Staff Profile
Dr Umair Ahmed
Senior Lecturer in Computational Fluid Dynamics and Thermofluids
- Email: umair.ahmed@ncl.ac.uk
- Telephone: 0191 208 3625
- Address: School of Engineering,
Room 4.029, 4th Floor,
Stephenson Building,
Newcastle University,
Newcastle upon Tyne,
NE1 7RU
Dr Umair Ahmed obtained his undergraduate degree in mechanical engineering with 1st class Hons and the best overall performance award from the University of Manchester in 2010, which was followed by a PhD in mechanical engineering with an emphasis on Computational Fluid Dynamics (CFD) and computational combustion at the University of Manchester in 2014. He joined Newcastle University as a Lecturer in 2019, prior to this he has worked as a Research Associate at Newcastle University (2017-2019) and as a Research Associate and Teaching Fellow at the University of Manchester (2013-2017).
Dr Ahmed's research interests include Computational Fluid Dynamics (CFD), with a focus on turbulence, heat transfer, computational combustion, multiphase flows and non-Newtonian fluid flows. As part of his research he has been involved in several projects which range from Large Eddy Simulations (LES) of full scale rotating marine turbines, modelling of non-Newtonian fluids in industrial scale mixers, Reynolds Averaged Navier-Stokes (RANS) simulation of premixed turbulent combustion to Direct Numerical Simulation (DNS) of turbulence and combustion in free shear and wall bounded flows. Furthermore, he has also been involved in developing mathematical models for turbulence and combustion under the RANS and LES frameworks.
Areas of expertise
- Computational Fluid Dynamics (CFD)
- Direct Numerical Simulation (DNS) of turbulence, scalar mixing, heat transfer and combustion
- Modelling and simulation of turbulence, scalar mixing, heat transfer and combustion under Large Eddy Simulation (LES) and Reynolds Averaged Navier Stokes (RANS) frameworks
- Heat transfer modelling
- Numerical modelling of Non-Newtonian fluid flows
Memberships
- Member of the Combustion Institute (British Section)
- Member of UK Turbulence Consortium
- Fellow of the Higher Education Academy (FHEA)
- Member of the International Association for Hydro-Environment Engineering and Research (IAHR)
- Member of the Engineering and Physical Sciences Research Council Peer Review College
Awards
- 23rd Harold Jan Schoemaker Award (2023) from the International Association for Hydro-Environment Engineering and Research (IAHR) for the most outstanding paper published in the Journal of Hydraulic Research between 2020 and 2022.
- Awarded prize for the best presentation and the use of audio/visual aids in the UK Consortium on Turbulent Reacting flows (UKCTRF) annual meeting (2018).
- Nominated and shortlisted for the award of “Best Postgraduate Teacher” by the students’ union at the University of Manchester (2013).
- Best Overall Performance Award for Undergraduate Degree in Mechanical Engineering at The University of Manchester (2010).
Roles and Responsibilities
- Stage-4 year tutor for MEng in Mechanical Engineering (2023-Present).
- PGR Selector for Fluid Dynamics and Thermal Systems Group (2023-Present).
- Academic IT lead for the Stephenson Operational Group (new Stephenson building) (2023).
- Represent Newcastle University on the N8 Centre of Excellence in Computationally Intensive Research (N8 CIR) Steering Group (2022-Present).
- Member of the School of Engineering Online Facilitation Group (OFG) to facilitate online teaching of engineering (2020-2021).
- Steering Group member for the High Performance Computing (HPC) facility (ROCKET) at Newcastle University (2019-Present).
- Member of the NSS action plan committee for Mechanical Engineering (2019-2020).
Research Areas
- Computational Fluid Dynamics (CFD).
- Direct Numerical Simulation (DNS) of turbulence, scalar mixing, heat transfer and combustion.
- Modelling and simulation of turbulence, scalar mixing, heat transfer and combustion under Large Eddy Simulation (LES) and Reynolds Averaged Navier Stokes (RANS) frameworks.
- Heat transfer modelling.
- Numerical modelling of Non-Newtonian fluid flows.
- Developing new algorithms and open source CFD software for high performance computing (HPC) platforms.
Current Research Projects
Flame-wall interaction within turbulent boundary layers: Performing high-fidelity Direct Numerical Simulations (DNS) for premixed flames interacting with inert walls under fully developed turbulent boundary layer conditions. The data is then used to develop modelling strategies for simulating flows of industrial relevance using the RANS and LES frameworks.
