Study of elevated- and ground pool fire flame horizontal lengths in cross airflows: Air entrainment change due to Coand a effect

被引：11

作者：

Chen, Yuhang ^{[1
]}

Fukumoto, Kazui ^{[2
]}

Zhang, Xiaolei ^{[1
]}

Lin, Yujie ^{[1
]}

Tang, Fei ^{[1
]}

Hu, Longhua ^{[1
]}

机构：

[1] Univ Sci & Technol China, State Key Lab Fire Sci, Hefei 230026, Anhui, Peoples R China

[2] Nagoya Univ, Inst Innovat Future Soc, Nagoya, Aichi 4648603, Japan

来源：

PROCEEDINGS OF THE COMBUSTION INSTITUTE | 2023年 / 39卷 / 03期

关键词：

Elevated-and ground pool fire; Cross airflow; Flame horizontal lengths; Air entrainment; Coanda effect; LARGE-EDDY SIMULATION; WIND; ATTACHMENT; BEHAVIOR; GEOMETRY;

D O I：

10.1016/j.proci.2022.09.038

中图分类号：

O414.1 [热力学];

学科分类号：

摘要：

The present study investigates experimentally the flame horizontal lengths of elevated pool fires and compares with those of ground pool fires in cross airflows. This, as a fundamental problem considering air entrainment and combustion structure change due to Coand a effect resulted from ground at leeward side, has not been quantified but is of practical significance. Experiments were performed employing both elevatedand ground square propane pool fires of various heat release rates in cross airflows from 0 & SIM;3.0 m/s with 224 test conditions in all. The overall flame horizontal length could be physically divided into two parts: part, L b ). Both the L m and the overall flame horizontal length showed to be significantly larger for a ground pool fire than those of an elevated one, due to the ground constraint effect on air entrainment at leeward side (Coand a effect). L b /( u 2 /g ) or L m /( u 2 /g ) of elevated fires is proportional to that of ground fires. Large eddy simulations for two representative fire scenarios were further conducted utilizing an in-house version of FireFOAM. The purpose of the simulations was to uncover the underlying physics of combustion and flow structures observed in the experiment. Finally, a model was proposed based on analysis of air entrainment, momentum- and buoyancy effects, which described well the overall flame horizontal lengths of both elevatedand ground pool fires generally as a function of non-dimensional heat release rate, normalized volumetric air entrainment and Froude numbers using L m and L b as length scales. This work provides new observation and basic quantification on elevated- and ground pool fire flame horizontal lengths considering air entrainment & COPY; 2022 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

引用

页码：4063 / 4073

页数：11

共 24 条

[11] JOHNSON AD, 1992, INST CHEM E, V130, P507
[12] Efficiencies of low-momentum jet diffusion flames in crosswinds
Johnson, MR
Kostiuk, LW
[J]. COMBUSTION AND FLAME, 2000, 123 (1-2) : 189 - 200
[13] Wind-blown pool fire, Part II: Comparison of measured flame geometry with semi-empirical correlations
Lam, Cecilia S.
Weckman, Elizabeth J.
[J]. FIRE SAFETY JOURNAL, 2015, 78 : 130 - 141
[14] Experimental study and physical analysis of flame geometry in pool fires under relatively strong cross flows
Lin, Yujie
Delichatsios, Michael A.
Zhang, Xiaolei
Hu, Longhua
[J]. COMBUSTION AND FLAME, 2019, 205 : 422 - 433
[15] Advances in modelling in CFD simulations of turbulent gaseous pool fires
Maragkos, Georgios
Beji, Tarek
Merci, Bart
[J]. COMBUSTION AND FLAME, 2017, 181 : 22 - 38
[16] McGrattan K.B., 2000, NISTIR6546
[17] McGrattan K.B., 2015, FIRE DYNAMICS SIMULA, V6th, P1018
[18] A Physical Model and Improved Experimental Data Correlation for Wind Induced Flame Drag in Pool Fires
Raj, Phani K.
[J]. FIRE TECHNOLOGY, 2010, 46 (03) : 579 - 609
[19] Effects of crosswind and burner aspect ratio on flame characteristics and flame base drag length of diffusion flames
Tang, Fei
He, Qing
Wen, Jennifer
[J]. COMBUSTION AND FLAME, 2019, 200 : 265 - 275
[20] Local flame attachment and heat fluxes in wind-driven line fires
Tang, Wei
Miller, Colin H.
Gollner, Michael J.
[J]. PROCEEDINGS OF THE COMBUSTION INSTITUTE, 2017, 36 (02) : 3253 - 3261

← 1 2 3 →