This work describes a modelling approach to SARS-CoV-2 dispersion based on experiments. The main goal is the development of an application integrated in Ansys Fluent to enable computational fluid dynamics (CFD) users to set up, in a relatively short time, complex simulations of virion-laden droplet dispersion for calculating the probability of SARS-CoV-2 infection in real life scenarios. The software application, referred to as TU Delft COVID-app, includes the modelling of human expiratory activities, unsteady and turbulent convection, droplet evaporation and thermal coupling. Data describing human expiratory activities have been obtained from selected studies involving measurements of the expelled droplets and the air flow during coughing, sneezing and breathing. Particle Image Velocimetry (PIV) measurements of the transient air flow expelled by a person while reciting a speech have been conducted with and without a surgical mask. The instantaneous velocity fields from PIV are used to determine the velocity flow rates used in the numerical simulations, while the average velocity fields are used for validation. Furthermore, the effect of surgical masks and N95 respirators on particle filtration and the probability of SARS-CoV-2 infection from a dose-response model have also been implemented in the application. Finally, the work includes a case-study of SARS-CoV-2 infection risk analysis during a conversation across a dining/meeting table that demonstrates the capability of the newly developed application.

@en

Design of floating terminals requires integrated approach as it requires multi-machine systems. Master students in mechanical engineering from Multi-machine engineering track at TU Delft were assigned design of floating terminals as part of their Integration Project course. Each of seven student groups designed a specific piece of port equipment that was later integrated in the floating terminal design. This required different design approaches: a detailed one for the equipment design (structure and functionality), and conceptual one for the floating terminal (overall layout and operational strategy). This encouraged the students to develop skills needed in real working environment, managing the design process and decision making within their own group and discussing setup, basic designs and dimensions together with the other groups. Owning their design throughout the entire process was in particularly important to the students, as they wanted other groups to use their equipment design. For the terminal design they needed to make a case for the feasibility of the floating terminal, including logistics simulations and cost. This paper shows the benefits of integrated design project course, the methods used for its implementation, as well as addressing current challenges of online group design work and supervision. Being part of European Horizon 2020 project motivated the students even more to contribute to an overall bigger objective.

@en

Although the interpersonal distance represents an important parameter affecting the risk of infection due to respiratory viruses, the mechanism of exposure to exhaled droplets remains insufficiently characterized. In this study, an integrated risk assessment is presented for SARS-CoV-2 close proximity exposure between a speaking infectious subject and a susceptible subject. It is based on a three-dimensional transient numerical model for the description of exhaled droplet spread once emitted by a speaking person, coupled with a recently proposed SARS-CoV-2 emission approach. Particle image velocimetry measurements were conducted to validate the numerical model. The contribution of the large droplets to the risk is barely noticeable only for distances well below 0.6 m, whereas it drops to zero for greater distances where it depends only on airborne droplets. In particular, for short exposures (10 s) a minimum safety distance of 0.75 m should be maintained to lower the risk below 0.1%; for exposures of 1 and 15 min this distance increases to about 1.1 and 1.5 m, respectively. Based on the interpersonal distances across countries reported as a function of interacting individuals, cultural differences, and environmental and sociopsychological factors, the approach presented here revealed that, in addition to intimate and personal distances, particular attention must be paid to exposures longer than 1 min within social distances (of about 1 m).

@en

Wind turbine industry is growing and future predictions are promising. However, a shortage of installation vessels could influence this growth in offshore wind industry. Commonly, wind turbines are installed in components using a jack-up vessel. Occasionally, wind turbines are installed fully assembled. Lifting above the wind turbine is not necessarily for fully assembled wind turbine installation due to the center of gravity of a fully assembled wind turbine. Wind turbines can be installed fully assembled using cranes in twin lift configuration to reduce required lifting capacities. The flexibility and scalability of the vessel depends on the location of the cranes on the vessel. Different vessels can install wind turbines with their advantages and disadvantages. A morphological analysis in combination with a comparison are used to identify promising solutions for fully assembled wind turbine installation. One new concept, the PWT installation vessel, shows overall improvement in installation rates. This solution, developed by the author of this paper, is proposed for flexible and scalable fully assembled wind turbine installation. Furthermore, this specific vessel is usable for other installation activities too.

@en

Design of floating terminals requires integrated approach as it requires multi-machine systems. Master students in mechanical engineering from Multi-ma-chine engineering track at TU Delft were assigned design of floating terminals as part of their Integration Project course. Each of seven student groups designed a specific piece of port equipment that was later integrated in the floating terminal design. This required different design approaches: a detailed one for the equipment design (structure and functionality), and conceptual one for the floating terminal (overall layout and operational strategy). This encouraged the students to develop skills needed in real working environment, managing the design process and deci-sion making within their own group and discussing setup, basic designs and dimen-sions together with the other groups. Owning their design throughout the entire pro-cess was in particularly important to the students, as they wanted other groups to use their equipment design. For the terminal design they needed to make a case for the feasibility of the floating terminal, including logistics simulations and cost. This paper shows the benefits of integrated design project course, the methods used for its implementation, as well as addressing current challenges of online group design work and supervision. Being part of European Horizon 2020 project motivated the students even more to contribute to an overall bigger objective.@en