fluid mechanics lectures (2022)

29-Nov

Introduction to interface resolving techniques for fluid flow and its application to boiling phenomena

Speaker: Yohei Sato (Paul Scherrer Institute)

Abstract of the lecture

The presented talk will give an overview of interface resolving techniques for two-phase flows, in a way that non-CFD (Computational Fluid Dynamics) user could understand. Special focus is put on the geometric and algebraic VOF (Volume of Fluid) methods. Following the introduction, recent progress in boiling flow simulation developed at Paul Scherrer Institute will be presented. Interface resolving techniques require fine computational grid to capture the liquid-vapor interface, and the simulations were limited to several growing bubbles due to the computational cost. However, thanks to the continuous speedup of computer hardware and the development of numerical modellings, it becomes feasible to compute boiling flow in engineering scale somehow as shown in the figures.

08-Nov

Numerical modelling of the flow around a tidal turbine

Speaker: Marta Camps Santasmasas (University of Manchester)

Abstract of the lecture

Tidal stream turbines are a form of renewable energy that have the capacity to generate 11% of UK’s power. The turbines are submerged in a tidal stream and extract energy from the water current in a similar way to wind turbines. As with wind turbines, the wake generated behind a tidal turbine is highly complex and of utmost importance for the design of tidal turbine arrays. We present CFD results from a single tidal turbine submerged in a tidal channel and subjected to the action of waves. This talk will focus on the configuration of the simulations and the effect of waves on the flow around the turbine. The simulations are carried out with the finite differences Navier-Stokes CFD software DOFAS[1], using Smagorinsky large eddy simulation (LES) turbulence model, synthetic eddy method (SEM) to generate inlet turbulence and actuator line model (ALM) to model the rotating blades of the turbine.