a.horvat - mathematical modelling and engineering analysis

Airflow and droplet dynamics following a human cough

The recent COVID-19 pandemic prompted the need for deeper understanding of airflow and droplet dynamics during a coughing sequence. The transport of droplets influences the spread of coronavirus and determines implementation of preventive measures ...

Fire safety analysis for an offshore platform using CFD modelling

Simulation analysis of a large scale gas release on an offshore platform and the subsequently ensuing fire was conducted to determine the size of the fire ball and the resulting heat load distribution on the surrounding structure. The animation shows flammability limits and the fire region ...

Performance assessment of a rotary dryer

In the energy-from-waste power plants the moisture content in the feedstock reduces thermodynamic efficiency of the conversion process. For that reason, a certain degree of feedstock drying is necessary. An algebraic and a CFD/DEM model of the drying process was developed ...

Design optimisation of Marshall fertilizer spreader

A numerical model was used as a design tool to test different design iterations of the Marshall fertilizer spreader and to carry out sensitivity analyses prior to physical prototyping and validation. Use of the numerical model allowed for a better understanding of the parameters ...

Improving performance of a novel laparoscope attachment

During a minimally invasive procedure, a laparoscope's lens has to be maintained clean as the adequate vision is crucial for a safe surgical procedure. Cipher Surgical developed a novel laparoscope attachment - OpClear® that directs an 'on demand' jet of CO2 across the lens ...

Heat transfer improvement in fire tubes

Installation of a helix in fire tubes may have a beneficial effect due to increased mixing. For that reason different configurations of a static and a moving helix were analysed. The water flow in the annular channel was modelled using the heterogeneous two-phase model ...

Draining of ITER NBDI duct liner side panels by blow-out

Many components of ITER Neutral Beam (NB) will be subjected to significant heat loads, and therefore require active water cooling during their operation. A number of analysis projects had been conducted to demonstrate success of the blow-out sequence using the available nitrogen pressure supply ...

Modelling of solidification processes in a baby bottle warmer

A novel self-heating baby bottle was developed. It uses an integral warming plug as the source of heat. The plug contains sodium acetate, which releases heat when a user triggers the solidification reaction of the sub-cooled liquid. A CFD model that included a solidification reaction in the warmer ...

Simulation analysis of backdraft development

Backdraft is one of the most hazardous events related to under-ventilated fires. It is caused by fuel vapour being generated after a fire is extinguished, or reduced in intensity by oxygen starvation, and the subsequent introduction of fresh oxygen, for example by opening of a door ...

Validation of flashover CFD model against experimental data

From the fire-fighting perspective, flashover is a critical stage of fire growth. Namely, when flashover takes place, the probability of survival of occupants rapidly decreases. A Computational Fluid Dynamics (CFD) model was developed to simulate flashover behaviour. It describes ...

Wall heat flux analysis for ventilation controlled fire in an enclosure

Transient numerical simulations of a fire in an enclosure (1/3 the ISO room size) were performed to develop and to validate a transient semi-analytical treatment of the heat transfer in the walls. The setup closely followed one of experiments performed by Tofilo et al (2005). As in the experiments ...

CFD analysis of the King's Cross station fire

Simulation analysis of the King's Cross accident in London (1987) was conducted to determine and understand causes for observed fire behaviour and the extent of fatalities in the escalator shaft of the Piccadilly line. An inert fire model was used with the thermal source of 1.6 MW. The fire started in ...

Vortex shedding from a magnetic drive read-and-write head

Numerical simulation techniques were used to investigate the flow induced by a rotating magnetic drive in an experimental test facility. The work initially examined the global flow within the disk system before focusing on the flow local to the read-and-write head unit ...

Simulation of breaking waves and associated loads

Offshore wind farms located in a shallow water environment and in areas prone to hurricanes may experience extreme breaking waves. Although little is known about their characteristics, breaking waves may represent a dominant load that a wind turbine structure is subjected to over its design lifetime ...

CFD modelling of LNG spills, their evaporation and dispersion

Liquefied Natural Gas (LNG) is becoming increasingly popular way of transporting otherwise gaseous fuel over large distances. Much of this transport is conducted using LNG ocean carriers. As part of the engineering design and safety assessment process, it is important to understand ...

Thermal loads on the reactor vessel during a severe accident

In order to investigate cooling of core melt in a lower plenum during severe accident conditions, a numerical model of natural convection due to volumetric heat generation was prepared. Four different geometries were taken into consideration. As our primary concern was ...

Loss of Vacuum Accident (LOVA) analysis for JET fusion reactor

Joint European Torus (JET) has been planning a tritium operation sequence for which some of the safety analyses need to be repeated. In this framework, three different scenarios of Loss of Vacuum Accident (LoVA) require inventory release assessment. The starting event for all investigated scenarios ...