Numerical Investigation of the Effects of Diffusion Time on the Mechanisms of Transition from a Turbulent Jet Flame to Detonation in a H<sub>2</sub>-Air Mixture
The current study primarily aimed to simulate detonation initiation via turbulent jet flame acceleration in partial-premixed H<sub>2</sub>-air mixtures. Different vertical concentration gradients were generated by varying the duration of hydrogen injection (diffusion time) within an encl...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-11-01
|
| Series: | Fire |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2571-6255/6/11/434 |
| _version_ | 1827639948033916928 |
|---|---|
| author | Mohammad Hossein Shamsaddin Saeid Javad Khadem Sobhan Emami Chang Bo Oh |
| author_facet | Mohammad Hossein Shamsaddin Saeid Javad Khadem Sobhan Emami Chang Bo Oh |
| author_sort | Mohammad Hossein Shamsaddin Saeid |
| collection | DOAJ |
| description | The current study primarily aimed to simulate detonation initiation via turbulent jet flame acceleration in partial-premixed H<sub>2</sub>-air mixtures. Different vertical concentration gradients were generated by varying the duration of hydrogen injection (diffusion time) within an enclosed channel filled with air. H<sub>2</sub>-air mixtures with average hydrogen concentrations of 22.5% (lean mixture) and 30% (near stoichiometric mixture) were investigated at diffusion times of 3, 5, and 60 s. Numerical results show that the vertical concentration gradient significantly influences the early stage of flame acceleration (FA). In the stratified lean mixture, detonation began at all the diffusion times, and comparing the flame-speed graphs showed that a decrease in the diffusion time and an increase in the mixture inhomogeneity speeded up the flame propagation and the jet flame-to-detonation transition occurrence in the channel. In the stratified H<sub>2</sub>-air mixture with an average hydrogen concentration of 30%, the transition from a turbulent jet flame to detonation occurred in all the cases, and the mixture inhomogeneity weakened the FA and delayed the detonation initiation. |
| first_indexed | 2024-03-09T16:51:11Z |
| format | Article |
| id | doaj.art-c472fb8d1abb4033a8dd72c9138fc302 |
| institution | Directory Open Access Journal |
| issn | 2571-6255 |
| language | English |
| last_indexed | 2024-03-09T16:51:11Z |
| publishDate | 2023-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Fire |
| spelling | doaj.art-c472fb8d1abb4033a8dd72c9138fc3022023-11-24T14:41:35ZengMDPI AGFire2571-62552023-11-0161143410.3390/fire6110434Numerical Investigation of the Effects of Diffusion Time on the Mechanisms of Transition from a Turbulent Jet Flame to Detonation in a H<sub>2</sub>-Air MixtureMohammad Hossein Shamsaddin Saeid0Javad Khadem1Sobhan Emami2Chang Bo Oh3Department of Safety Engineering, Pukyong National University, Busan 48513, Republic of KoreaDepartment of Mechanical Engineering, University of Birjand, Birjand 97175615, IranDepartment of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad 8514143131, IranDepartment of Safety Engineering, Pukyong National University, Busan 48513, Republic of KoreaThe current study primarily aimed to simulate detonation initiation via turbulent jet flame acceleration in partial-premixed H<sub>2</sub>-air mixtures. Different vertical concentration gradients were generated by varying the duration of hydrogen injection (diffusion time) within an enclosed channel filled with air. H<sub>2</sub>-air mixtures with average hydrogen concentrations of 22.5% (lean mixture) and 30% (near stoichiometric mixture) were investigated at diffusion times of 3, 5, and 60 s. Numerical results show that the vertical concentration gradient significantly influences the early stage of flame acceleration (FA). In the stratified lean mixture, detonation began at all the diffusion times, and comparing the flame-speed graphs showed that a decrease in the diffusion time and an increase in the mixture inhomogeneity speeded up the flame propagation and the jet flame-to-detonation transition occurrence in the channel. In the stratified H<sub>2</sub>-air mixture with an average hydrogen concentration of 30%, the transition from a turbulent jet flame to detonation occurred in all the cases, and the mixture inhomogeneity weakened the FA and delayed the detonation initiation.https://www.mdpi.com/2571-6255/6/11/434time diffusionmixture inhomogeneitydeflagration to detonation transitionturbulent jet flame |
| spellingShingle | Mohammad Hossein Shamsaddin Saeid Javad Khadem Sobhan Emami Chang Bo Oh Numerical Investigation of the Effects of Diffusion Time on the Mechanisms of Transition from a Turbulent Jet Flame to Detonation in a H<sub>2</sub>-Air Mixture Fire time diffusion mixture inhomogeneity deflagration to detonation transition turbulent jet flame |
| title | Numerical Investigation of the Effects of Diffusion Time on the Mechanisms of Transition from a Turbulent Jet Flame to Detonation in a H<sub>2</sub>-Air Mixture |
| title_full | Numerical Investigation of the Effects of Diffusion Time on the Mechanisms of Transition from a Turbulent Jet Flame to Detonation in a H<sub>2</sub>-Air Mixture |
| title_fullStr | Numerical Investigation of the Effects of Diffusion Time on the Mechanisms of Transition from a Turbulent Jet Flame to Detonation in a H<sub>2</sub>-Air Mixture |
| title_full_unstemmed | Numerical Investigation of the Effects of Diffusion Time on the Mechanisms of Transition from a Turbulent Jet Flame to Detonation in a H<sub>2</sub>-Air Mixture |
| title_short | Numerical Investigation of the Effects of Diffusion Time on the Mechanisms of Transition from a Turbulent Jet Flame to Detonation in a H<sub>2</sub>-Air Mixture |
| title_sort | numerical investigation of the effects of diffusion time on the mechanisms of transition from a turbulent jet flame to detonation in a h sub 2 sub air mixture |
| topic | time diffusion mixture inhomogeneity deflagration to detonation transition turbulent jet flame |
| url | https://www.mdpi.com/2571-6255/6/11/434 |
| work_keys_str_mv | AT mohammadhosseinshamsaddinsaeid numericalinvestigationoftheeffectsofdiffusiontimeonthemechanismsoftransitionfromaturbulentjetflametodetonationinahsub2subairmixture AT javadkhadem numericalinvestigationoftheeffectsofdiffusiontimeonthemechanismsoftransitionfromaturbulentjetflametodetonationinahsub2subairmixture AT sobhanemami numericalinvestigationoftheeffectsofdiffusiontimeonthemechanismsoftransitionfromaturbulentjetflametodetonationinahsub2subairmixture AT changbooh numericalinvestigationoftheeffectsofdiffusiontimeonthemechanismsoftransitionfromaturbulentjetflametodetonationinahsub2subairmixture |