OpenFOAM-based CFD Simulation of Hydrogen Dispersion in a V-shaped Roof Compressor Building

Abstract

Hydrogen safety is an important issue in future energy systems, especially for indoor
or semi-conffned facilities where leaked hydrogen may accumulate and form explosive
regions. This study investigates hydrogen dispersion in a compressor building with a
V-shaped roof and upper natural ventilation openings. Computational ffuid dynamics
simulations are carried out using OpenFOAM to analyse the transport and accumulation
of hydrogen after high pressure release. A simpliffed reduced-velocity source based on
the notional nozzle treatment is used to represent the small high pressure leakage source
and reduce the computational cost. Two release directions, upward and downward, are
compared. The results show that the release direction strongly affects the hydrogen
distribution and velocity ffeld inside the building. In the upward release case, hydrogen
is transported rapidly toward the roof region by the initial jet momentum and buoyancy
and then spreads along the sloping roof toward the upper openings. In the downward
release case, hydrogen ffrst moves toward the lower part of the room and then gradually
rises due to buoyancy and indoor recirculation. The upward release has a stronger
inffuence on the roof region, while the downward release is more important for the ffoor
region. Overall, this study shows that roof geometry and release direction are important
factors in indoor hydrogen dispersion. The results can provide a useful reference for
hydrogen safety assessment and ventilation design in similar industrial buildings.

Popular Abstract

Hydrogen is expected to play an important role in future energy systems because it can be used as a clean energy carrier. However, hydrogen also has safety risks. It is colourless and odourless, so it is difficult to detect without sensors. It is also much lighter than air, which means that leaked hydrogen can rise quickly and accumulate near the ceiling. If hydrogen mixes with air in an enclosed space, it may form a flammable or explosive region.
This thesis studies hydrogen dispersion in a compressor building with a V-shaped roof and
upper natural ventilation openings. Compressor buildings are important in hydrogen facilities because compressors, pipes, and valves can be possible leakage sources. The roof shape and the position of ventilation openings may affect how hydrogen moves and where it accumulates.
Computational fluid dynamics, or CFD, was used to simulate hydrogen release inside the
building. The simulations were carried out using OpenFOAM. Two release directions were
compared: upward release and downward release.
The results show that release direction has a clear influence on hydrogen transport. In the
upward release case, hydrogen moves rapidly toward the roof due to the initial jet momentum
and buoyancy. It then spreads along the sloping roof toward the upper openings. In the
downward release case, hydrogen first moves toward the lower part of the room and then
gradually rises due to buoyancy and recirculation.
Overall, this study shows that roof geometry and release direction are important for indoor
hydrogen dispersion. The results can provide useful information for hydrogen safety assessment and ventilation design in similar industrial buildings.

• author: Wang, Shule
• supervisor: Rixin Yu
• organization: Department of Energy Sciences
• course: MVKM05 20261
• year: 2026
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: Hydrogen dispersion, CFD, OpenFOAM, V-shaped roof, compressor building, release direction, natural ventilation.
• report number: ISRN LUTMDN/TMHP-26/5691-SE
• ISSN: 0282-1990
• language: English
• id: 9234947
• date added to LUP: 2026-06-16 09:57:07
• date last changed: 2026-06-16 10:37:53