Trosolwg
Rwy'n Gydymaith Ymchwil ym Mhrifysgol Caerdydd, wedi'i leoli yng Nghanolfan Ymchwil Tyrbinau Nwy (GTRC) y Brifysgol ym Mhort Talbot. Fy mhrif ddiddordeb ymchwil yw gwella dealltwriaeth o hanfodion hylosgi ac effeithlonrwydd cylch posibl tanwydd carbon isel.
Ar ôl cwblhau gradd (mewn Peirianneg Integredig) a gradd meistr (mewn Astudiaethau Ynni) ym Mhrifysgol Caerdydd ar ddechrau'r 1990au, dychwelais yn ddiweddarach i gwblhau dau gontract fel cynorthwyydd ymchwil. Mae'r contract cyntaf yn fy ngalluogi i ddatblygu fy nealltwriaeth o brosesu tanwydd solet (pyrolysis, nwyeiddio a llosgi) wrth gynhyrchu modiwl meistr ar y pynciau hyn, a ariennir trwy'r Gronfa Menter Gwybodaeth (KEF).
Ar gyfer yr ail gontract, roeddwn yn gweithio yn y GTRC, lle cefais fy nghyfarfod am ddatblygu cyrsiau DPP ar gyfer diwydiant (a ariennir gan y Sefydliad Ymchwil Carbon Isel). Yn ystod y cyfnod hwn y dechreuais ddiddordeb mewn hylosgi nwyol, yn enwedig tanwydd carbon isel amgen. Gan hyrwyddo'r diddordeb hwn, rhwng 2017 a 2021 cwblheais PhD o'r enw 'Ymchwilio i botensial amonia llif gwastraff diwydiannol fel tanwydd ar gyfer cynhyrchu pŵer tyrbinau nwy carbon isel'. Roedd fy PhD yn cynnwys modelu rhifiadol ac ymchwiliadau arbrofol.
Yna cymerais fy mhrofiad i'r ymgynghoriaeth E4Tech (sydd bellach yn rhan o ERM) lle gweithiais am gyfnod byr fel ymgynghorydd Morwrol Carbon Isel cyn penderfynu ar rôl fwy 'ymarferol' gyda Tata Steel R&D (Heavy End) ym Mhort Talbot. Yn Tata, cyfrannais at wella sefydlogrwydd prosesau a throsglwyddo i wneud dur carbon is.
Yn 2023, dychwelais i'r GTRC fel ymchwilydd ôl-ddoethurol i gefnogi menter arwyddocaol genedlaethol National Gas Transmission (NGT), i gynnwys hydrogen yn grid nwy y DU. Yn y rôl hon, rwyf wedi ymgymryd â sawl prosiect sy'n anelu at ddeall rhai o oblygiadau technegol ac ymarferol y newidiadau arfaethedig i gyfansoddiad nwy yn y grid cenedlaethol.
Cyhoeddiad
2026
- Davies, T. et al. 2026. Influence of emissions normalisation methods on H2–CH4 fuel comparisons in generic and NOx-Abated gas turbine combustion. International Journal of Hydrogen Energy 223 154402. (10.1016/j.ijhydene.2026.154402)
- Vivoli, R. et al. 2026. Surface roughness effects on the operability and performance of a hydrogen jet burner. Journal of Engineering for Gas Turbines and Power 148 (1) 011014. (10.1115/1.4069474)
2025
- Vivoli, R. et al. 2025. Surface roughness effects on the operability and performance of a hydrogen jet burner. Presented at: ASME Turbo Expo 2025: Turbomachinery Technical Conference and Exposition Memphis, Tennessee, USA 16-20 June 2025. Proceedings of the Turbomachinery Technical Conference and Exposition. Vol. 3A.Combustion, Fuels & Emissions American Society of Mechanical Engineers. (10.1115/gt2025-151389)
- Hewlett, S. et al. 2025. The effects of secondary air staging location, pressure and humidification on NOx emissions for a high ammonia blend in premixed swirl combustion. Presented at: ASME Turbo Expo 2025: Turbomachinery Technical Conference and Exposition Memphis, Tennessee, USA 16-20 June 2025. Proceedings of the Turbomachinery Technical Conference and Exposition. Vol. 2.Coal, Biomass, Hydrogen & Alternative Fuels American Society of Mechanical Engineers(10.1115/gt2025-151612)
2022
- Alrebei, O. F. et al., 2022. Quantifying CO2 emissions and energy production from power plants to run HVAC systems in ASHRAE-based buildings. Energies 15 (23) 8813. (10.3390/en15238813)
