Response of Non-premixed Jet Flames to Blast Waves

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Aravind, Akhil, Vadlamudi, Gautham, Basu, Saptarshi
Format: Preprint
Published: 2023
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866918286661255168
author Aravind, Akhil
Vadlamudi, Gautham
Basu, Saptarshi
author_facet Aravind, Akhil
Vadlamudi, Gautham
Basu, Saptarshi
contents The work investigates the response dynamics of non-premixed jet flame to blast waves that are incident along the jet axis. In the present study, blast waves, generated using the wire-explosion technique, are forced to sweep across a non-premixed jet flame that is stabilised over a nozzle rim positioned at a distance of 264 mm from the source of blast generation. The work spans a wide range of fuel jet Reynolds numbers ($Re$) and incident blast wave Mach numbers ($M_{s,r}$). The interaction imposes a characteristic flow field over the jet flame, marked by a sharp discontinuity followed by a decaying profile and a delayed second spike. The second spike in the flow field profile corresponds to the induced flow that follows the blast front. While the response of the flame to the blast front was minimal, it was found to detach from the nozzle rim and lift off following the interaction with the induced flow. Subsequently, the lifted flame was found to re-attach back at the nozzle or extinguish, contingent on the operating $Re$ and $M_{s,r}$. Alongside flame lift-off, flame tip flickering was aggravated under the influence of the induced flow. A simplified theoretical model extending the vorticity transport equation was developed to estimate the change in flickering timescales and length scales owing to the interaction with the induced flow. The observed experimental trends were further compared against theoretical predictions from the model.
format Preprint
id arxiv_https___arxiv_org_abs_2312_04878
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Response of Non-premixed Jet Flames to Blast Waves
Aravind, Akhil
Vadlamudi, Gautham
Basu, Saptarshi
Fluid Dynamics
Applied Physics
The work investigates the response dynamics of non-premixed jet flame to blast waves that are incident along the jet axis. In the present study, blast waves, generated using the wire-explosion technique, are forced to sweep across a non-premixed jet flame that is stabilised over a nozzle rim positioned at a distance of 264 mm from the source of blast generation. The work spans a wide range of fuel jet Reynolds numbers ($Re$) and incident blast wave Mach numbers ($M_{s,r}$). The interaction imposes a characteristic flow field over the jet flame, marked by a sharp discontinuity followed by a decaying profile and a delayed second spike. The second spike in the flow field profile corresponds to the induced flow that follows the blast front. While the response of the flame to the blast front was minimal, it was found to detach from the nozzle rim and lift off following the interaction with the induced flow. Subsequently, the lifted flame was found to re-attach back at the nozzle or extinguish, contingent on the operating $Re$ and $M_{s,r}$. Alongside flame lift-off, flame tip flickering was aggravated under the influence of the induced flow. A simplified theoretical model extending the vorticity transport equation was developed to estimate the change in flickering timescales and length scales owing to the interaction with the induced flow. The observed experimental trends were further compared against theoretical predictions from the model.
title Response of Non-premixed Jet Flames to Blast Waves
topic Fluid Dynamics
Applied Physics
url https://arxiv.org/abs/2312.04878