Guillaume Vignat

All Publications

• Deep reinforcement learning for adaptive control of thermoacoustic instabilities in a lean-premixed methane/hydrogen/air combustor COMBUSTION AND FLAME Akoush, B., Vignat, G., Finley, R., Chung, W., Ihme, M. 2025; 282

  View details for DOI 10.1016/j.combustflame.2025.114406

  View details for Web of Science ID 001577027000001

• A self-consistent analysis of cluster morphology in supercritical carbon dioxide from Small Angle X-ray Scattering CHEMICAL PHYSICS LETTERS Muhunthan, P., Majumdar, A., Younes, K., Vignat, G., Li, H., Rajkovic, I., Weiss, T., Sokaras, D., Ihme, M. 2025; 876

  View details for DOI 10.1016/j.cplett.2025.142190

  View details for Web of Science ID 001513620200002

• Supercritical Ethanol-CO2 Mixtures Exhibit Microscopic Immiscibility: A Combined Study Using X-ray Scattering and Molecular Dynamics Simulations. The journal of physical chemistry letters Fan, J., Yoon, T., Vignat, G., Li, H., Younes, K., Majumdar, A., Muhunthan, P., Sokaras, D., Weiss, T., Rajkovic, I., Ihme, M. 2025: 7090-7099

  Abstract

  Supercritical mixtures of ethanol (EtOH) and carbon dioxide (CO2) are classified as type-I mixtures, with complete macroscopic miscibility. However, differences in molecular polarity and interactions suggest a distinct phase behavior at the microscopic level. Here, we combine small angle X-ray scattering experiments and molecular dynamics (MD) simulations to investigate the microscopic structure of EtOH-CO2 mixtures under supercritical conditions. The structure factor exhibits nonlinear composition-dependent behavior, revealing pronounced local density fluctuations. The complementary MD simulations, using optimized force field parameters, provide atomistic insight, showing that EtOH forms self-associated, hydrogen-bonded aggregates, while CO2 remains more uniformly distributed. Cluster analysis identifies a preferential EtOH-rich composition exceeding the bulk average, governed by a balance between energetic and entropic competition. These results demonstrate that, contrary to macroscopic expectations, the mixture exhibits significant microscopic heterogeneity and immiscibility, which may influence solubility, reactivity, transport properties, and thermodynamic response functions. These findings challenge the conventional views of type-I fluids and emphasize the necessity of revising mixture states and considering molecular polarity.

  View details for DOI 10.1021/acs.jpclett.5c01293

  View details for PubMedID 40604336

• Burn parameters affect PAH emissions at conditions relevant for prescribed fires ATMOSPHERIC POLLUTION RESEARCH Topperwien, K., Vignat, G., Feinberg, A. J., Daube, C., Alton, M. W., Fortner, E. C., Canagaratna, M. R., Kling, M. F., Johnson, M., Nadeau, K., Herndon, S., Jayne, J. T., Ihme, M. 2025; 16 (5)

  View details for DOI 10.1016/j.apr.2025.102438

  View details for Web of Science ID 001428691500001

• Analysis of weak secondary waves in a rotating detonation engine using large-eddy simulation and wavenumber-domain filtering COMBUSTION AND FLAME Vignat, G., Brouzet, D., Bonanni, M., Ihme, M. 2024; 263

  View details for DOI 10.1016/j.combustflame.2024.113387

  View details for Web of Science ID 001203659500001

• Integrated experimental and computational analysis of porous media combustion by combining gas-phase synchrotron μCT, IR-imaging, and pore-resolved simulations COMBUSTION AND FLAME Boigne, E., Zirwes, T., Parkinson, D. Y., Vignat, G., Muhunthan, P., Barnard, H. S., MacDowell, A. A., Ihme, M. 2024; 259

  View details for DOI 10.1016/j.combustflame.2023.113132

  View details for Web of Science ID 001106259400001

• Experiment and modeling of stochastic ignition and combustion of fuel droplets impacting a hot surface PROCEEDINGS OF THE COMBUSTION INSTITUTE Ly, N., Ma, Y., Vignat, G., Hashimoto, N., Ihme, M. 2024; 40 (1-4)

  View details for DOI 10.1016/j.proci.2024.105747

  View details for Web of Science ID 001313236000001

• Experimental demonstration of a two-stage porous media burner for low-emission ammonia combustion PROCEEDINGS OF THE COMBUSTION INSTITUTE Vignat, G., Zirwes, T., Boigne, E., Ihme, M. 2024; 40 (1-4)

  View details for DOI 10.1016/j.proci.2024.105491

  View details for Web of Science ID 001297652000001

• Coupling of detonation structure and upstream inhomogeneities in a rotating detonation engine PROCEEDINGS OF THE COMBUSTION INSTITUTE Bonanni, M., Brouzet, D., Vignat, G., Ihme, M. 2024; 40 (1-4)