- Alrebei, O. F. et al., 2022. Numerical investigation of a first-stage stator turbine blade subjected to NH3–H2/air combustion flue gases. International Journal of Hydrogen Energy 47 (78), pp.33479-33497. (10.1016/j.ijhydene.2022.07.190)
- Amhamed, A. I. et al., 2022. Ammonia production plants - a review. Fuels 3 (3), pp.408-435. (10.3390/fuels3030026)
- Fawwaz Aalrebei, O. et al., 2022. Ammonia-hydrogen-air gas turbine cycle and control analyses. International Journal of Hydrogen Energy 47 (13), pp.8603-8620. (10.1016/j.ijhydene.2021.12.190)
2021
- Pugh, D. et al. 2021. Emissions performance of staged premixed and diffusion combustor concepts for an NH3/air flame with and without reactant humidification. Journal of Engineering for Gas Turbines and Power 143 (5) 051012. (10.1115/1.4049451)
- Pugh, D. et al. 2021. Emissions performance of staged premixed and diffusion combustor concepts for an NH3/air flame with and without reactant humidification. Presented at: ASME Turbo Expo 2020: Turbomachinery Technical Conference & Exposition Virtual 21-25 September 2020. ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. Vol. 4A.ASME. (10.1115/GT2020-14953)
- Hewlett, S. 2021. Investigating the potential of industrial waste stream ammonia as a fuel for low carbon, gas turbine power generation. PhD Thesis , Cardiff University.
- Pugh, D. et al. 2021. An investigation of ammonia primary flame combustor concepts for emissions reduction with OH*, NH2* and NH* chemiluminescence at elevated conditions. Proceedings of the Combustion Institute 38 (4), pp.6451-6459. (10.1016/j.proci.2020.06.310)
2020
- Hewlett, S. G. et al. 2020. Industrial wastewater as an enabler of green ammonia to power via gas turbine technology. Presented at: Turbomachinery Technical Conference & Exposition (TURBO EXPO 2020) Virtual 21-25 September 2020. Proceedings of ASME Turbo Expo 2020 Turbomachinery Technical Conference and Exposition. Vol. 3.Vol. GT2020. ASME(10.1115/GT2020-14581)
2019
- Hewlett, S. et al. 2019. Gas turbine co-firing of steelworks ammonia with coke oven gas or methane: A fundamental and cycle Analysis. Presented at: ASME Turbo Expo 2019 Phoenix, Arizona, USA 17-21 June 2019. ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition: Volume 3: Coal, Biomass, Hydrogen, and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration; Organic Rankine Cycle Power Systems. ASME. , pp.GT2019-91404. (10.1115/GT2019-91404)
Cynadleddau
- Vivoli, R. et al. 2025. Surface roughness effects on the operability and performance of a hydrogen jet burner. Presented at: ASME Turbo Expo 2025: Turbomachinery Technical Conference and Exposition Memphis, Tennessee, USA 16-20 June 2025. Proceedings of the Turbomachinery Technical Conference and Exposition. Vol. 3A.Combustion, Fuels & Emissions American Society of Mechanical Engineers. (10.1115/gt2025-151389)
- Hewlett, S. et al. 2025. The effects of secondary air staging location, pressure and humidification on NOx emissions for a high ammonia blend in premixed swirl combustion. Presented at: ASME Turbo Expo 2025: Turbomachinery Technical Conference and Exposition Memphis, Tennessee, USA 16-20 June 2025. Proceedings of the Turbomachinery Technical Conference and Exposition. Vol. 2.Coal, Biomass, Hydrogen & Alternative Fuels American Society of Mechanical Engineers(10.1115/gt2025-151612)
