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CEA Garage Tests 1 To 5

Experiment ID SBEP-V21 : CEA Garage free volume dispersion tests 1 to 5
Short description Dispersion experiments performed in the experimental set-up GARAGE located at CEA/Saclay (F). Five tests were performed in a free volume condition and consisted in vertical release of helium in the enclosure. The experimental enclosure is of rectangular shape with interior dimensions of 5.76 m (Length) x 2.96 m (Width) x 2.42 m (Height). The internal volume of GARAGE is 40.92 m3. The maximum uncertainty in GARAGE volume calculation is of the order of 0.5 %.

The garage is equipped with a door for technical access in the back (2020mm x 810mm), and a tilting door on the front side (2320mm x 1990mm). A 200mm diameter vent is located on the back wall at 160mm from the floor and 1480mm from the side. This bottom vent is used to avoid pressure increase during the release. Thus, it is opened during the injection and closed after. Another vent is located near the top of the same wall, at 160 mm from the ceiling and 1480mm from the side. This one is closed and sealed for all the experiments presented here. When sealed to the maximum, the enclosure natural ventilation has been measured at 0.01ACH. During the injection, the bottom vent is open so that the ACH should be higher. However, a measurement of the concentration at the exit shows that during this stage, no helium flow out of the garage.

What phenomena were studied These tests allow to study the formation of a stratified zone in a enclosure for different release conditions. The main phenomena governing the stratification creation are assumed to be the entrainment in the jet and plume and the impingement at the ceiling and on lateral walls.
What phenomena / effects can be studied Reynolds and Richarson numbers were varied at the release. And concentration measured at different locations (about 60 katharometers) versus time.
Test nTest1Test2Test3Test4Test5
X Source28802880288028802880
Y Source14801480148014801480
Z Source220220220220220
D (mm)20,720,720,7529,7
Q (Nl/min)66866,86681818
Injection time (s)12130050037403740
Injected volume (Nl)1347334556711221122
T (C)21,624,019,223,924,1
Q (m^3/s)1,20E-021,21E-031,19E-023,26E-043,26E-04
Q (g/s He)1,990,1991,990,05360,0536
U (m/s)35,703,6035,4116,610,47
Instrumentation The reference point for the measurement of the position of the sensors is located at the floor on the left corner of the front wall. The front wall is that with the tilting door and we consider the left side while looking at the front wall from the exterior. The locations of the sensors are given in the specification document.
Test variables The test variables are the volume fraction of hydrogen for each sensor. A relevant variable to compare is the volume average of concentration for each vertical "slice". This can be compared to the average of experimental concentrations.
Data description / Data completeness 5 excel files are provided giving the horizontal average of sensor's volume fraction versus time.
Data availability
Source of data / Reference 5 Experimental excel files available to Hysafe partners. Results were partly published in ICHS2 by S.Gubtay.
Why were chosen Well controled initial and boundary conditions. Experiments were reproduced to assess the repeatability.
Relevance to the project purposes Assess models and codes against stratification prediction in enclosures for different flow conditions.
Experimental data
Results of simulations Presentation of M.Bucci at WP6 Meeting in Karsruhe, CEA internal report available and presentation from S.Benteboula to be given at ICHS3.
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Page last modified on February 03, 2009, at 02:33 PM