@article{chaudhury_ekkad_2026, title={Characteristics of Hydrogen-Piloted, Premixed Ammonia/Air Flames in a Swirl-Stabilized Gas Turbine Can Combustor: A Numerical Study}, volume={1}, url={http://dx.doi.org/10.2514/6.2026-0748}, DOI={10.2514/6.2026-0748}, abstractNote={Alternative fuel blends consisting of ammonia and hydrogen are now actively being considered in gas turbine combustors for power applications, as this is a potential way to achieve the net-zero goal in the coming decades. In this regard, the present research work focuses on numerically studying the combustion characteristics of hydrogen-piloted ammonia/air flames in a gas turbine can-combustor setup that is equipped with an industrial premix low-NOx swirl burner (SoLoNOx). Although the burner was originally designed and previously used for hydrocarbon-based fuel, in this research work the operational flexibility of the burner was investigated with zero-carbon fuels such as ammonia and hydrogen. A computational model of the combustor setup was created using SolidWorks and numerical study was performed under steady state conditions using the CONVERGE CFD 3.0 software. Using this software, turbulence and premixed combustion were modeled using the RANS RNG k-epsilon technique and the SAGE detailed chemical kinetic solver, respectively. Characteristics such as temperature, velocity and emissions were studied for different cases at equivalence ratio =0.6 and Reynolds number =50000; These cases were different with respect to their air inlet temperature and pilot fuel %. A suitable chemical mechanism from the literature consisting of 263 reactions and 38 species was used. The study found that SoLoNOx burner can be fuel-flexible under certain conditions. Preheating was found to be one of them which helped stabilize the hydrogen-piloted ammonia flame. This was possible because preheating was found to increase the extent and intensity of recirculation zones, thereby improving flame stabilization and combustion efficiency.}, journal={AIAA SCITECH 2026 Forum}, author={Chaudhury, Meghna Das and Ekkad, Srinath V.}, year={2026}, month={Jan} }
@article{phengsomphone_sahoo_chaudhury_ekkad_narayanaswamy_2026, title={Numerical Study of Premixed NH3 Flames in a Microscale Swirl Burner With an H2 Pilot Flame at Increased Pressures}, volume={1}, url={http://dx.doi.org/10.2514/6.2026-2180}, DOI={10.2514/6.2026-2180}, abstractNote={A microscale gas turbine combustor with a pilot flame design is developed and studied numerically to assess initial combustion performance of Ammonia (NH3) coupled with Hydrogen (H2) fuel. This numerical study uses CONVERGE computational fluid dynamics (CFD) software to model and simulate the reactant flow under increased pressure conditions of 1-5 atm on a structured mesh. All fuel and air are premixed, however the pilot torch is a H2 and air, and main flow is a NH3 and air mixture. Swirl blades are designed using a python script that generates airfoil shapes based on user inputs such as: 1) camber aggressiveness, location of camber apex, scaling factor, and pitch angle. All user inputs for this case then produces an effective swirl number that is not changed during this study. Simulation runs are thus parameterized by back pressure and air split ratio (ASP), and their respective flow fields are studied. The results show that the addition of H2 has raised the reactivity of the overall swirl flame, but additional combustion instability events have also been generated. NOx emissions measured at the combustor outlet are also seen to increase at increased pressures. The initial data given from these simulations will go into future design of a real life experimental microscale burner.}, journal={AIAA SCITECH 2026 Forum}, author={Phengsomphone, Adam and Sahoo, Abinash and Chaudhury, Meghna D. and Ekkad, Srinath V. and Narayanaswamy, Venkateswaran}, year={2026}, month={Jan} }