- Pugh, D. et al. 2021. Emissions performance of staged premixed and diffusion combustor concepts for an NH3/air flame with and without reactant humidification. Presented at: ASME Turbo Expo 2020: Turbomachinery Technical Conference & Exposition Virtual 21-25 September 2020. ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. Vol. 4A.ASME. (10.1115/GT2020-14953)
- Hewlett, S. G. et al. 2020. Industrial wastewater as an enabler of green ammonia to power via gas turbine technology. Presented at: Turbomachinery Technical Conference & Exposition (TURBO EXPO 2020) Virtual 21-25 September 2020. Proceedings of ASME Turbo Expo 2020 Turbomachinery Technical Conference and Exposition. Vol. 3.Vol. GT2020. ASME(10.1115/GT2020-14581)
- Hewlett, S. et al. 2019. Gas turbine co-firing of steelworks ammonia with coke oven gas or methane: A fundamental and cycle Analysis. Presented at: ASME Turbo Expo 2019 Phoenix, Arizona, USA 17-21 June 2019. ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition: Volume 3: Coal, Biomass, Hydrogen, and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration; Organic Rankine Cycle Power Systems. ASME. , pp.GT2019-91404. (10.1115/GT2019-91404)
Erthyglau
- Davies, T. et al. 2026. Influence of emissions normalisation methods on H2–CH4 fuel comparisons in generic and NOx-Abated gas turbine combustion. International Journal of Hydrogen Energy 223 154402. (10.1016/j.ijhydene.2026.154402)
- Vivoli, R. et al. 2026. Surface roughness effects on the operability and performance of a hydrogen jet burner. Journal of Engineering for Gas Turbines and Power 148 (1) 011014. (10.1115/1.4069474)
- Alrebei, O. F. et al., 2022. Quantifying CO2 emissions and energy production from power plants to run HVAC systems in ASHRAE-based buildings. Energies 15 (23) 8813. (10.3390/en15238813)
- Alrebei, O. F. et al., 2022. Numerical investigation of a first-stage stator turbine blade subjected to NH3–H2/air combustion flue gases. International Journal of Hydrogen Energy 47 (78), pp.33479-33497. (10.1016/j.ijhydene.2022.07.190)
- Amhamed, A. I. et al., 2022. Ammonia production plants - a review. Fuels 3 (3), pp.408-435. (10.3390/fuels3030026)
- Fawwaz Aalrebei, O. et al., 2022. Ammonia-hydrogen-air gas turbine cycle and control analyses. International Journal of Hydrogen Energy 47 (13), pp.8603-8620. (10.1016/j.ijhydene.2021.12.190)
- Pugh, D. et al. 2021. Emissions performance of staged premixed and diffusion combustor concepts for an NH3/air flame with and without reactant humidification. Journal of Engineering for Gas Turbines and Power 143 (5) 051012. (10.1115/1.4049451)
- Pugh, D. et al. 2021. An investigation of ammonia primary flame combustor concepts for emissions reduction with OH*, NH2* and NH* chemiluminescence at elevated conditions. Proceedings of the Combustion Institute 38 (4), pp.6451-6459. (10.1016/j.proci.2020.06.310)
Gosodiad
- Hewlett, S. 2021. Investigating the potential of industrial waste stream ammonia as a fuel for low carbon, gas turbine power generation. PhD Thesis , Cardiff University.
Ymchwil
Prosiectau
Fel ymchwilydd ôl-ddoethurol ym Mhrifysgol Caerdydd, rwyf wedi cyfrannu at y prosiectau canlynol:
2025-26 Trosglwyddo Nwy Cenedlaethol: Astudiaeth Amrywioldeb Cymysgedd
Trosglwyddo Nwy Cenedlaethol 2024-25: Cronfa Arloesi Strwythurol - Cywasgu HyNTS Cyfnod Beta
Trosglwyddo Nwy Cenedlaethol 2023-24: Cronfa Arloesi Strwythurol - Gwelliannau Electrolyser wedi'u Gyrru gan Adfer Gwres Gwastraff