Should we care about the level of detail in trees when running urban microscale simulations?

Due to lack of information and long geometry generation times, tree geometries are usually oversimplified or even ignored in Computational Fluid Dynamic (CFD) simulations that predict wind and pollutant dispersion in urban areas. Nevertheless, trees are known to impact local wind patterns and air quality levels. Thus, in this paper we explore...

An MTI-Like Approach for Interference Mitigation in FMCW Radar Systems

Mutual interference between automotive frequency-modulated continuous-wave (FMCW) radar systems has been a concern over recent years. Several interference mitigation (IM) techniques have been proposed to mitigate this phenomenon, which is deemed to grow in severity as more systems are deployed on the road. In this article, an inexpensive...

Ventilation and thermal conditions in secondary schools in the Netherlands: Effects of COVID-19 pandemic control and prevention measures

During the COVID-19 pandemic, the importance of ventilation was widely stressed and new protocols of ventilation were implemented in school buildings worldwide. In the Netherlands, schools were recommended to keep the windows and doors open, and after a national lockdown more stringent measures such as reduction of occupancy were introduced. In...

Assessing Indoor Air Quality and Ventilation to Limit Aerosol Dispersion—Literature Review

The COVID-19 pandemic highlighted the importance of indoor air quality (IAQ) and ventilation, which researchers have been warning about for years. During the pandemic, researchers studied several indicators using different approaches to assess IAQ and diverse ventilation systems in indoor spaces. To provide an overview of these indicators and...

Validation of different Eulerian and Lagrangian solvers of aerosol dispersion in indoor spaces

The corona pandemic accelerated a lot of studies about aerosol dispersion and different aerosol-generating tasks ranging in intensity from sneezing to breathing. Both measurements and numerical simulations were used to understand the behaviour of aerosols. For numerical simulations, Computational Fluid Dynamic (CFD) simulations were used;...

Assessing Indoor Air Quality and ventilation to limit the spread of airborne pathogens – a review

The corona pandemic underlined a lack of Indoor Air Quality (IAQ) and<br/>ventilation. Consequently, to limit the spread of the virus, researchers explored several indicators that, through different approaches, assess IAQ and ventilation performance in indoor spaces. This paper gives an overview of those indicators and assessment methods used to...

Using Landsat land surface temperature as a proxy for air temperature in urban settings: Experiments in the Netherlands

Understanding the UHI effect in any city requires high-resolution temperature data. This data is often difficult to obtain as cities usually have only a few ground sensors, leaving large data gaps. To fill these gaps, we compare Landsat-derived land surface temperature (LST) with air temperature (Tair) measurements from urban weather stations in...

Effects of COVID-19 measures on ventilation in secondary schools in the Netherlands

During the COVID-19 pandemic, the importance of ventilation for ensuring occupants’ health was widely stressed, especially for densely occupied places such as schools (Ding et al, 2022). Correspondingly, new protocols of ventilation were implemented in school buildings among many countries and regions. In the Netherlands, school classrooms were...

Towards automatic reconstruction of 3D city models tailored for urban flow simulations

In the computational fluid dynamics simulation workflow, the geometry preparation step is often regarded as a tedious, time-consuming task. Many practitioners consider it one of the main bottlenecks in the simulation process. The more complex the geometry, the longer the necessary work, meaning this issue is amplified for urban flow simulations...

The impact of level of detail in 3d city models for cfd-based wind flow simulations

Climate change and urbanization rates are transforming urban environments, making the use of 3D city models in computational fluid dynamics (CFD) a fundamental ingredient to evaluate urban layouts before construction. However, current geometries used in CFD simulations tend to be built by CFD experts to test specific cases, most of the times...

Inclusion of Building-Resolving Capabilities Into the FastEddy® GPU-LES Model Using an Immersed Body Force Method

As a first step toward achieving full physics urban weather simulation capabilities within the resident-GPU large-eddy simulation (LES) FastEddy® model, we have implemented and verified/validated a method for explicit representation of building effects. Herein, we extend the immersed body force method (IBFM) from Chan and Leach (2007, https:/...

Bepalen luchtverontreiniging door verkeer met behulp van 3D-geo-informatie

Eerder publiceerden we in Geo-Info over onze methode om 3D-data zoals nodig in geluidsimulaties automatisch te genereren uit landsdekkende gegevens zoals BAG, BGT en hoogtepunten [1]. Deze geluidsimulaties zijn gebaseerd op gestandaardiseerde rekenvoorschriften voor geluids- belasting. Ook het berekenen van de luchtkwaliteit ten gevolge van...