麻豆传媒

Andy joined 麻豆传媒 in January 2017 as a Lecturer of Thermofluid Dynamics.  He obtained an MMath from the University of Oxford in 2002, followed by a PhD in Applied Mathematics from the University of Cambridge in 2006. He was awarded a Glenn T Seaborg Fellowship at the Lawrence Berkeley National Laboratory, where he was a member of the Center for Computational Sciences and Engineering for five years. Before joining 麻豆传媒, he was a Lecturer of Applied Mathematics at the University of Southampton, a Lecturer of Computational Fluid Dynamics at Cranfield University, and before that a Lecturer of Engineering Sciences at the University of Portsmouth.

Andy's research involves mathematical analysis and high-fidelity three-dimensional numerical simulation to study the fundamentals of turbulence and combustion (especially thermodiffusively-unstable lean premixed hydrogen flames) to enable the development and validation of engineering models that can be used to design efficient low-emission combustor technology for transport and power generation.

Areas of expertise
   - Thermofluid dynamics
   - Turbulent combustion
   - Thermodiffusively-unstable lean premixed hydrogen flames
   - Entrainment in turbulent jets
   - Computational Fluid Dynamics (CFD)
   - Direct Numerical Simulation (DNS) with detailed chemistry
   - Implicit Large Eddy Simulation (ILES)

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Andy's research involves the analysis and simulation of turbulent fluid mechanics with and without combustion, mainly through massively-parallel direct numerical simulation (DNS). Applications include turbulent premixed flames, in particular thermodiffusively-unstable lean premixed hydrogen flames, and premixed flames at extreme turbulence levels (the distributed burning regime); entrainment in turbulent jets; numerical methods for turbulent fluid dynamics - implicit large eddy simulation; and type Ia supernovae.

Turbulent Combustion using Direct Numerical Simulation with Detailed Chemistry

Andy's turbulent combustion research uses the of solvers (developed at the and as part of the ). The aim is to conduct DNS with detailed chemistry to understand the fundamentals of turbulent flames and bridge the gap between first-principle simulations and turbulent-flame modelling approaches for engineering applications, thereby enabling the development of next generation zero-carbon combustors.

  - Howarth, Picciani, Richardson, Day & Aspden, 265 (2024)

  - Kim, Kim, Aspden & Shin, 253 (2023)

  - Lyu, Aspden, Zhang, Liu & Qiu, 46 (2021)

  - Dasgupta, Sun, Day, Aspden & Lieuwen, 207 (2019)

  - Aspden, Zettervall & Fureby,  37 (2019)

  - Aspden, Bell, Day & Egolfopoulos,  36 (2017)

  - Aspden, Day & Bell, 166 (2016)

  - Chatakonda, Hawkes, Aspden, Kerstein, Kolla & Chen, 160 (2013)

Thermodiffusively-unstable Lean Premixed Hydrogen Flames

Hydrogen is carbon-free and so naturally produces zero CO2 when burned, which makes it an attractive alternative to conventional fuels for power generation, heating and propulsion. Hydrogen is a special fuel; it has a high energy density, it is highly diffusive, and burns hotter and faster than typical hydrocarbons. A potential approach to control the high temperatures and speeds is to burn in a lean premixed mode (like a blue Bunsen flame). However, lean premixed hydrogen can be thermodiffusively unstable, due to the high diffusivity of the fuel. This is a significant challenge to predicting flame behaviour, and turbulent-flame modelling in particular.

  - Hunt & Aspden, 272 (2025)

  - Aspden, Howarth & Hunt, 40 (2024)

  - Howarth, Day, Pitsch & Aspden, 40 (2024)

  - Howarth, Hunt & Aspden, 253 (2023)

  - Howarth & Aspden, 237 (2022)

  - Aspden, 36 (2017)

  - Aspden, Day & Bell, 35 (2015)

  - Aspden, Day & Bell, 33 (2011a)

Premixed Flames at Extreme Turbulence: the Distributed Burning Regime

Flames propagation results from a balance between thermal and species diffusion with chemical reactions. When turbulent premixed flames are exposed to sufficiently high levels of turbulence, mixing by molecular diffusion becomes dominated by turbulent mixing, which results in a transition to distributed burning regime.