Response of hydrogen flames to thermoacoustic excitation: Direct Numerical Simulation (DNS) calculations carried out for the response of hydrogen flames under different strain rate and thermoacoustic excitation levels. The results from this research are important from the point of view of developing stable gas turbine engines, which use hydrogen as a fuel, for power generation and aerospace industries.
Algorithms for Adaptive Mesh Refinement (AMR): Developing high-order/high-resolution algorithms for unstructured AMR techniques which can be used for simulating reacting flows, multi-phase flows and high-speed flows including supersonic and hypersonic flows.
Grants and Fellowships
2024: EPSRC research grant EP/Y017951/1 : Investigation of the influence of extinction strain rates and heat release rate on the stability of swirl stabilised hydrogen premixed flames (PI)
2023: EPSRC ARCHER2 pioneer project: Computational investigation of hydrogen-air premixed swirl flames (PI)
2021: EPSRC Access to High-Performance Computing: Modelling and Simulation of multi-physics reacting jet flows (PI)
2020: EPSRC ARCHER2 pioneer project: Flame-wall interaction of high hydrogen content premixed flames within turbulent boundary layers (PI)
2020: EPSRC research grant EP/V003534/1: A combined experimental and numerical investigation of premixed flame-wall interaction in turbulent boundary layers (Co-I)
2018: Japanese Society for the Promotion of Science short term fellowship: Collaborative research at Kyoto University on flame-wall interaction of hydrogen combustion (PI)
2010: The University of Manchester: Overseas Research Studentship (ORS) award for PhD in Computational Fluid Dynamics and Computational Combustion.
Current Teaching:
- MEC8062: Turbulent Fluid Flow and Modelling (2023-Present)
- MEC8099: Mechanical Engineering Team Project (module leader) (2023-Present)
- MEC3032: Advanced Thermofluid Dynamics (module leader) (2022-Present)
- MEC3098: Mechanical Engineering Project (2019-Present)
- MEC8095: MSc Project (2019-Present)
Previous Teaching:
- MEC3028: Computational Heat & Fluid Flow (module leader) (2020-2023)
- MEC8043: Software in the Professional Engineering Context (2019-2020)
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Articles
- Ghai S, Ahmed U, Chakraborty N. Statistical Behaviour and Modelling of Variances of Reaction Progress Variable and Temperature During Flame-Wall Interaction of Premixed Flames Within Turbulent Boundary Layers. Flow, Turbulence and Combustion 2024, 112, 845-878.
- Ahmed U, Ghai S, Chakraborty N. Relations between Reynolds stresses and their dissipation rates during premixed flame-wall interaction within turbulent boundary layers. Physics of Fluids 2024, 36(4), 045120.
- Abo-Amsha K, Awad HSAM, Ahmed U, Chakraborty N, Swaminathan N. On the Definition of Reaction Progress Variable in Exhaust Gas Recirculation Type Turbulent MILD Combustion of Methane and n-Heptane. Flow, Turbulence and Combustion 2024, 112, 1191-1213.
- Ghai S, Ahmed U, Chakraborty N. Modelling of the flame surface density transport during flame-wall interaction of premixed flames within turbulent boundary layers. Combustion Science and Technology 2024, epub ahead of print.
- Brearley P, Ahmed U, Chakraborty N. Implications of using scalar forcing to sustain reactant mixture stratification in Direct Numerical Simulations of turbulent combustion. Computation 2024, 12(6), 114.
- Chakraborty N, Dopazo C, Dunn H, Ahmed U. Evolution of Flame Displacement Speed Within Flame Front in Different Regimes of Premixed Turbulent Combustion. Flow, Turbulence and Combustion 2024, 112, 793-809.
- Ozel-Erol G, Ahmed U, Chakraborty N. Evolution of Displacement Speed Statistics during Head-On Flame-Wall Interaction within Turbulent Boundary Layers. Combustion Science and Technology 2024, ePub ahead of Print.
- Ahmed U, Ghai S, Chakraborty N. Direct Numerical Simulation Analysis of the Closure of Turbulent Scalar Flux during Flame–Wall Interaction of Premixed Flames within Turbulent Boundary Layers. Energies 2024, 17(8), 1930.
