CFD for Regulations, Codes and Standards

1
CFD for Regulations, Codes and Standards

• A.G. Venetsanos
• National Centre for Scientific Research
  Demokritos, Greece
• A. Kotchourko
• Research Centre Karlsruhe, Germany
• C.D. Moen
• Sandia National Laboratories, US

2
Presentation Outline

• It will be shown that CFD is increasingly applied
  to provide the necessary support to RCS
  development
• EIHP-2 project
• HyApproval project
• HyPer project
• It will be shown that CFD tools are increasingly
  validated against H2 dispersion/combustion
  phenomena
• HySafe project
• ICHS-2 Session 1
• What we are going to see/listen
• Venetsanos et al. (ICHS-2, 2007)
• An Inter-Comparison Exercise On the Capabilities
  of CFD Models to Predict the Short and Long Term
  Distribution and Mixing of Hydrogen in a Garage

3
EIHP2 project CGH2 bus in a city
CFD applications
LFL clouds
Release of 40 kg H2 (168 kg CH4) through 4 outlet
vents at the top of the bus (Stockholm accident
site)
H2, 20MPa, 10.9s, 12.1 kg
CH4, 20MPa, 7.9s
Urban site (Stockholm) showing assumed bus
location
H2, 70MPa, 5.2s, 18.5 kg
H2, 35MPa, 7.7s, 14.7 kg
Bus storage system
Taken from Venetsanos et al. (2007) J. Loss
Prevention in the Process Industry, In Press
4
EIHP2 project CGH2 bus in tunnel
CFD applications
LFL clouds
Release of 40 kg H2 (168 kg CH4) through 4 outlet
vents at the top of the bus
CH4, 20MPa, 40s, 1756m3, 110kg
H2, 20MPa, 40s, 2358m3, 32.4kg
H2, 35MPa, 30s, 2180m3, 32.5kg
Taken from Venetsanos et al. (2007) J. Loss
Prevention in the Process Industry, In Press
5
HyApproval project Examined scenarios
CFD applications
Shell-HSL experimental site (2006)

• Dispenser rupture of dispensing line (CGH2 35
  and 70 MPa, LH2)
• Trailer Hose disconnection during discharge
  (CGH2 20 MPa, LH2)

Luxemburg CGH2 site
Washington DC, LH2 site
Taken from HyApproval Deliverable 4.6, 2007
6
HyApproval project LH2 dispenser leak
CFD applications
267g LH2 released in 5 seconds (hose id 8mm)
Predicted LFL clouds at 5 sec
5 m/s wind at 10m height
South wind
North wind
Stagnant
West wind
East wind
Taken from HyApproval, NCSRD-JRC report, 2007
7
CFD applications
HYPER project Barrier wall design

• Jet flame experiments are used to validate CFD
  methodology for jet flames from high-pressure
  sources.
• CFD calculations are used characterize
  consequences of unintended releases.
• Barrier walls are a potential mitigation strategy
  for jet releases.

Fuego 3-D RANS simulation of H2 Jet Flame Wall
Impingement
Sandia/SRI H2 Jet Flame Wall Impingement Test
(2500 psi)
Taken from Houf et al., 2nd ICHS, 2007
8
Hyper project Fuel Cell Leak
CFD applications
Fuel cell located inside naturally ventilated
test facility
14.8g H2 released in 60 seconds
Naturally Ventilated Test Facility (CVE)
Location and Interior of Fuel Cell
9
HySafe project Dispersion CFD benchmarking
10
HySafe project Combustion CFD benchmarking
Main parameters important from the point of view
of safety analysis
11
Conclusions

• CFD is increasingly applied for H2 safety studies
  and RCS support
• Main reasons
• CFD has the ability to treat complex scenarios,
  which simpler integral tools cannot handle
• CFD cost is relatively lower than experiments
• CFD tools present generally realistic simulation
  times
• CFD tools/models are increasingly validated
  against H2 dispersion/combustion phenomena

12
ICHS-2 Session-1 Contents

• CFD applications
• Analysis of naturally ventilated h2 from
  buildings, Barley et al.
• CFD simulations of h2 release and dispersion
  inside the storage room of a HRS, Papanikolaou
  and Venetsanos
• Simulation of detonation after an accidental h2
  release in enclosed envirnments, B?dard- Tremblay
  et al.
• CFD simulation study to investigate the risk from
  h2 vehicles in tunnels, Hansen et al.
• High pressure h2 jets in the presence of a
  surface, Benard et al
• CFD validation
• HYSAFE SBEP-V3 results, Venetsanos et al
• HYSAFE SBEP-V5 results, Jordan et al
• Validation of CFD calculations against ignited
  impinging jet experiments, Middha et al.
• Numerical study of spontaneous ignition of
  pressurized h2 release into air, Xu et al.
• CFD modelling of h2 dispersion experiments for
  SAE J2578 test methods development, Tchouvelev et
  al.
• Experimental work
• Processes of the formation of large unconfined
  clouds following a massive spillage of liquid
  hydrogen on the ground, Proust et al.
• Experimental study of jet-formed hydrogen-air
  mixtures and pressure loads from their
  deflagrations in low confined surroundings,
  Friedrich et al.
• Experimental and numerical investigation of h2
  Gas Auto-Ignition, Golub et al
• Unintended Releases of hydrogen, Houf et al