@article{das chaudhury_sahoo_ekkad_narayanaswamy_2025, title={Combustion Characteristics of Premixed Ammonia/Methane/Air Blends as an Alternative Fuel in a Swirl-Stabilized Gas Turbine Can Combustor Sustained Using a Pilot Flame}, volume={1}, ISSN={2997-0253 2997-0261}, url={http://dx.doi.org/10.1115/1.4067957}, DOI={10.1115/1.4067957}, abstractNote={Abstract The present research work investigated the combustion characteristics of lean premixed ammonia/methane/air flames in an atmospheric pressure swirl-stabilized gas turbine can combustor. The study focused on characteristics such as flame structure, flame stability, combustor liner wall heat load and emissions. Different volume % of ammonia–methane (0–50% ammonia, the rest being methane) blends were considered at an equivalence ratio = 0.6 and at Reynolds number ~50,000 where the flame was sustained using a 10% methane pilot flame. High-speed flame luminosity imaging was carried out to study characteristics such as flame structure and flame stability. Infrared thermography technique was used to simultaneously measure both outer and inner liner wall temperatures and to estimate the liner wall heat load. For studying emissions, steady-state numerical modeling was carried out using the converge cfd 3.0 software where both isothermal and adiabatic cases were studied; The latter comprised the entire volume fraction range of ammonia. Particle image velocimetry data were used to validate the numerical model. From the study, ammonia/methane/air flames were found to exhibit increased flame–turbulence interaction compared to the pure methane–air flame. Flame instability and flame extinction were observed in the 50% ammonia–50% methane flame in the downstream section of the combustor away from the pilot flame and along the combustor wall unlike the other flame cases. Compared to the combustor wall heat load in the pure methane–air flame, in ammonia/methane/air flames, the combustor wall heat load was found to be reduced by ~10% to 40% for various cases. In addition, NOx emissions for ammonia/methane/air flames were found to be less under isothermal wall conditions as compared to adiabatic wall condition because of unburnt fuel.}, number={4}, journal={Journal of Energy Resources Technology, Part A: Sustainable and Renewable Energy}, publisher={ASME International}, author={Das Chaudhury, Meghna and Sahoo, Abinash and Ekkad, Srinath V. and Narayanaswamy, Venkateswaran}, year={2025}, month={Mar} }
@article{chaudhury_sahoo_ekkad_narayanaswamy_2024, title={AN INVESTIGATION OF PILOT-ASSISTED PREMIXED AMMONIA/METHANE/AIR BLENDS AS ALTERNATIVE FUELS IN A SWIRL-STABILIZED GAS TURBINE COMBUSTOR}, volume={25}, ISSN={2150-3621}, url={http://dx.doi.org/10.1615/InterJEnerCleanEnv.2024051476}, DOI={10.1615/InterJEnerCleanEnv.2024051476}, abstractNote={In this work, the gas turbine combustor liner wall temperatures, wall heat load, and flame stability characteristics of swirl-stabilized, premixed ammonia (NH3)/methane (CH4)/air flames were investigated in an atmospheric pressure can combustor rig equipped with an industrial swirl burner. The volume percentages of NH3 and CH4 gases in the main fuel blend were varied from 10% to 60%, and a 10% C4 pilot flame was used to ignite and stabilize the main flame. In all cases, the Reynolds number and equivalence ratio were set to 50,000 and 0.65, respectively. The Infrared Thermography technique was used to measure the liner wall temperatures, and estimate the liner wall heat load. Additionally, the effect of increasing the NH3 volume percentage on the overall flame stability was qualitatively studied using a high-speed camera. The results showed that the liner wall heat load decreased as the NH3 volume percentage increased, with approximately 25% reduction observed in the 60% NH3 case compared to the 10% NH3 case. Stable flames were obtained up to 50% NH3, beyond which instabilities were observed in the form of oscillations with repetitive extinction and reignition occurring in the downstream portion of the flame. However, the pilot flame continued to sustain the upstream portion of the main flame, rendering the crown of each flame stable. Three-dimensional steady-state numerical simulations were carried out wherein the simulations revealed that unburnt fuel at the exhaust and outer recirculation zones increased as the NH3 volume percentage increased in the fuel blend.}, number={8}, journal={International Journal of Energy for a Clean Environment}, publisher={Begell House}, author={Chaudhury, Meghna Das and Sahoo, Abinash and Ekkad, Srinath V. and Narayanaswamy, Venkateswaran}, year={2024}, pages={15–39} }
