Stability analysis of thermodiffusively unstable counterflow lean premixed hydrogen flames
Fuente:
arXiv
Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866916933713002496 |
|---|---|
| author | Porcarelli, Alessandro Lapenna, Pasquale Eduardo Creta, Francesco Langella, Ivan |
| author_facet | Porcarelli, Alessandro Lapenna, Pasquale Eduardo Creta, Francesco Langella, Ivan |
| contents | This study investigates the effect of increasing strain rate on thermodiffusively unstable, lean premixed hydrogen flames in a 2D counterflow configuration through detailed-chemistry numerical simulations for the first time. The analysis of transient flame dynamics without imposed perturbations reveals that a steady-state flame front is achieved only when the strain rate exceeds a certain threshold. Below this threshold, the flame exhibits unstable oscillatory behavior. When subjected to a range of perturbation wavelengths, the flame front exhibits an exponentially increasing wavelength over time, driven by the flame-tangential velocity component, with the applied strain rate acting as the amplification factor. It is shown that any perturbation is damped at sufficiently high applied strain rate conditions after a transient phase. At these high strain regimes, the growth rate transient follows a characteristic onset that depends uniquely on the initial perturbation wavelength and exhibits a linear dependence on the applied strain rate. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2509_04197 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Stability analysis of thermodiffusively unstable counterflow lean premixed hydrogen flames Porcarelli, Alessandro Lapenna, Pasquale Eduardo Creta, Francesco Langella, Ivan Fluid Dynamics This study investigates the effect of increasing strain rate on thermodiffusively unstable, lean premixed hydrogen flames in a 2D counterflow configuration through detailed-chemistry numerical simulations for the first time. The analysis of transient flame dynamics without imposed perturbations reveals that a steady-state flame front is achieved only when the strain rate exceeds a certain threshold. Below this threshold, the flame exhibits unstable oscillatory behavior. When subjected to a range of perturbation wavelengths, the flame front exhibits an exponentially increasing wavelength over time, driven by the flame-tangential velocity component, with the applied strain rate acting as the amplification factor. It is shown that any perturbation is damped at sufficiently high applied strain rate conditions after a transient phase. At these high strain regimes, the growth rate transient follows a characteristic onset that depends uniquely on the initial perturbation wavelength and exhibits a linear dependence on the applied strain rate. |
| title | Stability analysis of thermodiffusively unstable counterflow lean premixed hydrogen flames |
| topic | Fluid Dynamics |
| url | https://arxiv.org/abs/2509.04197 |