SiTCom-B Gallery - Revision history

Ribert: /* Numerical simulations of supercritical CH4/O2 flame propagation in inhomogeneous mixtures following ignition */

2023-01-23T02:11:05Z

‎Numerical simulations of supercritical CH4/O2 flame propagation in inhomogeneous mixtures following ignition

Ribert at 02:10, 23 January 2023

2023-01-23T02:10:38Z

Ribert: /* Numerical simulation of laminar premixed hydrogen-air flame/shock interaction in semi-closed channel */

2023-01-23T02:04:09Z

‎Numerical simulation of laminar premixed hydrogen-air flame/shock interaction in semi-closed channel

Ribert at 02:01, 23 January 2023

2023-01-23T02:01:28Z

Ribert: /* Simulation of high-pressure methane-oxygen combustion with a new reduced chemical mechanism */

2023-01-23T01:54:43Z

‎Simulation of high-pressure methane-oxygen combustion with a new reduced chemical mechanism

Ribert at 01:53, 23 January 2023

2023-01-23T01:53:55Z

Ribert at 01:53, 23 January 2023

2023-01-23T01:53:32Z

Ribert at 01:52, 23 January 2023

2023-01-23T01:52:38Z

Ribert at 01:50, 23 January 2023

2023-01-23T01:50:58Z

Ribert at 01:48, 23 January 2023

2023-01-23T01:48:59Z

@@ Line 7: / Line 7: @@
 | [[File:FOM2.png|center|800px]]
 |-
-| Blob of methane into pure oxygen. Temporal evolution of heat release rate (HRR) superposed with vorticity (ω) and mixture fraction (Z) according to the case number (w/o HIT, 1 or random blobs, temperature for methane or oxygen). Isolines: Zst in blue, T = 2500 K in green. The radius of the initial hot spot is rhs = 3Lbox/120. The full domain of simulation is shown.
+| Blob(s) of methane into pure oxygen. Temporal evolution of heat release rate (HRR) superposed with vorticity (ω) and mixture fraction (Z) according to the case number (w/o HIT, 1 or random blobs, temperature for methane or oxygen). Isolines: Zst in blue, T = 2500 K in green. The radius of the initial hot spot is rhs = 3Lbox/120. The full domain of simulation is shown.
 |-
 |}

← Older revision		Revision as of 02:10, 23 January 2023
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		+	== Numerical simulations of supercritical CH4/O2 flame propagation in inhomogeneous mixtures following ignition ==
		+
		+	The propagation of flames in non-homogeneous medium is studied for the particular case of the combustion of methane with oxygen at high pressure, in supercritical regime. A reduced chemistry containing 17 species and 44 elementary reactions is used in two configurations: 1/ a pocket of methane in a steady environment of oxygen at 10 MPa, and 2/ a double transcritical injection in a splitter plate configuration at 5.4 MPa. High fidelity simulations are carried out with the real gas version of the SiTCom-B numerical code. The addition of a hot spot to the reactive mixtures resulted in the formation of triple flames propagating along the stoichiometric isoline whatever the configuration chosen: with or without turbulence, cryogenic temperatures, random distribution of methane or not. In the case of a high density ratio between the two fluids (CH4 and O2), the flame naturally chooses to move towards that of lower density. In the case of the combustion of one pocket of methane, the addition of a homogeneous isotropic turbulence promotes combustion by increasing the length of the flame as well as the lean premixed combustion mode compared to the rich or non-premixed combustion. A similar behavior is observed when the pocket of CH4 is replaced by a set of random pockets. In the case of the splitter plate, tribachial flames propagating along the stoichiometric line are observed again. Combustion develops in finger-like structures mostly with a non-premixed mode of combustion. However, the lean and rich premixed combustion remains and the flame spreads towards the injector. The tip of the flame then attempts to pull up the flow into a reduced space stuck between dense oxygen and a rapid flow of methane.
		+	{\| class="wikitable"
		+	\|+ Supercritical Combustion
		+	\|-
		+	\| [[File:FOM2.png\|center\|800px]]
		+	\|-
		+	\| Blob of methane into pure oxygen. Temporal evolution of heat release rate (HRR) superposed with vorticity (ω) and mixture fraction (Z) according to the case number (w/o HIT, 1 or random blobs, temperature for methane or oxygen). Isolines: Zst in blue, T = 2500 K in green. The radius of the initial hot spot is rhs = 3Lbox/120. The full domain of simulation is shown.
		+	\|-
		+	\|}
		+
		+	*F. Monnier, G. Ribert (2022) Numerical simulations of supercritical CH4/O2 flame propagation in inhomogeneous mixtures following ignition, Proc. Combust. Inst. (in press). [https://www.sciencedirect.com/science/article/abs/pii/S1540748922002437?via%3Dihub link]
		+
	== Numerical simulation of laminar premixed hydrogen-air flame/shock interaction in semi-closed channel ==		== Numerical simulation of laminar premixed hydrogen-air flame/shock interaction in semi-closed channel ==