- Ahmed U, Ghai SK, Chakraborty N. Assessment of Laws of the Wall During Flame–Wall Interaction of Premixed Flames Within Turbulent Boundary Layers. Flow, Turbulence and Combustion 2024, 112, 1161-1190.
- Awad HSAM, Abo-Amsha K, Ahmed U, Chakraborty N. An Assessment of the Validity of Damköhler’s Hypotheses for Different Choices of Reaction Progress Variable in Homogenous Mixture Moderate or Intense Low-Oxygen Dilution (MILD) Combustion. Flow, Turbulence and Combustion 2024, 112, 897-915.
- Liu L, Ahmed U, Chakraborty N. A Comprehensive Evaluation of Turbulence Models for Predicting Heat Transfer in Turbulent Channel Flow Across Various Prandtl Number Regimes. Fluids 2024, 9(2), 42.
- Ghai S, Ahmed U, Klein M, Chakraborty N. Turbulent kinetic energy evolution in turbulent boundary layers during head-on interaction of premixed flames with inert walls for different thermal boundary conditions. Proceedings of the Combustion Institute 2023, 39(2), 2169-2178.
- Varma A, Ahmed U, Chakraborty N. Turbulence effects on the statistical behaviour and modelling of flame surface density and the terms of its transport equation in turbulent premixed flames. Flow, Turbulence and Combustion 2023, 111, 531-565.
- Ahmed U, Chakraborty N, Klein M. Influence of flow configuration and thermal wall boundary conditions on turbulence during premixed flame-wall interaction within low Reynolds number boundary layers. Flow, Turbulence and Combustion 2023, 111, 825-866.
- Ahmed U, Malkeson SP, Pillai A, Chakraborty N, Kurose R. Flame self interaction during turbulent boundary layer flashback of hydrogen-rich premixed combustion. Physical Review Fluids 2023, 8, 023202.
- Brearley P, Ahmed U, Chakraborty N. Effects of Mixture Distribution on the Structure and Propagation of Turbulent Stratified Slot-Jet Flames. Flow, Turbulence and Combustion 2023, 111, 769-797.
- Ghai SK, Ahmed U, Chakraborty N. Effects of Fuel Lewis Number on Wall Heat Transfer During Oblique Flame-Wall Interaction of Premixed Flames Within Turbulent Boundary Layers. Flow, Turbulence and Combustion 2023, 111, 867-895.
- Varma A, Ahmed U, Chakraborty N. Effects of body force on the statistical behaviour and modelling of scalar variance in turbulent premixed flames. Proceedings of the Combustion Institute 2023, 39(2), 2319-2328.
- Awad HSAM, Abo-Amsha K, Ahmed U, Swaminathan N, Chakraborty N. A Priori Direct Numerical Simulation Assessment of MILD Combustion Modelling in the Context of Reynolds Averaged Navier–Stokes Simulations. Flow, Turbulence and Combustion 2023, 111, 799-823.
- Brearley P, Ahmed U, Chakraborty N. Scalar Forcing Methodology for Direct Numerical Simulations of Turbulent Stratified Mixture Combustion. Flow, Turbulence and Combustion 2022, 108, 1089–1114.
- Chakraborty N, Rasool R, Ahmed U, Klein M. Relations between statistics of three-dimensional flame curvature and its two-dimensional counterpart in turbulent premixed flames. Flow, Turbulence and Combustion 2022, 109, 791-812.
- Ghai SK, Ahmed U, Chakraborty N, Klein M. Entropy generation during head-on interaction of premixed flames with inert walls within turbulent boundary layers. Entropy 2022, 24(4), 463.
- Ghai S, Chakraborty N, Ahmed U, Klein M. Enstrophy evolution during head-on wall interaction of premixed flames within turbulent boundary layers. Physics of Fluids 2022, 34(7), 075124.
- Ghai S, Ahmed U, Klein M, Chakraborty N. Energy integral equation for premixed flame-wall interaction in turbulent boundary layers and its application to turbulent burning velocity and wall flux evaluations. International Journal of Heat and Mass Transfer 2022, 196, 123230.
- Varma AR, Ahmed U, Chakraborty N. Effects of buoyancy on turbulent scalar flux closure for turbulent premixed flames in the context of Reynolds Averaged Navier–Stokes simulations. Combustion Theory and Modelling 2022, 26(4), 686-711.
- Varma AR, Ahmed U, Chakraborty N. Effects of Body Forces on Turbulent Kinetic Energy Transport in Premixed Flames. Flow, Turbulence and Combustion 2022, 109, 143-173.