@misc{das chaudhury_sahoo_nonavinakere vinod_fisher_ekkad_naranaswamy_fang_2024, title={Characteristics of Premixed Ammonia/Methane/Air Blends As an Alternative Fuel in a Swirl-Stabilized Gas Turbine Combustor Under Varying Pilot Percentage}, volume={2}, url={http://dx.doi.org/10.1115/GT2024-128437}, DOI={10.1115/GT2024-128437}, abstractNote={Abstract Alternative low carbon fuel blends are a promising way towards clean energy transition in the transportation and power generation sectors. In this work, the objective was to study the combustion characteristics of one such low carbon fuel blend (premixed Ammonia, Methane and Air) in a swirl stabilized Gas Turbine Can Combustor under varying % of pilot fuel flow (= 8 % to 10 % of the main fuel flow rate) at atmospheric pressure conditions. Pure Methane was used as the pilot flame which helped in the ignition and stabilization of the main flame and was kept on throughout the experiment. Different volume % of Ammonia and Methane blends were analyzed (starting from 10 to 50 % Ammonia in the fuel blend and the rest being Methane) at Reynolds number of the incoming air ∼ 50000, and at equivalence ratio = 0.6 and 0.7. Characteristics such as Combustor liner wall heat load and flame stability were studied using the Infrared Thermography technique and High-Speed flame imaging respectively. Additionally, both carbon and NOx emission trends were estimated for selected cases using the CONVERGE CFD software under steady state conditions incorporating the RANS RNG k-ϵ and SAGE modeling techniques. Among all cases, wall heat load was observed to be the least for the 50 % Ammonia-50 % Methane case and for cases under reduced pilot %. Also, under reduced pilot %, flames were mostly unstable wherein the manifestation of instabilities at equivalence ratio = 0.6 and 0.7 were markedly different from one another.}, journal={Volume 2: Ceramics and Ceramic Composites; Coal, Biomass, Hydrogen, and Alternative Fuels}, publisher={American Society of Mechanical Engineers}, author={Das Chaudhury, Meghna and Sahoo, Abinash and Nonavinakere Vinod, Kaushik and Fisher, Wesley and Ekkad, Srinath V. and Naranaswamy, Venkateswaran and Fang, Tiegang}, year={2024}, month={Jun} }
@article{chaudhury_sahoo_vinod_fisher_ekkad_narayanaswamy_fang_2024, title={Characteristics of Premixed Ammonia/Methane/Air Blends as an Alternative Fuel in a Swirl-Stabilized Gas Turbine Combustor Under Varying Pilot Percentage}, volume={146}, ISSN={0742-4795 1528-8919}, url={http://dx.doi.org/10.1115/1.4065923}, DOI={10.1115/1.4065923}, abstractNote={Abstract Alternative low carbon fuel blends are a promising way toward clean energy transition in the transportation and power generation sectors. In this work, the objective was to study the combustion characteristics of one such low carbon fuel blend (premixed Ammonia, Methane, and Air) in a swirl stabilized gas turbine can combustor under varying percentage of pilot fuel flow (=8–10% of the main fuel flowrate) under atmospheric pressure conditions. Pure Methane was used as the pilot flame which helped in the ignition and stabilization of the main flame and was kept on throughout the experiment. Different volume percentage of Ammonia and Methane blends was analyzed (starting from 10% to 50% Ammonia in the main fuel blend and the rest being Methane) at Reynolds number of the incoming air ∼50,000, and at equivalence ratio = 0.6 and 0.7. Characteristics such as combustor liner wall heat load and flame stability were studied using the Infrared Thermography technique and High-Speed flame