@@ Line 7: / Line 7: @@
 | [[File:EmY.png|center|800px]]
 |-
-| Temporal flow evolution of an incident shock (Ms) interacting with an H2/air flame. Isothermal walls, complex transport properties, ∆xi = 31.25 μm.
+| Temporal flow evolution of an incident shock (Ms) coming from the left and interacting with an H2/air flame before reflecting on the right side wall. Isothermal walls (top, bottom and right side), complex transport properties, ∆xi = 31.25 μm.
 |-
 |}

@@ Line 1: / Line 1: @@
 == Simulation of high-pressure methane-oxygen combustion with a new reduced chemical mechanism ==
@@ Line 7: / Line 21: @@
 | [[File:FMO.png|center|800px]]
 |-
-| 3D simulations: scalar fields of heat release rate (HRR), temperature (T), velocity magnitude U, vorticity (ω) and species mass fraction for CH4 (YCH4) is given from t = 2 × 10−7 s (top) to t = 1.4 × 10−6 s (bottom), each ∆t = 2 × 10−7 s. P=56bar,Φ=1,T =300Kinthefreshmixture.
+| 3D simulations: scalar fields of heat release rate (HRR), temperature (T), velocity magnitude U, vorticity (ω) and species mass fraction for CH4 (YCH4) is given from t = 2 × 10−7 s (top) to t = 1.4 × 10−6 s (bottom), each ∆t = 2 × 10−7 s. P = 56 bar, Φ = 1, T = 300 K in the fresh mixture.
 |-
 |}

@@ Line 11: / Line 11: @@
 |}
-*F. Monnier, G. Ribert (2022) Simulation of high-pressure methane-oxygen combustion with a new reduced chemical mechanism, Combust. Flame (235): 111735.
+*F. Monnier, G. Ribert (2022) Simulation of high-pressure methane-oxygen combustion with a new reduced chemical mechanism, Combust. Flame (235): 111735. [https://www.sciencedirect.com/science/article/abs/pii/S0010218021004788?via%3Dihub link]
-[https://www.sciencedirect.com/science/article/pii/S1540748920304181?via%3Dihub link]
 == Experimental and numerical studies of the diluent influence (N2, Ar, He, Xe) on stable premixed methane flames in micro-combustion ==

@@ Line 1: / Line 1: @@
 == Simulation of high-pressure methane-oxygen combustion with a new reduced chemical mechanism ==
-The modeling and simulation of methane-oxygen combustion at high pressure requires a dedicated kinetic mechanism to obtain a precise description of the fuel decomposition. However, using the detailed mech- anisms literature in high-fidelity simulations, like direct numerical simulations, is not possible due to the high numerical cost. Accordingly, a reduced chemical mechanism is required, and the one proposed in this study contains 17 species and 44 reactions to encompass a very large range of pressure (P ∈ [1, 100] bar) and equivalence ratio (φ ∈ [0.2, 14]). The Optimized and Reduced Chemistry method, that is based on directed relation graph with error propagation, is applied to the RAMEC kinetic scheme, and validations are performed for a set of canonical test-cases: auto-ignition delay simulation, one-dimensional laminar premixed flame freely propagating and one-dimensional counterflow diffusion flame. A very good agree- ment is obtained by comparison with the RAMEC detailed mechanism. To further evaluate the ability of the reduced mechanism, a premixed flame expanding in a homogeneous isotropic turbulence at high pressure (P = 56 bar) is performed. The temporal evolution of the flame front is detailed from its ignition, revealing the flame behavior and its interaction with turbulence. The new reduced chemical mechanism performs well with a relative error of 4% for the maximum of temperature at each time step and even less if the difference observed in the auto-ignition times between the two mechanisms is considered. Finally, a substantial gain is found when using the reduced scheme on three-dimensional cases, the simulations being 8 times faster than those using the detailed scheme. A dedicated post-processing tool based on the contour tracing labeling method is developed to measure the flame length.{| class="wikitable"
+The modeling and simulation of methane-oxygen combustion at high pressure requires a dedicated kinetic mechanism to obtain a precise description of the fuel decomposition. However, using the detailed mech- anisms literature in high-fidelity simulations, like direct numerical simulations, is not possible due to the high numerical cost. Accordingly, a reduced chemical mechanism is required, and the one proposed in this study contains 17 species and 44 reactions to encompass a very large range of pressure (P ∈ [1, 100] bar) and equivalence ratio (φ ∈ [0.2, 14]). The Optimized and Reduced Chemistry method, that is based on directed relation graph with error propagation, is applied to the RAMEC kinetic scheme, and validations are performed for a set of canonical test-cases: auto-ignition delay simulation, one-dimensional laminar premixed flame freely propagating and one-dimensional counterflow diffusion flame. A very good agree- ment is obtained by comparison with the RAMEC detailed mechanism. To further evaluate the ability of the reduced mechanism, a premixed flame expanding in a homogeneous isotropic turbulence at high pressure (P = 56 bar) is performed. The temporal evolution of the flame front is detailed from its ignition, revealing the flame behavior and its interaction with turbulence. The new reduced chemical mechanism performs well with a relative error of 4% for the maximum of temperature at each time step and even less if the difference observed in the auto-ignition times between the two mechanisms is considered. Finally, a substantial gain is found when using the reduced scheme on three-dimensional cases, the simulations being 8 times faster than those using the detailed scheme. A dedicated post-processing tool based on the contour tracing labeling method is developed to measure the flame length.
 |+ Supercritical Combustion
 |-

