Influence of Inertia on Inverse Fluidization in a narrow rectangular channel: An Experimental Study

The presence of particles in a flow can change the flow behaviour in an unpredictable manner, that leads us to multiphase flow. Multiphase flows are present in nature and in everyday life around us. The most common example of a multiphase flow, that one can think of, is the treatment of drinking water using liquid-solid fluidization in softening...

Mixed convective heat transfer across a turbulent flow over a porous wall layer - A numerical study

Thermal convection is a phenomenon seen in almost all facets of life, ranging from planetary convection to ocean currents and convection inside the Earth. The physics of thermal convection complicates when a porous wall layer is present. Flow over urban canopies, forest canopies or flow in underground aquifers are classic examples where thermal...

Development of a Large-Eddy Simulation model for flows over urban areas with application to the TU Delft campus

Urban microclimate significantly affects people’s experiences and activities in urban environments by a series of phenomena, among which urban flow is an important factor to be considered. Computational Fluid Dynamics (CFD) method has become a popular tool for studying urban airflow because of its low cost compared with experiment methods....

A DNS study of the rheology of dense suspensions in plane Couette flow

Dense suspensions can be found in various industrial and natural processes. A relatively new technique uses the principle of additive manufacturing to produce products from a wide variety of materials by printing with dense suspensions. To reach a high print quality the suspension rheology must be understood very well. Current knowledge about...

Minimization of drainage time of filled PET bottle with initial rotation: A numerical study

The drainage time of liquid-filled PET bottles can be greatly reduced by pre-rotating the bottle with a certain angular velocity. Depending on the magnitude of the angular velocity, up to four different flow regimes can be distinguished during the emptying of a bottle: bubble regime, transition regime, vortex<br/>regime and the swirl regime. At...

Control of capillary break-up in spiralling liquid jets

A cylindrical column of fluid breaks into drops under the action of surface tension when other forces are relatively small. This phenomenon is called the capillary break-up. Since the introduction of the seminal theory of inertial-capillary jet instability by Rayleigh in the late 19th century, this phenomenon has seen a rich influx of academic...

Path Instabilities of a Rising or Falling Sphere in a Fluid at Rest: An Experimental Study

Multi-phase flows are ubiquitous in nature and in everyday life surrounding us, impacting us in almost all possible ways. The presence of particles in a flow can change the flow behaviour in an unpredictable manner. The simplest example of a particle-laden flow, that one can think of, is the settling of a single sphere under gravity in a...

Numerical Simulation Of Bubble Screens For Mitigating Salt Intrusion Through Sea Locks

Salt intrusion through sea locks causes the mixing of fresh and salt water due to a gravity current. This process may occur gradually over tens of kilometers and affects the required quality of the inland water. A bubble screen alongside the locks is one of the available mitigating measures for this undesired phenomenon. However, current...

Numerical study of the sedimentation of particle suspensions in ducts

Sedimentation of particle suspensions is a relevant process to a variety of applications, such as the reclamation of land and chemical engineering systems. Direct numerical simulations of the settling of a single, two and multiple solid spheres under gravity in a square duct have been performed. The simulations involve 4 different Galileo...

Particle Degradation during Vertical Transportation: Contribution of Abrasive Wear on Polymetallic Nodule Degradation

Manganese nodules have been lying on the deep sea soil for centuries before they became known. The first ones to discover the nodules were Murray and Renard, during their scientific cruise between 1872 and 1876 (Murray and Renard, 1876). The Clarion-Clipperton Zone, located between Mexico and Hawaii, appears to have a virtually inexhaustible...

Instability of the flow over a porous surface: Linear stability analysis

Direct numerical simulations of the fully developed turbulent flow through a porous channel show the appearance of short span-wise rollers at the fluid-porous interface along with the streaky structures of wall-bounded turbulence near the upper wall of the channel. The scope of the present research project is to investigate the instabilities in...

The influence of free-surface turbulence on scum-layer formation

Frictional behaviour of pigs in motion

Pigs (pipeline inspection gauges) are free moving piston-like devices, that are used for inspecting or cleaning pipelines in for example the oil and gas industry. Here they are used for onshore and offshore pipelines, where they are propelled by the production fluids. A better control of the velocity of the pig in the pipeline can be achieved by...

Numerical Study of Flow around Bypass Pigs

In the oil and gas industry, pipeline networks are used to transport the production fluids from wells to production plants. During normal operation, the pipelines need regular cleaning and inspection. Typically, the pipeline maintenance is performed by pigging, which refers to using devices known as “pigs ”(Pipeline Inspection Gauges) to perform...

Oblique Particle-Wall Collisions in a Viscous Fluid

Interaction of particles in a viscous fluid with a wall and with other particles is often observed in phenomena like sedimentation, erosion and filtration processes. With the increasing computational power there is now the possibility of simulating such particle-laden flows from a micro-scale perspective by direct application of no-slip/no...

Turbulence in the wake of a roughness patch

Little research was done in the past concerning the propagation of three dimensional effect in shallow wake flow caused by a roughness patch. Today’s research on related subjects is dominated by emerging obstructions in shallow water where the flow can be assumed as (quasi) two dimensional. However the relevance of a submerged obstruction with...

Self-Sustaining Mechanisms in Wall Bounded Turbulence: Merging & auto-generation of vortices

For channel flow, we explore how a hairpin eddy may reach a threshold strength required to produce additional hairpins by means of auto-generation. This is done by studying the evolution of two eddies with different initial strengths (but both below the threshold strength), initial sizes and initial stream-wise spacing between them. The...