This study investigates the impact of the near-wall temperature gradient on hydrogen auto-ignition characteristics using one-dimensional (1D) fully resolved simulations. Ten cases are simulated, one featuring normal combustion and the other nine simulating auto-ignitive combustion with different initial pressures, equivalence ratios, and near-wall temperature gradients. The simulations show that the near-wall temperature gradient greatly affects the onset and intensity of the auto-ignition event. For cases with the initial conditions of 833.3 K and 15 bar, a small near-wall temperature gradient delays the timing of auto-ignition and places the auto-ignition kernel further away from the wall, facilitating deflagration-to-detonation transition of the auto-ignitive flame. This leads to a large increase in pressure oscillations within the domain and heat flux to the wall. When the initial conditions are changed to 900 K and 20 bar, the magnitude of the near-wall temperature gradient also affects the number of auto-ignition events, leading to a significant impact on the wall heat flux. The results suggest that an accurate modeling of the near-wall temperature gradient is necessary for the simulations of hydrogen end-gas auto-ignition. This requires special considerations in the near-wall region and a careful selection of the wall heat transfer model in Computational Fluid Dynamics (CFD) tools, such as Reynolds-Averaged Navier–Stokes (RANS) and Large-Eddy Simulation (LES).

1.
P.
Dai
,
Z.
Chen
,
X.
Gan
, and
M. A.
Liberman
, “
Autoignition and detonation development from a hot spot inside a closed chamber: Effects of end wall reflection
,”
Proc. Combust. Inst.
38
,
5905
5913
(
2021
).
2.
P.
Dai
and
Z.
Chen
, “
Supersonic reaction front propagation initiated by a hot spot in n-heptane/air mixture with multistage ignition
,”
Combust. Flame
162
,
4183
4193
(
2015
).
3.
H.
Yu
,
C.
Qi
, and
Z.
Chen
, “
Effects of flame propagation speed and chamber size on end-gas autoignition
,”
Proc. Combust. Inst.
36
,
3533
3541
(
2017
).
4.
C.
Qi
,
P.
Dai
,
H.
Yu
, and
Z.
Chen
, “
Different modes of reaction front propagation in n-heptane/air mixture with concentration non-uniformity
,”
Proc. Combust. Inst.
36
,
3633
3641
(
2017
).
5.
H.
Yu
and
Z.
Chen
, “
End-gas autoignition and detonation development in a closed chamber
,”
Combust. Flame
162
,
4102
4111
(
2015
).
6.
X.
Zhang
,
H.
Wei
,
L.
Zhou
,
X.
Cai
, and
R.
Deiterding
, “
Relationship of flame propagation and combustion mode transition of end-gas based on pressure wave in confined space
,”
Combust. Flame
214
,
371
386
(
2020
).
7.
J.
Pan
,
S.
Dong
,
T.
Li
,
Y.
He
,
H.
Wei
, and
J.
Jiang
, “
Numerical simulations on autoignition propagation modes under reciprocating engine-relevant conditions
,”
Combust. Sci. Technol.
193
,
2241
2258
(
2021
).
8.
J.
Pan
,
H.
Wei
,
G.
Shu
, and
R.
Chen
, “
Effect of pressure wave disturbance on auto-ignition mode transition and knocking intensity under enclosed conditions
,”
Combust. Flame
185
,
63
74
(
2017
).
9.
J.
Pan
,
G.
Shu
,
P.
Zhao
,
H.
Wei
, and
Z.
Chen
, “
Interactions of flame propagation, auto-ignition and pressure wave during knocking combustion
,”
Combust. Flame
164
,
319
328
(
2016
).
10.
M. B.
Luong
,
S.
Desai
,
F. E.
Hernández Pérez
,
R.
Sankaran
,
B.
Johansson
, and
H. G.
Im
, “
Effects of turbulence and temperature fluctuations on knock development in an ethanol/air mixture
,”
Flow, Turbul. Combust.
106
,
575
595
(
2020
).
11.
J.
Jayachandran
and
F. N.
Egolfopoulos
, “
Thermal and Ludwig-Soret diffusion effects on near-boundary ignition behavior of reacting mixtures
,”
Proc. Combust. Inst.
36
,
1505
1511
(
2017
).
12.
N.
Kawahara
,
S.
Hashimoto
, and
E.
Tomita
, “
Spark discharge ignition process in a spark-ignition engine using a time series of spectra measurements
,”
Proc. Combust. Inst.
36
,
3451
3458
(
2017
).
13.
J.
Jayachandran
and
F. N.
Egolfopoulos
, “
Effect of unsteady pressure rise on flame propagation and near-cold-wall ignition
,”
Proc. Combust. Inst.
37
,
1639
1646
(
2019
).
14.
D.
Brouzet
,
A.
Haghiri
,
M.
Talei
, and
M. J.
Brear
, “
Annihilation events topology and their generated sound in turbulent premixed flames
,”
Combust. Flame
204
,
268
277
(
2019
).
15.
D.
Brouzet
,
M.
Talei
,
M. J.
Brear
, and
B.
Cuenot
, “
The impact of chemical modelling on turbulent premixed flame acoustics
,”
J. Fluid Mech.
915
,
1
33
(
2021
).
16.
R.
Palulli
,
M.
Talei
, and
R. L.
Gordon
, “
Unsteady flame–wall interaction: Impact on CO emission and wall heat flux
,”
Combust. Flame
207
,
406
416
(
2019
).
17.
R.
Palulli
,
M.
Talei
, and
R. L.
Gordon
, “
Analysis of near-wall CO due to unsteady flame-cooling air interaction
,”
Flow Turbul. Combust.
107
,
343
365
(
2021
).
18.
J. Z.
Ho
,
M.