  View details for DOI 10.1016/j.proci.2024.105576

  View details for Web of Science ID 001278362400001

• A versatile pressure-cell design for studying ultrafast molecular-dynamics in supercritical fluids using coherent multi-pulse x-ray scattering. The Review of scientific instruments Muhunthan, P., Li, H., Vignat, G., Toro, E. R., Younes, K., Sun, Y., Sokaras, D., Weiss, T., Rajkovic, I., Osaka, T., Inoue, I., Song, S., Sato, T., Zhu, D., Fulton, J. L., Ihme, M. 2024; 95 (1)

  Abstract

  Supercritical fluids (SCFs) can be found in a variety of environmental and industrial processes. They exhibit an anomalous thermodynamic behavior, which originates from their fluctuating heterogeneous micro-structure. Characterizing the dynamics of these fluids at high temperature and high pressure with nanometer spatial and picosecond temporal resolution has been very challenging. The advent of hard x-ray free electron lasers has enabled the development of novel multi-pulse ultrafast x-ray scattering techniques, such as x-ray photon correlation spectroscopy (XPCS) and x-ray pump x-ray probe (XPXP). These techniques offer new opportunities for resolving the ultrafast microscopic behavior in SCFs at unprecedented spatiotemporal resolution, unraveling the dynamics of their micro-structure. However, harnessing these capabilities requires a bespoke high-pressure and high-temperature sample system that is optimized to maximize signal intensity and address instrument-specific challenges, such as drift in beamline components, x-ray scattering background, and multi-x-ray-beam overlap. We present a pressure cell compatible with a wide range of SCFs with built-in optical access for XPCS and XPXP and discuss critical aspects of the pressure cell design, with a particular focus on the design optimization for XPCS.

  View details for DOI 10.1063/5.0158497

  View details for PubMedID 38170817

• Improving volume-averaged simulations of matrix-stabilized combustion through direct X-ray μCT characterization: Application to NH₃/H₂-air combustion COMBUSTION AND FLAME Zirwes, T., Vignat, G., Toro, E. R., Boigne, E., Younes, K., Trimis, D., Ihme, M. 2023; 257

  View details for DOI 10.1016/j.combustflame.2023.113020

  View details for Web of Science ID 001077127800001

• Swirling spray flames dynamical blow out induced by transverse acoustic oscillations PROCEEDINGS OF THE COMBUSTION INSTITUTE Patat, C., Baillot, F., Blaisot, J., Domingues, E., Vignat, G., Soundararajan, P., Renaud, A., Durox, D., Candel, S. 2023; 39 (4): 4651-4659

  View details for DOI 10.1016/j.proci.2022.08.029

  View details for Web of Science ID 001021009300001

• Combustion of lean ammonia-hydrogen fuel blends in a porous media burner PROCEEDINGS OF THE COMBUSTION INSTITUTE Vignat, G., Akoush, B., Toro, E. R., Boigne, E., Ihme, M. 2023; 39 (4): 4195-4204

  View details for DOI 10.1016/j.proci.2022.07.054

  View details for Web of Science ID 001018624900001

• Experimental and numerical investigation of flame stabilization and pollutant formation in matrix stabilized ammonia-hydrogen combustion COMBUSTION AND FLAME Vignat, G., Zirwes, T., Toro, E. R., Younes, K., Boigne, E., Muhunthan, P., Simitz, L., Trimis, D., Ihme, M. 2023; 250

  View details for DOI 10.1016/j.combustflame.2023.112642

  View details for Web of Science ID 000945070400001

• Dynamics and structure of detonations in stratified product-gas diluted mixtures PROCEEDINGS OF THE COMBUSTION INSTITUTE Brouzet, D., Vignat, G., Ihme, M. 2023; 39 (3): 2855-2864

  View details for DOI 10.1016/j.proci.2022.07.173

  View details for Web of Science ID 001017579200001

• Comparison of Flame Describing Functions Measured in Single and Multiple Injector Configurations JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME Soundararajan, P., Durox, D., Vignat, G., Renaud, A., Beaunier, J., Candel, S. 2022; 144 (11)

  View details for DOI 10.1115/1.4055451

  View details for Web of Science ID 000883168700009

• Do flame describing functions suitably represent combustion dynamics under self-sustained oscillations? JOURNAL OF SOUND AND VIBRATION Soundararajan, P., Vignat, G., Durox, D., Renaud, A., Candel, S. 2022; 534

  View details for DOI 10.1016/j.jsv.2022.117034

  View details for Web of Science ID 000813339100002

• p Swirler effects on combustion instabilities analyzed with measured FDFs, injector impedances and damping rates COMBUSTION AND FLAME Soundararajan, P., Durox, D., Renaud, A., Vignat, G., Candel, S. 2022; 238

  View details for DOI 10.1016/j.combustflame.2021.111947

  View details for Web of Science ID 000745063300001

• The suitability of different swirl number definitions for describing swirl flows: Accurate, common and (over-) simplified formulations PROGRESS IN ENERGY AND COMBUSTION SCIENCE Vignat, G., Durox, D., Candel, S. 2022; 89

