Imperial College London
Van Reeuwijk Lab
From city streets to cloud edges, we study how turbulence carries heat, particles, and pollutants and how this impacts the environment.
We develop the numerical, theoretical, and data-driven tools needed to study environmental turbulence: DNS and LES, reduced-order models, data assimilation, machine-learning surrogates, and the open-source urban LES code uDALES.
Interactive demos
Run a simulation
We enjoy working with models and the tools around them. The demos below are a taster of the kind of problems we study — runnable in your browser, drawn directly from the lab's research.
Wind in urban terrain
Place rectangular buildings on a top-down city plan, rotate the wind direction, and watch the particle field show channelling, wakes, and stagnation zones.
Gravity currents — the lock-release experiment
Pour something dense into something lighter and it doesn't sit still — it races along the bottom in a head-and-tail structure with a remarkably steady speed. Compare the simulated current with a two-layer shallow-water prediction.
Rayleigh–Bénard convection — patterns from heat
Heat the bottom of a fluid layer, cool the top, and watch patterns emerge. Adjust the Rayleigh number to walk from conduction through cells to soft turbulence.
How urban surfaces respond to a diurnal cycle
A 1D surface energy balance running live in the browser — pick a material, change the forcing, watch the heat wave penetrate the wall.
Surface energy balance, face by face
How uDALES resolves the energy budget on every roof, wall and pavement in an urban block — and how we read those outputs with the udbase Python tools.
Patterns from chaos — symmetric fractals
A simple complex map iterated millions of times produces intricate, symmetry-respecting patterns — a small window onto the kind of scale-invariant structure that pervades turbulent flows.
Latest publications
All →- Parameter investigation for urban surface‐energy balance: A large‐eddy simulation studyQuarterly Journal of the Royal Meteorological Society · 2026
- Entrainment and detrainment statistics of a stationary shallow cumulus cloudQuarterly Journal of the Royal Meteorological Society · 2025
- Impact of Data Assimilation Frequency and Observation Location in Thermal Effluent Modeling for Coastal WatersEarth and Space Science · 2025
- Large-eddy simulation of a diurnal cycle in a coastal urban environmentBuilding and Environment · 2025
- Microscale to neighbourhood scale: Impact of shading on urban climateBuilding and Environment · 2025
Updates
- Launching the new Van Reeuwijk Lab website4 May 2026
Maarten's LinkedIn post on the new lab website — a decade of planning brought to life in a couple of days using agentic software engineering, pulling content directly from ORCID, arXiv, GitHub, and Zenodo.
- Urban Surface-Energy Balance Study by Chris Wilson et…15 Apr 2026
We are pleased to share our latest work on the urban surface-energy balance, led by former PhD student (soon to be Dr) Chris Wilson with collaborators Athanasios Paschalis (University of Cyprus), Sylvia Bohnenstengel (Met Office) and Jon Shonk (Met Office).
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- Urban vegetation and pollutant dispersion18 Dec 2025
Maarten's LinkedIn post on a new open-access Atmospheric Environment paper about trees and pollutant dispersion in street canyons.