imaging, respectively. In addition, both carbon and NOx emission trends were estimated for selected cases using the convergecfd software under steady-state conditions incorporating the Reynolds-averaged Navier-Stokes (RANS) re-normalization group (RNG) k–ϵ and SAGE modeling techniques. Among all cases, wall heat load was observed to be the least for the 50% Ammonia-50% Methane case, and for cases under reduced pilot percentage. Also, under reduced pilot percentage, flames were mostly unstable wherein the manifestation of instabilities at equivalence ratio = 0.6 and 0.7 was markedly different from one another.}, number={11}, journal={Journal of Engineering for Gas Turbines and Power}, publisher={ASME International}, author={Chaudhury, Meghna Das and Sahoo, Abinash and Vinod, Kaushik Nonavinakere and Fisher, Wesley and Ekkad, Srinath V. and Narayanaswamy, Venkateswaran and Fang, Tiegang}, year={2024}, month={Aug} }
@misc{gantt_chaudhury_ekkad_2023, title={Characteristics of Premixed Ammonia/Hydrogen/Methane Blends as an Alternative Fuel in a Swirl Stabilized Gas Turbine Combustor with Sustained Pilot}, url={http://dx.doi.org/10.2514/6.2023-0494}, DOI={10.2514/6.2023-0494}, abstractNote={Ammonia (NH3) and hydrogen (H2) are both being researched as alternative fuel sources for turbine combustion engines. While hydrogen has a high burn velocity, which can improve the response of a combustion engine, it can be difficult to store it in large quantities. Alternatively, ammonia is much easier to store in large quantities but suffers from a low burn speed and low flammability. This research focuses on how NH3/H2/CH4 blends will burn in an air breathing turbine system at high Reynolds numbers. In the present work, a swirl stabilized gas turbine combustor along with a pilot injector (methane (CH4) only) was the computational domain that closely resembled the experimental rig where the Reynolds number based on the swirler diameter was set at 50000 and the swirl number was close to 0.8. The simulation work was done in Converge CFD 3.0 by employing the RNG k-ε technique for modeling turbulence and SAGE detailed chemical kinetic solver to model the premixed combustion phenomena with a mechanism file from the literature that has been demonstrated to work well with NH3/H2/CH4 blends. Two main cases were explored: Case 1: 80% NH3, 5% H2, and 15% CH4 (% by volume), and Case 2: 75% NH3, 5% H2, and 20% CH4. These cases were used at seven different equivalence ratio cases ranging from 0.6 to 1.2. The combustion characteristics of these blends were then compared to a baseline case containing 80% NH3 and 20% CH4 to ascertain the role played by the 5% H2 in the original fuel blend Case 1) on NOX emissions and to determine what happens when NH3 was reduced by 5% (Case 2). The system was adiabatic and the modeling was conducted at standard atmospheric pressure. Data taken from these simulations have shown that, for these initial conditions, a stable flame is possible in both lean and fuel-rich cases.}, journal={AIAA SCITECH 2023 Forum}, publisher={American Institute of Aeronautics and Astronautics}, author={Gantt, Andrew and Chaudhury, Meghna and Ekkad, Srinath}, year={2023}, month={Jan} }
@misc{das chaudhury_sahoo_ekkad_narayanaswamy_2023, title={Combustor Wall Heat Transfer and Emission Characteristics of Premixed Ammonia/Methane/Air Blends in a Swirl Stabilized Gas Turbine Combustor}, volume={10}, url={http://dx.doi.org/10.1115/IMECE2023-112466}, DOI={10.1115/IMECE2023-112466}, abstractNote={Abstract Energy demand and carbon emission levels are increasing globally at an alarming rate leading to growing interest worldwide towards renewable and clean energy resources. In this context, the present research work investigated the combustor wall heat transfer and emission characteristics of Ammonia/Methane blends as a low carbon, clean energy resource with application to gas turbine power generation. Different volume % of Ammonia/Methane (0–50 % Ammonia) blends were considered at an equivalence ratio = 0.6 