  - Aspden, Day & Bell,  871 (2019)

  - Aspden, Day & Bell,  33 (2011b)

  - Aspden, Day & Bell, 680 (2011)

Entrainment in Turbulent Jets

Turbulent jets and plumes occur in a variety of applications, from atmospheric convection and cloud formation, fuel injection in IC engines, and volcanoes.  

  - Shin, Aspden, Aparece-Scutariu & Richardson, (2023)

  - Shin, Aspden & Richardson, 833 (2017)

  - Aspden, Nikiforakis, Bell & Dalziel, 824 (2017)

  - Scase, Aspden & Caulfield, 635 (2009)

Numerical Methods for Turbulent Fluid Dynamics

Implicit Large Eddy Simulation (ILES) exploits properties of non-oscillatory finite-volume numerical schemes to simulate turbulent flows without explicitly modelling small-scale dissipation of kinetic energy.

  - Almgren, Aspden, Bell & Minion, 35 (2013)

  - Aspden, Nikiforakis, Dalziel & Bell, 3 (2008)

Type Ia Supernovae

Type Ia Supernovae (SNeIa) are used as "standard candles" to estimate astronomical distances. In SNeIa, carbon atoms fuse to become silicon releasing heat, resulting in a propagating flame similar to those in terrestrial premixed combustion. Improving understanding of the mechanism by which SNeIa explode can help with the interpretation of astronomical observations and understand the rate of expansion of the universe.

  - Nonaka, Aspden, Zingale, Almgren, Bell & Woosley, 745 (2012)

  - Aspden, Bell, Dong & Woosley,  738 (2011)

  - Aspden, Bell & Woosley,  734 (2011)

  - Aspden, Bell & Woosley,  710 (2010)

  - Woosley, Kerstein, Sankaran, Aspden & Röpke,  704 (2009)

  - Aspden, Bell, Day, Woosley & Zingale,  689 (2008)