Talei
,
R. L.
Gordon
, and
M. J.
Brear
, “
Reduced chemistry for sound generation by planar annihilation in premixed methane/hydrogen flames
,”
Proc. Combust. Inst.,
38
,
6125
6133
(
2021
).
19.
B.
Jiang
,
R. L.
Gordon
, and
M.
Talei
, “
Head-on quenching of laminar premixed methane flames diluted with hot combustion products
,”
Proc. Combust. Inst
37
,
5095
5103
(
2019
).
20.
M.
Baum
,
NTMIX/CHEMKIN—Release 2 User’s Guide
(CERFACS,
1995
), pp.
1
123
.
21.
M. P.
Burke
,
M.
Chaos
,
Y.
Ju
,
F. L.
Dryer
, and
S. J.
Klippenstein
, “
Comprehensive H2/O2 kinetic model for high-pressure combustion
,”
Int. J. Chem. Kinet.
44
,
444
474
(
2012
).
22.
N.
Chakraborty
,
E.
Mastorakos
, and
R. S.
Cant
, “
Effects of turbulence on spark ignition in inhomogeneous mixtures: A direct numerical simulation (DNS) study
,”
Combust. Sci. Technol.
179
,
293
317
(
2007
).
23.
G.
Lacaze
,
E.
Richardson
, and
T.
Poinsot
, “
Large eddy simulation of spark ignition in a turbulent methane jet
,”
Combust. Flame
156
,
1993
2009
(
2009
).
24.
G.
Lacaze
,
B.
Cuenot
,
T.
Poinsot
, and
M.
Oschwald
, “
Large eddy simulation of laser ignition and compressible reacting flow in a rocket-like configuration
,”
Combust. Flame
156
,
1166
1180
(
2009
).
25.
V.
Erard
,
A.
Boukhalfa
,
D.
Puechberty
, and
M.
Trinité
, “
A statistical study on surface properties of freely-propagating premixed turbulent flames
,”
Combust. Sci. Technol.
113
,
313
327
(
1996
).
26.
C.
Vázquez-Espí
and
A.
Linán
, “
Thermal-diffusive ignition and flame initiation by a local energy source
,”
Combust. Theory Model.
6
,
297
315
(
2002
).
27.
D.
Bradley
and
F. K.
Lung
, “
Spark ignition and the early stages of turbulent flame propagation
,”
Combust. Flame
69
,
71
93
(
1987
).
28.
F.
Poursadegh
,
M.
Brear
,
B.
Hayward
, and
Y.
Yang
, “
Autoignition, knock, detonation and the octane rating of hydrogen
,”
Fuel
332
,
126201
(
2023
).
29.
E. J.
Lyford-Pike
and
J. B.
Heywood
, “
Thermal boundary layer thickness in the cylinder of a spark-ignition engine
,”
Int. J. Heat Mass Transfer
27
,
1873
1878
(
1984
).
30.
V. N.
Gamezo
,
T.
Ogawa
, and
E. S.
Oran
, “
Flame acceleration and DDT in channels with obstacles: Effect of obstacle spacing
,”
Combust. Flame
155
,
302
315
(
2008
).
31.
H.
Terashima
,
A.
Matsugi
, and
M.
Koshi
, “
Origin and reactivity of hot-spots in end-gas autoignition with effects of negative temperature coefficients: Relevance to pressure wave developments
,”
Combust. Flame
184
,
324
334
(
2017
).
32.
D.
Bradley
, “
Hot spots’ and gasoline engine knock
,”
J. Chem. Soc., Faraday Trans.
92
,
2959
2964
(
1996
).
33.
D.
Bradley
,
X.
Gu
, and
D.
Emerson
, “
Modes of reaction front propagation from hot spots in flammable gaseous premixtures
,” in
Proceedings of 4th International Seminar on Fire and Explosion Hazards
, 8–12 September 2004 (
FireSERT
,
University of Ulster
,
2004
), pp.
819
828
.
34.
Y.
Li
,
W.
Gao
,
Y.
Li
,
Z.
Fu
, and
J.
Zou
, “
Numerical investigation on combustion and knock formation mechanism of hydrogen direct injection engine
,”
Fuel
316
,
123302
(
2022
).
35.
N.
Kawahara
and
E.
Tomita
, “
Visualization of auto-ignition and pressure wave during knocking in a hydrogen spark-ignition engine
,”
Int. J. Hydrogen Energy
34
,
3156
3163
(
2009
).
36.
M.
Ihme
, “
Combustion and engine-core noise
,”
Annu. Rev. Fluid Mech.
49
,
277
310
(
2017
).
37.
S.
Candel
, “
Combustion dynamics and control: Progress and challenges
,”
Proc. Combust. Inst.
29
,
1
28
(
2002
).
38.
K.
Loubar
,
J.
Bellettre
, and
M.
Tazerout
, “
Unsteady heat transfer enhancement around an engine cylinder in order to detect knock
,”
J. Heat Transfer
127
,
278
286
(
2005
).
39.
M.
Enomoto
, “
Sidewall quenching of laminar premixed flames propagating along the single wall surface
,”
Proc. Combust. Inst.
29
,
781
787
(
2002
).
40.
J.-H.
Lu
,
D.
Ezekoye
,
A.
Iiyama
,
R.
Greif
, and
R.
Sawyer
, “
Effect of knock on time-resolved engine heat transfer
,”
SAE
Paper No. 890158 (
1989
).
41.
B.
Grandin
,
I.
Denbratt
,
J.
Bood
,
C.
Brackmann
, and
P. E.
Bengtsson
, “
The effect of knock on the heat transfer in an SI engine: Thermal boundary layer investigation using CARS temperature measurements and heat flux measurements
,”
SAE trans
.
109
,
2003
2016
(
2000
), https://www.jstor.org/stable/44634368.
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