and at Reynolds number ∼50000 with a 10% Methane pilot which was used to ignite and stabilize the main flame. A quartz, atmospheric pressure, swirl stabilized, can combustor (swirl number∼0.8) rig equipped with an industrial burner was used for the experimental work. The same set-up had been previously used for studying hydrocarbon based fuels and the aim here was to study the possibility of using a cleaner gas turbine fuel by keeping the essential system hardware the same. Infrared Thermography technique was employed for estimating the wall temperatures and heat flux along the optical combustor wall and, this wall temperature was then used in the simulation work using CONVERGE CFD software incorporating the RANS RNG k-ϵ and SAGE techniques for predicting NOX and carbon emission levels and for studying the overall flame. Additionally, a highspeed camera was also used to qualitatively study the flame characteristics and flame stability. Upon comparing the results with a pure Methane-Air case, reduction in heat flux ranging between 30 to 40 % was observed for various Ammonia/Methane cases. Differences in NOX emission values between adiabatic and non-adiabatic cases were also observed along with significant reduction in carbon emissions by a maximum of 62%.}, journal={Volume 10: Heat Transfer and Thermal Engineering}, publisher={American Society of Mechanical Engineers}, author={Das Chaudhury, Meghna and Sahoo, Abinash and Ekkad, Srinath V. and Narayanaswamy, Venkateswaran}, year={2023}, month={Oct} }
@inproceedings{chaudhury_sahoo_ekkad_narayanaswamy_2023, title={Investigating the nature of Pilot-Assisted Premixed Ammonia/Methane/Air blends as an Alternative Fuel in a Swirl Stabilized Gas Turbine Combustor: Flame Stability and Wall Heat Transfer Study}, booktitle={47th International Technical Conference on Clean Energy}, author={Chaudhury, Meghna Das and Sahoo, Abinash and Ekkad, Srinath V. and Narayanaswamy, Venkateswaran}, year={2023}, month={Jul} }
@misc{das chaudhury_ekkad_kumar_2023, title={Numerical Simulation of Premixed Ammonia/Methane/Air blends in a Swirl-Stabilized Gas Turbine Combustor}, url={http://dx.doi.org/10.2514/6.2023-0497}, DOI={10.2514/6.2023-0497}, abstractNote={View Video Presentation: https://doi.org/10.2514/6.2023-0497.vid Research in the area of zero-carbon energy resources is gaining rapid momentum with the aim to cut down carbon emissions completely within the next few decades. There are a number of zero-carbon energy resources and Ammonia seems to be a promising candidate among them that definitely needs more research and understanding for implementation to industrial operating scales. In this regard, the present work attempts to numerically study various volume % of Ammonia and Methane as a premixed blend with application to gas turbine power generation. The computational domain used in the numerical simulation closely mimicked the actual atmospheric pressure annular combustor rig present in the lab that houses an industrial swirler and has the provision for a pilot flame for flame stabilization. Two different cases were studied: one with no cooling air injection and the other with cooling air injected at the downstream section of the combustor at equivalence ratios from 0.65 to 1.1. The entire 3-D simulation was done using CONVERGE CFD software where the premixed flame was modeled using SAGE detailed chemical kinetics solver, and turbulence was modeled using the RANS RNG k-ε technique. The model was validated with a previously published work in the literature and a current experimental work. Flame stabilization, carbon and NOX emissions were qualitatively as well as quantitatively studied at Reynolds number=50000 under steady state and adiabatic conditions. Analysis using ANSYS Chemkin was performed to complement the numerical findings of CONVERGE. Results showed drastic reduction in NOX emissions by more than 50 % with cooling air injection, along with reduced NOX emission values at lean and rich equivalence ratio conditions for both with and without cooling air cases. A numerically stabilized flame and realistic temperature distribution was observed for all cases except for cases with greater than 90 % Ammonia and at equivalence ratio greater than 1.05}, journal={AIAA SCITECH 2023 Forum}, publisher={American Institute of Aeronautics and Astronautics}, author={Das Chaudhury, Meghna and Ekkad, Srinath V. and Kumar, Gaurav}, year={2023}, month={Jan} }