• Articles

  • Hunt EF, Moitro A, Aspden AJ. . Combustion and Flame 2026, 286, 114845.
  • Chaib O, Bae J, Weller L, Aspden AJ, Hochgreb S. . Combustion and Flame 2026, 286, 114852.
  • Moitro A, Hunt EF, Howarth TL, Chaib O, Bae J, Weller L, Hochgreb S, Aspden AJ. . Combustion and Flame 2026, 288, 114916.
  • Russell GS, Howarth TL, Skiba AW, Carter CD, Aspden AJ. . Proceedings of the Combustion Institute 2025, 41, 105868.
  • Bae J, Chaib O, Weller L, Moitro A, Hunt EF, Aspden AJ, Hochgreb S. . Proceedings of the Combustion Institute 2025, 41, 105919.
  • Aspden AJ, Howarth TL, Hunt EF. . Proceedings of the Combustion Institute 2024, 40(1-4), 105634.
  • Hunt EF, Aspden AJ. . Combustion and Flame 2024, 272, 113855.
  • Howarth TL, Day MS, Pitsch H, Aspden AJ. . Proceedings of the Combustion Institute 2024, 40(1-4), 105429.
  • Howarth TL, Picciani MA, Richardson ES, Day MS, Aspden AJ. . Combustion and Flame 2024, 265, 113504.
  • Shin D, Aspden AJ, Aparece-Scutariu V, Richardson ES. . Physics of Fluids 2023, 35, 015139.
  • Howarth TL, Hunt EF, Aspden AJ. . Combustion and Flame 2023, 253, 112811.
  • Kim K, Kim YJ, Aspden AJ, Shin D-H. . Combustion and Flame 2023, 253, 112815.
  • Lyu Y, Aspden AJ, Zhang L, Liu L, Qiu P. . International Journal of Hydrogen Energy 2021, 46(24), 13402-13412.
  • Howarth TL, Aspden AJ. . Combustion and Flame 2021, 237, 111805.
  • Aspden AJ, Day MS, Bell JB. . Journal of Fluid Mechanics 2019, 871, 1-21.
  • Dasgupta D, Sun W, Day MS, Aspden AJ, Lieuwen T. . Combustion and Flame 2019, 207, 36-50.
  • Aspden AJ, Zettervall N, Fureby C. . Proceedings of the Combustion Institute 2019, 37(2), 2301-2609.
  • Aspden AJ, Nikiforakis N, Bell JB, Dalziel SB. . Journal of Fluid Mechanics 2017, 824, 766-784.
  • Aspden AJ, Bell JB, Day MS, Egolfopoulos FN. . Proceedings of the Combustion Institute 2017, 36(2), 2005-2016.
  • Shin D-H, Aspden AJ, Richardson E. . Journal of Fluid Mechanics 2017, 833.
  • Aspden AJ. . Proceedings of the Combustion Institute 2017, 36(2), 1997-2004.
  • Aspden AJ, Day MS, Bell JB. . Combustion and Flame 2016, 166, 266-283.
  • Aspden AJ, Day MS, Bell JB. . Proceedings of the Combustion Institute 2015, 35(2), 1321-1329.
  • Schmidt W, Almgren AS, Braun H, Engels JF, Niemeyer JC, Schultz J, Mekuria RR, Aspden AJ, Bell JB. . Monthly Notices of the Royal Astronomical Society 2014, 440(4), 3051-3077.
  • Kuhl AL, Bell AJ, Beckner VE, Balakrishnan K, Aspden AJ. Spherical combustion clouds in explosions. Shock Waves 2013, 23(3), 233–249.
  • Almgren AS, Aspden AJ, Bell JB, Minion M. On the Use of Higher-Order Projection Methods for Incompressible Turbulent Flow. SIAM Journal on Scientific Computing 2013, 35(1), B25-B42.
  • Chatakonda O, Hawkes ER, Aspden AJ, Kerstein AR, Kolla H, Chen JH. . Combustion and Flame 2013, 160(11), 2422-2433.
  • Nonaka AJ, Aspden AJ, Zingale M, Almgren AS, Bell JB, Woosley SE. High-Resolution Simulations of Convection Preceding Ignition in Type Ia Supernovae Using Adaptive Mesh Refinement. Astrophysical Journal 2012, 745, 73-94.
  • Aspden AJ, Bell JB, Woosley SB. Turbulent Oxygen Flames in Type Ia Supernovae. Astrophysical Journal 2011, 730, 144-151.
  • Aspden AJ, Day MS, Bell JB. Turbulence-Flame Interactions in Lean Premixed Hydrogen: transition to the distributed burning regime. Journal of Fluid Mechanics 2011, 680, 287-320.
  • Aspden AJ, Day MS, Bell JB. Lewis Number Effects in Distributed Flames. Proceedings of the Combustion Institute 2011, 33(1), 1473-1480.
  • Woosley SE, Kerstein AR, Aspden AJ. Flames in Type Ia Supernova: Deflagration-Detonation Transition in the Oxygen Burning Flame. Astrophysical Journal 2011, 734, 37-41.
  • Aspden AJ, Day MS, Bell JB. Characterization of Low Lewis Number Flames. Proceedings of the Combustion Institute 2011, 33, 1463-1471.
  • Aspden AJ, Bell JB, Dong S, Woosley SE. Burning Thermals in Type Ia Supernovae. Astrophysical Journal 2011, 738, 94-107.
  • Aspden AJ, Bell JB, Woosley SE. Distributed Flames in Type Ia Supernovae. Astrophysical Journal 2010, 710(2).
  • Woosley SE, Kerstein AR, Sankaran V, Aspden AJ, Röpke F. Type Ia Supernovae: Calculations of Turbulent Flames Using the Linear Eddy Model. Astrophysical Journal 2009, 704, 255-273.
  • Scase MM, Aspden AJ, Caulfield CP. The effect of sudden source buoyancy flux increases on turbulent plumes". Journal of Fluid Mechanics 2009, 635, 137-169.
  • Aspden AJ, Nikiforakis N, Dalziel SB, Bell JB. Analysis of Implicit LES Methods. Communications in Applied Mathematics and Computational Science 2009, 3, 103-126.
  • Aspden AJ, Bell JB, Day MS, Woosley SE, Zingale M. Turbulence-Flame Interactions in Type Ia Supernovae. Astrophysical Journal 2008, 689(2), 1173-1185.
  • Davidson PA, Sreenivasan B, Aspden AJ. Evolution of localised blobs of swirling or buoyant fluid with and without an ambient magnetic field. Physical Review E 2007, 75.