- Varma A, Ahmed U, Chakraborty N. Effects of body forces on the statistics of flame surface density and its evolution in statistically planar turbulent premixed flames. Flow, Turbulence and Combustion 2022, 108, 181-212.
- Chakraborty N, Herbert A, Ahmed U, Im HG, Klein M. Assessment of Extrapolation Relations of Displacement Speed for Detailed Chemistry Direct Numerical Simulation Database of Statistically Planar Turbulent Premixed Flames. Flow, Turbulence and Combustion 2022, 108, 489-507.
- Awad HS, Abo-Amsha K, Ahmed U, Klein M, Chakraborty N. Assessment of Damköhler’s hypotheses in the thin reaction zones regime using multi-step chemistry Direct Numerical Simulations of statistically planar turbulent premixed flames. Physics of Fluids 2022, 34(5), 055120.
- Kai R, Pillai AL, Ahmed U, Chakraborty N, Kurose R. Analysis of the evolution of the Surface Density Function during premixed V-shaped flame-wall interaction in a turbulent channel flow at Reτ = 395. Combustion Science and Technology 2022, epub ahead of print.
- Cant RS, Ahmed U, Fang J, Chakraborty N, Nivarti G, Moulinec C, Emerson DR. An unstructured Adaptive Mesh Refinement approach for Computational Fluid Dynamics of reacting flows. Journal of Computational Physics 2022, 468, 111480.
- Chakraborty N, Ahmed U, Klein M, Im HG. Alignment statistics of pressure Hessian with strain rate tensor and reactive scalar gradient in turbulent premixed flames. Physics of Fluids 2022, 34(6), 065120.
- Brearley P, Ahmed U, Chakraborty N. A priori Direct Numerical Simulation analysis of the closure of cross-scalar dissipation rate of reaction progress variable and mixture fraction in turbulent stratified flames. Flow, Turbulence and Combustion 2022, 109, 351–382.
- Young FW, Awad HSAM, Abo-Amsha K, Ahmed U, Chakraborty N. A comparison between statistical behaviours of scalar dissipation rate between homogeneous MILD combustion and premixed turbulent flames. Energies 2022, 15(23), 9188.
- Lai J, Ahmed U, Klein M, Chakraborty N. A comparison between head-on quenching of stoichiometric methane-air and hydrogen-air premixed flames using Direct Numerical Simulations. International Journal of Heat and Fluid Flow 2022, 93, 108896.
- Ahmed U, Apsley D, Stallard T, Stansby P, Afgan I. Turbulent length scales and budgets of Reynolds stress-transport for open-channel flows; Friction Reynolds numbers (Reτ ) = 150, 400 & 1020. Journal of Hydraulic Research 2021, 59(1), 36-50.
- Ahmed U, Chakraborty N, Klein M. Scalar gradient and strain rate statistics in oblique premixed flame-wall interaction within turbulent channel flows. Flow, Turbulence and Combustion 2021, 106, 701-732.
- Kasten C, Ahmed U, Klein M, Chakraborty N. Principal strain rate evolution within turbulent premixed flames for different combustion regimes. Physics of Fluids 2021, 33(1), 015111.
- Ahmed U, Herbert A, Chakraborty N, Klein M. On the validity of Damköhler’s second hypothesis in statistically planar turbulent premixed flames in the thin reaction zones regime. Proceedings of the Combustion Institute 2021, 38(2), 3039-3047.
- Ahmed U, Chakraborty N, Klein M. Influence of thermal wall boundary condition on scalar statistics during flame-wall interaction of premixed combustion in turbulent boundary layers. International Journal of Heat and Fluid Flow 2021, 92, 108881.
- Ozel-Erol G, Ahmed U, Chakraborty N. Flame self-interactions in globally stoichiometric spherically expanding flames propagating into fuel droplet-mists. Proceedings of the Combustion Institute 2021, 38(2), 3351-3359.
- Malkeson SP, Ahmed U, Pillai A, Chakraborty N, Kurose R. Flame self-interactions in an open turbulent jet spray flame. Physics of Fluids 2021, 33(3), 035114.
- Chakraborty N, Kasten C, Ahmed U, Klein M. Evolutions of strain rate and dissipation rate of kinetic energy in turbulent premixed flames. Physics of Fluids 2021, 33, 125132.