  View details for DOI 10.1016/j.pecs.2021.100969

  View details for Web of Science ID 000739484300001

• A Joint Experimental and Large Eddy Simulation Characterization of the Liquid Fuel Spray in a Swirl Injector JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME Vignat, G., Rajendram Soundararajan, P., Durox, D., Vie, A., Renaud, A., Candel, S. 2021; 143 (8)

  View details for DOI 10.1115/1.4049771

  View details for Web of Science ID 000680416800023

• Improvement of lean blow out performance of spray and premixed swirled flames using nanosecond repetitively pulsed discharges PROCEEDINGS OF THE COMBUSTION INSTITUTE Vignat, G., Minesi, N., Soundararajan, P., Durox, D., Renaud, A., Blanchard, V., Laux, C. O., Candel, S. 2021; 38 (4): 6559-6566

  View details for DOI 10.1016/j.proci.2020.06.136

  View details for Web of Science ID 000640405500011

• Investigation of transient PVC dynamics in a strongly swirled spray flame using high speed planar laser imaging of SnO2 microparticles COMBUSTION AND FLAME Vignat, G., Durox, D., Renaud, A., Lancien, T., Vicquelin, R., Candel, S. 2021; 225: 305-319

  View details for DOI 10.1016/j.combustflame.2020.11.009

  View details for Web of Science ID 000614036500002

• Effect of Different Fuels on Combustion Instabilities in an Annular Combustor JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME Soundararajan, P., Vignat, G., Durox, D., Renaud, A., Candel, S. 2021; 143 (3)

  View details for DOI 10.1115/1.4049702

  View details for Web of Science ID 000626499800017

• Large-Eddy Simulation of Flame Dynamics During the Ignition of a Swirling Injector Unit and Comparison With Experiments JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME Topperwien, K., Collin-Bastiani, F., Riber, E., Cuenot, B., Vignat, G., Prieur, K., Durox, D., Candel, S., Vicquelin, R. 2021; 143 (2)

  View details for DOI 10.1115/1.4049297

  View details for Web of Science ID 000617335900002

• Combustion Dynamics of Annular Systems COMBUSTION SCIENCE AND TECHNOLOGY Vignat, G., Durox, D., Schuller, T., Candel, S. 2020; 192 (7): 1358-1388

  View details for DOI 10.1080/00102202.2020.1734583

  View details for Web of Science ID 000519517100001

• Dynamics of spray and swirling flame under acoustic oscillations : A joint experimental and LES investigation PROCEEDINGS OF THE COMBUSTION INSTITUTE Vignat, G., Lo Schiavo, E., Laera, D., Renaud, A., Gicquel, L., Durox, D., Candel, S. 2020; 38 (4): 6015-6024

  View details for DOI 10.1016/j.proci.2020.05.054

  View details for Web of Science ID 000640387700020

• High Amplitude Combustion Instabilities in an Annular Combustor Inducing Pressure Field Deformation and Flame Blow Off JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME Vignat, G., Durox, D., Renaud, A., Candel, S. 2020; 142 (1)

  View details for DOI 10.1115/1.4045515

  View details for Web of Science ID 000525413900016

• Flame and Spray Dynamics During the Light-Round Process in an Annular System Equipped With Multiple Swirl Spray Injectors JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME Prieur, K., Vignat, G., Durox, D., Schuller, T., Candel, S. 2019; 141 (6)

  View details for DOI 10.1115/1.4042024

  View details for Web of Science ID 000468915800008

• HIGH AMPLITUDE COMBUSTION INSTABILITIES IN AN ANNULAR COMBUSTOR INDUCING PRESSURE FIELD DEFORMATION AND FLAME BLOW-OFF Vignat, G., Durox, D., Renaud, A., Candel, S., ASME AMER SOC MECHANICAL ENGINEERS. 2019

  View details for Web of Science ID 000502163800044

• An experimental study into the effect of injector pressure loss on self-sustained combustion instabilities in a swirled spray burner PROCEEDINGS OF THE COMBUSTION INSTITUTE Vignat, G., Durox, D., Prieur, K., Candel, S. 2019; 37 (4): 5205-5213

  View details for DOI 10.1016/j.proci.2018.06.125

  View details for Web of Science ID 000457095600100

• FLAME AND SPRAY DYNAMICS DURING THE LIGHT-ROUND PROCESS IN AN ANNULAR SYSTEM EQUIPPED WITH MULTIPLE SWIRL SPRAY INJECTORS Prieur, K., Durox, D., Vignat, G., Schuller, T., Candel, S., ASME AMER SOC MECHANICAL ENGINEERS. 2018

  View details for Web of Science ID 000456494200037

• ANALYSIS OF PERFORMANCE SENSITIVITY TO GEOMETRICAL VARIATIONS OF A MODERN HELICOPTER ENGINE COMBUSTOR USING LES SIMULATIONS Vignat, G., Taliercio, G., Lamouroux, J., Da Veiga, S., Savary, N., Duchaine, P., ASME AMER SOC MECHANICAL ENGINEERS. 2017

  View details for Web of Science ID 000412782400003