Cavitation: CFD Analysis of Cavitation Dynamics in a Converging-Diverging Nozzle

The main goal of this master thesis is to reproduce by CFD computations the characteristic cavitation dynamics in a venturi which were experimentally discovered at TU Delft by Jahangir and al. The different cavitation regimes were obtained by modifying the global static pressure and flow velocity in the flow loop. Based on this, three different...

Dynamic behaviour of the Sognefjord bridge: Analysis and review of the world's largest floating bridge design

A project is under way to replace the ferry crossings in Norway's highway E39 with fixed links, such as highway bridges or tunnels. This thesis research is on the crossing located at the Sognefjord, the widest and deepest of the straight crossings in the E39 highway. Previous thesis projects at IV-Consult have yielded a design for a floating...

Simulations for an expanding gas jet with Joule-Thomson cooling

This study was aimed at improving the accuracy of the model predictions for the minimum fluid and inner wall temperatures for cold, low-pressure start-up of wells that produce oil or gas. Due to the large pressure drop over the well head choke, the so-called Joule-Thomson cooling will give a very low temperature of the<br/>expanding gas jet. Low...

Bridging PIV spatial and temporal resolution using governing equations and development of the coaxial volumetric velocimeter

A series of techniques is proposed for volumetric air flow measurements that are based upon the principles of particle image velocimetry (PIV). The proposed techniques fall in two categories; part 1 of this dissertation considers measurement data processing using constitutive laws and part 2 focuses on development of a coaxial volumetric flow...

Computational fluid dynamics of gassed-stirred fermenters

The current understanding of the transport phenomena involved in the operation of industrial fermenters is not sufficient. This is reflected by the limitations seen in their design and operation. A better insight in the local processes taking place (hydrodynamics, gas dispersion, mixing, microbial kinetics) is required to be able to make a step...

Reduced-order modelling for prediction of aircraft flight dynamics: Based on indicial step response functions investigating agile aircraft undergoing rapid manoeuvres

During aircraft design,multiple tools are utilised to inspect the performance of the configuration. As the design matures, higher fidelity analyses are conducted to predict the flight dynamics of the aircraft. These analyses are conducted by using semi-empirical relations, numerically analysing flow behaviour, conducting wind-tunnel tests and...

Numerical analysis of blood flow patterns in simplified aortic root with prescribed valve kinematics

The aortic valve is a valve made of three thin flexible leaflets which open and close in order to allow the unidirectional passage of blood from the left ventricle to the aorta. Because of this repetitive motion at each cycle, the valve is constantly exposed to large variations of pressure and hemodynamic forces. Deterioration in its peculiar...

A Numerical trimvariation study for ships operating in off-design conditions

Fuel efficiency is an important factor for the shipping industry both regarding new build vessels and existing vessels. A method to reduce the fuel consumption of existing vessels operating in off design conditions is to trim a vessel in the most optimum trim condition. The current approach to determine the most efficient trim condition is to...

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...

Modernizing Thruster Design: A Numerical Investigation of a Ducted Azimuthing Thruster in Oblique Flow

The rudder-propeller, as the azimuthing thruster was originally called, can be rotated 360 degrees and is capable of delivering full propulsive power in any direction. The azimuthing thruster makes use of a mechanical transmission in order to deliver the power from the prime mover to the propeller. The good maneuverability and the absence of a...

The Development of Downhole Separators in Series, Using Design Models Based on Computational Fluid Dynamics Verified By Laboratory Experiments

One of the major problems associated with oil and gas production is the large volume of produced water. Operators around the world are facing significant costs with the treatment and disposal of produced water. Downhole separation, a relatively new technique, has been developed to reduce the costs of produced water and increase oil production....

Effects of Increasing Aerothermodynamic Fidelity on Hypersonic Trajectory Optimisation for Flight Testing Purposes

In a previous study, the optimal re-entry trajectory of Hyperion-2 has been derived. The mission of the vehicle is to measure hypersonic boundary-layer transition, a phenomena in which the laminar boundary layer turns into a turbulent boundary layer. This is an important feature in hypersonic flow to investigate, as it introduces peak heating...