- Malkeson SP, Ahmed U, Pillai AL, Chakraborty N, Kurose R. Evolution of Surface Density Function in an open turbulent jet spray flame. Flow, Turbulence and Combustion 2021, 106, 207-229.
- Varma A, Ahmed U, Klein M, Chakraborty N. Effects of turbulent length scale on the bending effect of turbulent burning velocity in premixed turbulent combustion. Combustion and Flame 2021, 233, 111569.
- Konstantinou I, Ahmed U, Chakraborty N. Effects of Fuel Lewis Number on the Near-wall Dynamics for Statistically Planar Turbulent Premixed Flames Impinging on Inert Cold Walls. Combustion Science and Technology 2021, 193(2), 235-265.
- Varma AR, Ahmed U, Chakraborty N. Effects of body forces on vorticity and enstrophy evolutions in turbulent premixed flames. Physics of Fluids 2021, 33(3), 035102.
- Awad H, Abo-Amsha K, Ahmed U, Chakraborty N. Comparison of the reactive scalar gradient evolution between homogeneous MILD combustion and premixed turbulent flames. Energies 2021, 14(22), 7677.
- Keil FB, Amzehnhoff M, Ahmed U, Chakraborty N, Klein M. Comparison of flame propagation statistics extracted from DNS based on simple and detailed chemistry Part 1: Fundamental flame turbulence interaction. Energies 2021, 14(17), 5548.
- Keil FB, Amzehnhoff M, Ahmed U, Chakraborty N, Klein M. Comparison of flame propagation statistics based on DNS of simple and detailed chemistry. Part 2: Influence of choice of reaction progress variable. Energies 2021, 14(18), 5695.
- Ahmed U, Chakraborty N, Klein M. Assessment of Bray Moss Libby formulation for premixed flame-wall interaction within turbulent boundary layers: Influence of flow configuration. Combustion and Flame 2021, 233, 111575.
- Brearley P, Ahmed U, Chakraborty N. The relation between flame surface area and turbulent burning velocity in statistically planar turbulent stratified flames. Physics of Fluids 2020, 32(12), 125111.
- Ahmed U, Pillai AL, Chakraborty N, Kurose R. Surface density function evolution and the influence of strain rates during turbulent boundary layer flashback of hydrogen-rich premixed combustion. Physics of Fluids 2020, 32(5), 055112.
- Brearley P, Ahmed U, Chakraborty N, Klein M. Scaling of Second-Order Structure Functions in Turbulent Premixed Flames in the Flamelet Combustion Regime. Fluids 2020, 5(2), 89.
- Tan G, Ahmed U, Wang L, Chakraborty N. Quantification of the flame structure at multi-scale levels. Physics of Fluids 2020, 32(12), 125110.
- Malkeson SP, Ahmed U, Turquand d'Auzay C, Pillai AL, Chakraborty N, Kurose R. Displacement speed statistics in an open turbulent jet spray flame. Fuel 2020, 286(Part 1), 119242.
- Herbert A, Ahmed U, Chakraborty N, Klein M. Applicability of extrapolation relations for curvature and stretch rate dependences of displacement speed for statistically planar turbulent premixed flames. Combustion Theory and Modelling 2020, 24(6), 1021-1038.
- Ahmed U, Turquand d'Auzay C, Muto M, Chakraborty N, Kurose R. Statistics of reaction progress variable and mixture fraction gradients of a pulverised coal jet flame using Direct Numerical Simulation data. Proceedings of the Combustion Institute 2019, 37(3), 2821-2830.
- Turquand d'Auzay C, Ahmed U, Pillai A, Chakraborty N, Kurose R. Statistics of progress variable and mixture fraction gradients in an open turbulent jet spray flame. Fuel 2019, 247, 198-208.
- Brearley P, Ahmed U, Chakraborty N, Lipatnikov A. Statistical behaviours of conditioned two-point second-order structure functions in turbulent premixed flames in different combustion regimes. Physics of Fluids 2019, 31(11), 115109.
- Ahmed U, Pillai A, Chakraborty N, Kurose R. Statistical behaviour of turbulent kinetic energy transport in boundary layer flashback of hydrogen-rich premixed combustion. Physical Review Fluids 2019, 4, 103201.
- Ahmed U, Chakraborty N, Klein M. On the stress-strain alignment in premixed turbulent flames. Scientific Reports 2019, 9, 5092.
