Comparison of Deflagration to Detonation Transition (DDT) Criteria with Test Data From Unconfined Ethylene-Air Vapor Cloud Explosion

  • Type:
    Conference Presentation
  • Skill Level:
    Intermediate
  • PDHs:
    0.50

Share This Post:

You will be able to download and print a certificate for these PDH credits once the content has been viewed. If you have already viewed this content, please click here to login.

Deflagration to detonation transitions (DDT) were previously observed in a set of large-scale unconfined vapor cloud explosion (VCE) tests involving ethylene-air mixtures in a moderately congested environment. The test rig congested region was 48 feet long by 12 wide by 6 feet high, with a regular array of vertical circular tubes providing the congestion (pitch-to-diameter ratio of 4.5, area and volume blockage ratios of 22% and 4.1%, respectively). The test rig was configured without any confinement (i.e., no wall or roof sections). The fuel-air mixture completely filled the congested region in these tests, but did not extend beyond it. DDTs were observed at ethylene concentrations ranging from 5.9% (lean) to 9.3% (rich). A comparison has now been made between a DDT criterion established for the FLACS code and this test data. The FLACS DDT criterion utilizes the maximum dimensionless pressure gradient and was established by benchmarking primarily against hydrogen-air tests in confined geometries (i.e., pipes and channels). The comparison with the existing ethylene-air VCE DDT data indicates a different critical value for the maximum dimensionless pressure gradient than that developed based on the confined hydrogen-air tests. Alternative DDT criteria were also explored as part of this work.

Please note that due to the visual quality of this paper, there is no charge for it. The information is still valuable hence we are posting it here.
Presenter(s): 

Checkout

Checkout

Do you already own this?

Log In for instructions on accessing this content.

Pricing

AIChE Members $15.00
AIChE Undergraduate Student Members Free
AIChE Graduate Student Members Free
Non-Members $25.00