Welcome to the "GraVent DDT database", an open-access platform, which first went online in July 2015. It provides data from experiments on flame acceleration, deflagration-to-detonation transition (DDT) and detonation propagation which were carried out at the GraVent facility at the Technical University of Munich. This set-up is a completely enclosed rectangular laboratory scale explosion channel with a height of 0.06 m, a width of 0.3 m and a variable length of up to 5.4 m. So far the main focus has been placed on hydrogen-air mixtures at initially ambient pressure and temperature. Both conventional data (photodiodes, pressure transducers) and results from optical high-speed measurements (shadowgraphy, 20 kHz OH-PLIF) are provided.
The presented work is funded by the German Federal Ministry of Economic Affairs and Energy (BMWi) on the basis of a decision by the German Bundestag (projects 1501338 and 1501425) which is gratefully acknowledged.
How to Cite the GraVent DDT Database
If you work with our data please cite us as follows:
Boeck, L. R., Katzy, P., Hasslberger, J., Kink, A., & Sattelmayer, T. (2016). The GraVent DDT database. Shock Waves, online first 03/2016
The content of the database is continuously being updated. Please find the update history at the bottom of this page.
If you do not find specific data that you would like to use for your work, please do not hesitate to contact us. Also if you have any questions about the data interpretation, please let us know. Last but not least, we would be glad to hear your feedback on the database and its content.
Background Information on DDT Research at TUM
Our motivation for the investigation of DDT, especially in hydrogen-air mixtures, is based on hydrogen explosion hazards in nuclear reactors. During severe accident scenarios such as loss-of-coolant accidents (LOCA), large amounts of hydrogen can be produced and dispersed inside a nuclear reactor building. Hydrogen mixes with air which forms a flammable mixture. Since potential ignition sources are omnipresent in such facilities, ignition is probable. Depending on the extent of the confining geometry, congestion (obstacles inside the geometry) and mixture composition, flame acceleration may occur. Fast flames pose a severe hazard due to high overpressure (up to about 10 bar, starting from initially ambient pressure). If critical conditions are reached transition to detonation may occur. This violent local process transforms the fast flame (fast deflagration) into a detonation which is typically considered a worst case explosion scenario, causing overpressure of up to about 20 bar. Laboratory scale experiments like the ones presented here help to understand the physics behind flame acceleration, DDT and detonation phenomena. During the past few years research at TUM has been mainly directed towards the effect of spatial concentration gradients on DDT.
22/07/2015 OH-PLIF and shadowgraphy data from transverse concentration gradient experiments uploaded
17/07/2015 OH-PLIF and shadowgraphy data from experiments on homogeneous H2-air mixtures now available
10/07/2015 platform goes online for the first time providing conventional data on dry homogeneous and inhomogeneous H2-air mixtures tested in unobstructed and obstructed configurations, as well as homogeneous mixtures with water mist injection.