- Ahmed U, Chakraborty N, Klein M. Insights into the bending effect in premixed turbulent combustion using the Flame Surface Density transport. Combustion Science and Technology 2019, 191(5-6), 898-920.
- Ahmed U, Doan NAK, Lai J, Klein M, Chakraborty N, Swaminathan N. Multiscale analysis of head-on quenching premixed turbulent flames. Physics of Fluids 2018, 30(10), 105102.
- Ahmed U, Michael V, Hou R, Mothersdale T, Prosser R, Kowalski A, Martin P. An energy transport based evolving rheology in high-shear rotor–stator mixers. Chemical Engineering Research and Design 2018, 133, 398-406.
- Ahmed U, Prosser R. A Posteriori Assessment of Algebraic Scalar Dissipation Models for RANS Simulation of Premixed Turbulent Combustion. Flow, Turbulence and Combustion 2018, 100(1), 39-73.
- Ahmed U, Apsley D, Afgan I, Stallard T, Stansby P. Fluctuating loads on a tidal turbine due to velocity shear and turbulence: comparison of CFD with field data. Renewable Energy 2017, 112, 235-246.
- Ahmed U, Prosser R. Modelling flame turbulence interaction in RANS simulation of premixed turbulent combustion. Combustion Theory and Modelling 2016, 20(1), 34-57.
- Ahmed U, Prosser R, Revell A. Towards the development of an evolution equation for flame turbulence interaction in premixed turbulent combustion. Flow, Turbulence and Combustion 2014, 93(4), 637-663.
- Ahmed U, Prosser R, Revell A. An evolution equation for flame turbulence interaction in premixed turbulent combustion. ERCOFTAC Bulletin 2014, 96.
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Conference Proceedings (inc. Abstracts)
- Mohan V, Ahmed U, Chakraborty N. Proper Orthogonal Decomposition of wall shear stress during head-on flame-wall interaction. In: 2nd International Conference on Mechanical Engineering. 2024, Kolkata, India: Department of Mechanical Engineering, Jadavpur University.
- Ghai SK, Ahmed U, Chakraborty N. Statistical behaviour of scalar variance transport during flame-wall interaction in turbulent boundary layers. In: 12th Mediterranean Combustion Symposium. 2023, Luxor, Egypt: The Combustion Institute.
- Ahmed U, Ghai S, Liu L, Chakraborty N. Statistical behaviour and closure of turbulent scalar flux during turbulent premixed flame-wall interaction within turbulent boundary layers. In: 11th European Combustion Meeting (ECM 2023). 2023, Rouen, France: Combustion Institute.
- Mohan V, Ahmed U, Chakraborty N. Proper orthogonal decomposition of wall heat flux for head-on premixed flame wall-interaction across turbulent boundary layers. In: 14th International Conference on Computational Heat and Mass Transfer (ICCHMT 2023). 2023, Düsseldorf, Germany.
- Ahmed U, Chakraborty N, Klein M. Influence of the variation in laminar burning velocity to friction velocity ratio on turbulent premixed flame-wall interaction within turbulent boundary layers. In: 11th European Combustion Meeting (ECM 2023). 2023, Rouen, France: Combustion Institute.
- Abo-Amsha K, Ahmed U, Chakraborty N. Flow topologies during Flame-Wall Interaction of premixed combustion in turbulent boundary layer. In: 14th International ERCOFTAC Symposium on Engineering Turbulence Modelling and Measurements (ETMM14). 2023, Barcelona, Spain.
- Awad HSAM, Abo-Amsha K, Ahmed U, Chakraborty N. Flame self-interactions in MILD combustion of homogeneous and inhomogeneous mixtures. In: 12th Mediterranean Combustion Symposium. 2023, Luxor, Egypt: The Combustion Institute.
- Chakraborty N, Dopazo C, Dunn H, Ahmed U. Evolution of flame displacement speed within flame front in different regimes of turbulent premixed combustion. In: 12th Mediterranean Combustion Symposium. 2023, Luxor, Egypt: The Combustion Institute.
- Ozel-Erol G, Ahmed U, Chakraborty N. Evolution of displacement speed statistics during flame-wall interaction within turbulent boundary layers. In: 29th International Colloquium on Dynamics of Explosions and Reactive Systems. 2023, South Korea.
