Deflagration tests in a closed chamber were performed to investigate the temperature influence on the dynamic behavior and flame acceleration of spherically expanding hydrogen flames. The dynamic behavior of hydrogen flames was observed by using high speed Schlieren photography, and the flame radius and propagation velocity were measured by analyzing Schlieren images. When flame radius was small, smooth flames were found, where flame stretch affected propagation velocity strongly. We obtained the propagation velocity of a flat flame and the Markstein length through the correlation between flame stretch and propagation velocity of a spherical flame. When flame radius was large, cellular flames were found and flame acceleration appeared. We obtained the increment coefficient of propagation velocity and the critical flame radius corresponding to the onset of flame acceleration. As the initial temperature became higher, the dynamic behavior of hydrogen flames weakened, and then the increment coefficient of propagation-velocity ratio decreased. This was because of the weakness of intrinsic instability. In addition, the proposed model on flame acceleration, taking account of the initial temperature, was good agreement with the experimental results.
August 28, 2017 There had been a service stop from Aug 28‚ 2017‚ 1:50 to Aug 28‚ 2017‚ 10:08(JST) (Aug 27‚ 2017‚ 16:50 to Aug 28‚ 2017‚ 1:08(UTC)) . The service has been back to normal.We apologize for any inconvenience this may cause you.
July 31, 2017 Due to the end of the Yahoo!JAPAN OpenID service, My J-STAGE will end the support of the following sign-in services with OpenID on August 26, 2017: -Sign-in with Yahoo!JAPAN ID -Sign-in with livedoor ID * After that, please sign-in with My J-STAGE ID.
July 03, 2017 There had been a service stop from Jul 2‚ 2017‚ 8:06 to Jul 2‚ 2017‚ 19:12(JST) (Jul 1‚ 2017‚ 23:06 to Jul 2‚ 2017‚ 10:12(UTC)) . The service has been back to normal.We apologize for any inconvenience this may cause you.
May 18, 2016 We have released “J-STAGE BETA site”.
May 01, 2015 Please note the "spoofing mail" that pretends to be J-STAGE.