Numerical study of boundary layer transition behind a zigzag trip

In this thesis a numerical investigation was performed to increase our understanding of a low Reynolds number transition behind a zigzag trip. This was done with the use of Direct Numerically Simulation (DNS). This means that the Navier-Stokes equations are solved numerically without any use of a turbulence model. The DNS solver of the CFD...

The influence of laminar-turbulent transition on the perfomance of a propeller

The influence of laminar-turbulent transition on a propeller blade’s performance has been investigated in this study, both numerically and experimentally. The computational fluid dynamics (CFD) is performed using the TAU code developed by the German Aerospace Center, as well as an existing propeller lifting-line code. The laminar-turbulent...

Simulations of steady and oscillating flow in diffusers

In this thesis diffuser performance will be simulated with computational fluid dynamics, which will be done with the program Ansys Fluent. The expanding geometry creates an adverse pressure gradient and under certain conditions there will also be separation.<br/><br/>At first a relative simple simulation will be done of a one-directional...

An investigation of numerical analysis for modeling free-surface elevation from flow over a shallowly submerged 2D naca0012 hydrofoil

The bulbous bow is a common feature for large displacement vessels. The purpose of the bulbous bow is to reduce the bow wave, hereby making use of wave cancellation theory. The main drawback of these type of bows is that the drag reduction effect is only present for a limited range of sailing speeds. If the transit velocity is altered, the...