- Chakraborty N, Ghai S, Ahmed U. Effects of fuel Lewis number on turbulent flow statistics in oblique-wall quenching of premixed V-shaped flames within turbulent channel flows. In: 14th International ERCOFTAC Symposium on Engineering Turbulence Modelling and Measurements (ETMM14). 2023, Barcelona, Spain.
- Awad HSAM, Abo-Amsha K, Ahmed U, Chakraborty N. A Priori Direct Numerical Simulation assessment of MILD combustion modelling in the context of Large Eddy Simulation. In: 15th International Conference on Combustion Technologies for a Clean Environment (CleanAir 2023). 2023, Lisbon.
- Awad HSAM, Abo-Amsha K, Ahmed U, Chakraborty N. A Direct Numerical Simulation based comparison between Homogenous and Inhomogeneous mixture MILD Combustion Modelling in the context of Reynolds Averaged Navier-Stokes Simulations. In: 11th European Combustion Meeting (ECM 2023). 2023, Rouen, France: Combustion Institute.
- Awad HSAM, Abo-Amsha K, Ahmed U, Chakraborty N. A Direct Numerical Simulation based comparison between conventional and MILD combustion processes of turbulent stratified mixtures. In: 29th International Colloquium on Dynamics of Explosions and Reactive Systems. 2023, South Korea.
- Cant RS, Ahmed U, Fang J, Chakraborty N, Moulinec C, Emerson D. Validation of the HAMISH code: DNS of combustion with Adaptive Mesh Refinement. In: 18th International Conference on Numerical Combustion. 2022, San Diego, USA.
- Brearley P, Ahmed U, Chakraborty N. Turbulent stratified mixture combustion with numerically forced bimodal mixture inhomogeneity. In: 33rd Parallel Computational Fluid Dynamics conference. 2022, Alba, Italy.
- Ahmed U, Ghai S, Chakraborty N, Klein M. Scalar statistics in premixed flame-wall interaction within turbulent boundary layers under different flow configurations. In: 17th UK Heat Transfer Conference. 2022, University of Manchester; Online.
- Chakraborty N, Ahmed U, Ghai S. Premixed Flame-Wall Interaction and Heat Transfer Characteristics in Turbulent Boundary Layers: Insights based on Direct Numerical Simulations. In: 5th International Symposium on Convective Heat and Mass Transfer (CONV-22). 2022, Izmir, Turkey.
- Ghai S, Ahmed U, Chakraborty N. Performance of wall functions in premixed flame-wall interaction within turbulent boundary layers. In: 33rd Parallel Computational Fluid Dynamics conference (ParCFD 2022). 2022, Alba, Italy.
- Ahmed U, Chakraborty N, Klein M. Influence of flow configuration and thermal wall boundary conditions on turbulence during premixed flame-wall interaction within boundary layers. In: 18th International Conference on Numerical Combustion. 2022, San Diego, USA.
- Ahmed U, Chakraborty N, Klein M. Influence of wall boundary conditions on premixed flame-wall interaction in turbulent boundary layers. In: European Combustion Meeting. 2021, Naples, Italy.
- Umair A, Chakraborty N, Klein M. Effects of Turbulent Boundary Layer on the Near-Wall Flame Dynamics in the Case of Adiabatic Walls. In: Engineering, Turbulence, Modelling and Measurements (ETMM13). 2021, Rhodes, Greece.
- Varma A, Ahmed U, Chakraborty N. Effects of buoyancy on turbulent kinetic energy transport in turbulent premixed flames. In: Engineering, Turbulence, Modelling and Measurements (ETMM13). 2021, Rhodes, Greece: ERCOFTAC.
- Awad H, Aboo Amsha K, Ahmed U, Chakraborty N. Comparison of Surface Density Function (SDF) statistics between MILD and premixed turbulent combustion. In: European Combustion Meeting. 2021, Naples, Italy: ECM.
- Brearley P, Ahmed U, Chakraborty N. A-priori Direct Numerical Simulation evaluation of the cross-scalar dissipation rate of reaction progress variable and mixture fraction in turbulent stratified flames. In: European Combustion Meeting. 2021, Naples, Italy (Virtual): ECM.
- Lai J, Ahmed U, Klein M, Chakraborty N. A comparison between head-on quenching of turbulent methane-air and hydrogen-air flames using detailed chemistry Direct Numerical Simulations. In: Engineering, Turbulence, Modelling and Measurements (ETMM13). 2021, Rhodes, Greece: ERCOFTAC.