@inbook{chaudhury_raju_2020, place={Singapore}, series={Lecture Notes in Mechanical Engineering}, title={Numerical Simulation of Heat Transfer and Fluid Flow Characteristics of Triangular Corrugated Wavy Channel}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85079642810&partnerID=MN8TOARS}, DOI={10.1007/978-981-15-1201-8_29}, booktitle={Advances in Applied Mechanical Engineering}, publisher={Springer}, author={Chaudhury, Meghna Das and Raju}, editor={Voruganti, Hari Kumar and Kumar, K. Kiran and Krishna, P. Vamsi and Jin, XiaoliangEditors}, year={2020}, pages={251–260}, collection={Lecture Notes in Mechanical Engineering} }
@article{chaudhury_raju_subramanian_2019, title={Metallurgical changes of cryogenically treated Coated Carbide (KC-9225) and its performance during wet machining of Austenitic Stainless Steel – 310.}, volume={502}, ISSN={1757-899X}, url={http://dx.doi.org/10.1088/1757-899X/502/1/012192}, DOI={10.1088/1757-899X/502/1/012192}, abstractNote={Various methods are employed to produce premium line of cutting tool materials with enhanced mechanical properties and improved service life. Cryogenic Treatment is one of those methods which has been considered for its benefits as a suitable add-on process. In this experimental investigation, Coated Tungsten-Carbide (KC9225) was taken as the cutting tool material and it was subjected to Deep Cryogenic-Treatment to analyse the several changes that might have taken place in its behaviour before and after the treatment. The treatment was carried out by a Dip-Stick arrangement where the temperature was gradually brought down to 100 K at the rate of ± 2 K/min. Tempering was also performed using the Dilatometer and the temperature was raised (~2 K/min) to 473 K. The changes in its mechanical properties both qualitatively as well quantitatively were investigated. Machining performance of the tool was also studied by performing wet turning on Austenitic Stainless Steel-310 where cutting force values were found to reduce by 3 to 71% in different cases thus proving its superiority as compared to the untreated tool.}, number={1}, journal={IOP Conference Series: Materials Science and Engineering}, publisher={IOP Publishing}, author={Chaudhury, Meghna Das and Raju and Subramanian, Anbarasu}, year={2019}, month={Apr}, pages={012192} }
@inproceedings{chaudhury_ghosh_2019, title={Numerical Simulation of Chilldown Process in Cryogenic Transportation Lines’}, booktitle={25th National and 3rd International Heat and Mass Transfer Conference (IHMTC 2019)}, author={Chaudhury, Meghna Das and Ghosh, Suman}, year={2019}, month={Dec} }
@inproceedings{chaudhury_bose_2018, title={A CFD analysis to show enhancement of heat transfer by CNT nanofluid in heat exchanger tubes at fully developed turbulent region’}, booktitle={1st International Conference on Mechanical Engineering (INCOM 2018)}, author={Chaudhury, Meghna Das and Bose, Anirban}, year={2018} }
@inproceedings{chaudhury_giri_bose_2018, title={Aerodynamic Design of High-Speed Train by CFD analysis’, Spectrum}, booktitle={International Students’ Conference on ‘Emerging Trends in Science and Technology}, publisher={Salt Lake City}, author={Chaudhury, Meghna Das and Giri, Subham and Bose, Anirban}, year={2018} }
@inproceedings{chaudhury_subramanian_subramanian_2018, title={Metallurgical changes of cryogenically treated Coated Carbide (KC-9225) and its performance during wet machining of Austenitic Stainless Steel – 310’}, booktitle={5th National Conference on Refrigeration and Air-Conditioning}, author={Chaudhury, Meghna Das and Subramanian, Raju and Subramanian, Anbarasu}, year={2018} }