@@ Line 4: / Line 4: @@
 |+ Micro-combustion
 |-
-| [[File:FMO.pdf|center|800px]]
+| [[File:FMO.png|center|800px]]
 |-
 | 3D simulations: scalar fields of heat release rate (HRR), temperature (T), velocity magnitude U, vorticity (ω) and species mass fraction for CH4 (YCH4) is given from t = 2 × 10−7 s (top) to t = 1.4 × 10−6 s (bottom), each ∆t = 2 × 10−7 s. P=56bar,Φ=1,T =300Kinthefreshmixture.

← Older revision		Revision as of 01:48, 23 January 2023
Line 1:		Line 1:
		+	== Simulation of high-pressure methane-oxygen combustion with a new reduced chemical mechanism ==
		+
		+	The modeling and simulation of methane-oxygen combustion at high pressure requires a dedicated kinetic mechanism to obtain a precise description of the fuel decomposition. However, using the detailed mech- anisms literature in high-fidelity simulations, like direct numerical simulations, is not possible due to the high numerical cost. Accordingly, a reduced chemical mechanism is required, and the one proposed in this study contains 17 species and 44 reactions to encompass a very large range of pressure (P ∈ [1, 100] bar) and equivalence ratio (φ ∈ [0.2, 14]). The Optimized and Reduced Chemistry method, that is based on directed relation graph with error propagation, is applied to the RAMEC kinetic scheme, and validations are performed for a set of canonical test-cases: auto-ignition delay simulation, one-dimensional laminar premixed flame freely propagating and one-dimensional counterflow diffusion flame. A very good agree- ment is obtained by comparison with the RAMEC detailed mechanism. To further evaluate the ability of the reduced mechanism, a premixed flame expanding in a homogeneous isotropic turbulence at high pressure (P = 56 bar) is performed. The temporal evolution of the flame front is detailed from its ignition, revealing the flame behavior and its interaction with turbulence. The new reduced chemical mechanism performs well with a relative error of 4% for the maximum of temperature at each time step and even less if the difference observed in the auto-ignition times between the two mechanisms is considered. Finally, a substantial gain is found when using the reduced scheme on three-dimensional cases, the simulations being 8 times faster than those using the detailed scheme. A dedicated post-processing tool based on the contour tracing labeling method is developed to measure the flame length.{\| class="wikitable"
		+	\|+ Micro-combustion
		+	\|-
		+	\| [[File:icare.png\|center\|800px]]
		+	\|-
		+	\| 3D simulations - scalar fields of heat release rate (HRR), temperature (T), velocity magnitude U, vorticity (ω) and species mass fraction for CH4 (YCH4) is given from t = 2 × 10−7 s (top) to t = 1.4 × 10−6 s (bottom), each ∆t = 2 × 10−7 s. P=56bar,Φ=1,T =300Kinthefreshmixture.
		+	\|-
		+	\|}
		+
		+	*F. Monnier, G. Ribert (2022) Simulation of high-pressure methane-oxygen combustion with a new reduced chemical mechanism, Combust. Flame (235): 111735.
		+	[https://www.sciencedirect.com/science/article/pii/S1540748920304181?via%3Dihub link]
		+
	== Experimental and numerical studies of the diluent influence (N2, Ar, He, Xe) on stable premixed methane flames in micro-combustion ==		== Experimental and numerical studies of the diluent influence (N2, Ar, He, Xe) on stable premixed methane flames in micro-combustion ==