- Konstantinou I, Ahmed U, Chakraborty N, Klein M. Statistics of turbulence during head-on quenching of premixed turbulent combustion in boundary layers. In: International Workshop on Clean Combustion: Principles and Applications. 2019, Darmstadt.
- Ahmed U, Pillai A, Chakraborty N, Kurose R. Statistical behaviour of turbulent kinetic energy transport in boundary layer flashback of hydrogen-rich premixed flames. In: 11th Mediterranean Combustion Symposium. 2019, Tenerife, Spain: International Centre for Heat and Mass Transfer.
- Ahmed U, Chakraborty N, Klein M. Scalar gradient and strain rate statistics in oblique premixed flame-wall interaction with turbulent boundary layers. In: International Workshop on Clean Combustion: Principles and Applications. 2019, Darmstadt.
- Ahmed U, Klein M, Chakraborty N. Oblique flame-wall interaction in premixed turbulent combustion under isothermal and adiabatic wall boundary conditions. In: 27th International Colloquium on Dynamics of Explosions and Reactive Systems. 2019, Beijing, China: Institute for Dynamics of Explosions and Reactive Systems.
- Konstantinou I, Ahmed U, Klein M, Chakraborty N. Near-wall behaviour of turbulence in flame-wall interaction of premixed turbulent combustion in boundary layers. In: 9th European Combustion Meeting (ECM 2019). 2019, Lisboa, Portugal.
- Ahmed U, Pillai AL, Chakraborty N, Kurose R. Mean behaviour of flame displacement speed in boundary layer flashback of hydrogen-rich premixed turbulent combustion. In: 12th Asia-Pacific Conference on Combustion (ASPACC 2019). 2019, Fukuoka: Combustion Institute.
- Konstantinou I, Ahmed U, Chakraborty N. Influence of fuel Lewis number on flame-wall interaction for impinging turbulent premixed flames. In: 27th International Colloquium on Dynamics of Explosions and Reactive Systems. 2019, Beijing, China: Institute for Dynamics of Explosions and Reactive Systems.
- Ahmed U, Chakraborty N, Klein M. Stress-strain alignment in premixed turbulent combustion. In: 12th International ERCOFTAC Symposium on Engineering Turbulence Modelling and Measurement (ETMM12). 2018, Montpelier, France.
- Michael V, Bagkeris I, Ahmed U, Prosser R, Kowalski A. Large-eddy simulation of non-circular jet flow in a pilot-scale inline high-shear static mixer. In: 12th International ERCOFTAC Symposium on Engineering Turbulence Modelling and Measurement (ETMM12). 2018, Montpelier, France.
- Ahmed U, Lai J, Doan NAK, Klein M, Chakraborty N, Swaminathan N. Effects of detailed chemistry on multiscale analysis of head-on quenching in premixed turbulent combustion. In: 12th International ERCOFTAC Symposium on Engineering Turbulence Modelling and Measurement (ETMM12). 2018, Montpelier, France.
- Ahmed U, Nivarti G, Zimon M, Prosser R, Cant R. The role of pressure Hessian in premixed turbulent combustion. In: Sixteenth SIAM International Conference on Numerical Combustion. 2017, Orlando, FL, USA: SIAM.
- Ahmed U, Prosser R, Kowalski A. An energy transport based evolving rheology. In: 9th International Symposium on Mixing in Industrial Processes. 2017, Birmingham, UK.
- Ahmed U, Afgan I, Apsley D, Stallard T, Stansby P. Large Eddy Simulations to represent a full-scale tidal stream flow and turbine. In: Oxford Tidal Energy Workshop. 2015, Oxford, UK: Pacific Northwest National Laboratory (PNNL).
- Ahmed U, Afgan I, Apsley D, Stallard T, Stansby P. CFD Simulations of a full-scale tidal turbine: Comparison of LES and RANS with field data. In: 11th European Wave and Tidal Energy Conference. 2015, Nantes, France.
- Ahmed U, Prosser R, Revell A. A transport equation for flame turbulence interaction in premixed turbulent combustion. In: European Combustion Meeting. 2013, Lund, Sweden.
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Report
- Afgan I, Ahmed U, Apsley D, Stallard T, Stansby P. CFD Simulations of a Full-Scale Tidal Stream Turbine: Comparison Between Large-Eddy Simulations and Field Measurements. UK: Energy Technologies Institute, 2014. MD1.4.