主催: The Japan Society of Mechanical Engineers
会議名: 第30回 原子力工学国際会議(ICONE30)
開催日: 2023/05/21 - 2023/05/26
During a severe accident, containment integrity is threatened by a possible hydrogen explosion. Hydrogen flame can be accelerated or quenched depending on the mixture, turbulence, and geometry. At present, turbulence and steam effects on flame acceleration, deceleration, and quenching are not well reproduced by the combustion models usually implemented in the tools relevant to nuclear safety.
flameFoam is our custom open-source turbulent premixed combustion solver for OpenFOAM framework. It was developed to perform fast and adequately accurate technical simulations using RANS and TFC modeling approaches. However, in such a framework, there is no accepted flame quenching model. The most common model is based on the flame stretch effect and estimates the probability that the stretching will not quench the flame. This model is parametrized by the critical rate of strain.
This model has been recently implemented in flameFoam. This paper presents the initial validation of the implemented model based on ENACCEF facility experiments available from the SARNET2 project. Results obtained with and without quenching modeling are presented and compared. The sensitivity of the obtained results to the critical rate of strain is examined in the simulations with flame quenching. Initial validation shows that the implemented model shows high sensitivity to the critical rate of strain parameter, however, this parameter is not well defined and can be used to fit the simulation results. Implemented model tends to quench the flame in the high turbulence areas, mainly the acceleration tube of the ENACCEF facility, but underestimates the quenching intensity at the exit to the dome. This results in unsatisfactory simulations outcome, showing that quenching modeling under severe accident-relevant conditions in the given framework requires further development.