About

Jason M. Merret is a Professor of Practice in the Department of Aerospace Engineering at the University of Illinois Urbana-Champaign. He holds a Ph.D. in Aerospace Engineering from the same university, with a dissertation focused on Reentry Vehicle Aerodynamics and Control at Very High Angle of Attack. His academic background also includes a Master's and Bachelor's degree in Aeronautical and Astronautical Engineering from the University of Illinois, graduating with University Honors and Highest Honors in the College of Engineering. His research interests encompass aircraft design, applied aerodynamics, flight mechanics, and experimental aerodynamics. Merret has contributed to various conference proceedings and has been actively involved in research related to liquid hydrogen propulsion systems for electrified aircraft, drag reduction techniques for eVTOL configurations, and the impact of fuel cell-electric propulsion on aircraft configuration and integration. He has also worked on developing training programs for airworthiness engineering and configuration-independent initial sizing methods for urban air mobility and eVTOL vehicles. Professionally, Merret has served as a Clinical Associate Professor at the University of Illinois since July 2018 and has taught aerospace-oriented classes for Gulfstream and Embry Riddle Aeronautical University. His professional society involvement includes roles within the American Institute of Aeronautics and Astronautics, where he is an Associate Fellow and has held leadership positions in various technical committees. He has received several honors, including the Stanley H. Pierce Faculty Award in 2023 and recognition as an Outstanding Recent Alumnus in 2014. Merret is also recognized for his dedication to student mentorship and has received multiple awards for his teaching, notably in the AIAA Student Aircraft Design Competition.

Research topics

• Automotive engineering
• Engineering
• Aerospace engineering
• Computer Science
• Electrical engineering
• Chemistry
• Environmental science

Selected publications

• WITHDRAWN: Integration of Natural Language Processing and Large Language Models for Automated SysML Generation with Topological Robustness Benchmarking in MBSE

  2026-01-08

  articleSenior author

  The current generation of aerospace systems is getting much more complex and that pace continues to accelerate. This demands Model Based Systems Engineering (MBSE) workflows that turn text based documents into traceable SysML components while preserving design structure and minimizing manual effort. This work generated an AI automated framework that converts text based system descriptions into Papyrus compatible SysML components, eliminating a time consuming portion of early phase modeling tasks. This paper presents two extraction pipelines: (1) a rule-based NLP path built on spaCy and (2) a Large Language Model (LLM) path that uses prompt engineered queries to GPT-4o. Both pipelines output Papyrus standard .uml, .di, and .notation files. A gold standard manual model was introduced and verified by the authors to be reliable for current standard set from reputed sources. Then these pipelines were tested on a GPT-4o generated synthetic reference set of SysML models which was curated from the gold standard upon which further analyses are conducted. The study outlines the system architecture, requirement decomposition, and evaluation protocols. It shows that the LLM pipeline delivers higher recall on complex relationship structures, while the NLP pipeline offers deterministic execution time and fine grained controllability over the reference models. Building on this foundational analysis, the study conducted additional experiments which include a 100 system synthetic aerospace corpus with reference SysML models, a chaos monkey perturbation engine that injects lexical/semantic/structural noise, and a Graph Edit Distance (GED) metric to capture topological fidelity beyond token level F1. Present SOTA LLMs were benchmarked under clean and noisy conditions and an agentic Reflexion loop was implemented for self correction. Topological fidelity remained stable under perturbation (NLP: mean GED 23.1 ± 7.8 clean vs 20.6 ± 7.3 noisy, p = 4.3 × 10−4; LLM: 16.0 ± 6.8 clean vs 15.7 ± 5.4 noisy, p = 0.51), while Reflexion improved 19% of samples but degraded 54% (mean ΔGED = +1.13, p = 0.007). In the nine model benchmark, Grok-4 (0709) achieved the lowest GED (28.2), and Gemini 3 Pro delivered the best cost intelligence trade off (GED 33.2 at $2); Claude Sonnet 4.5 was mid at $3. These results establish GED as a structural complement to F1. Overall, the framework reduces modeling effort from hours to minutes, a significant advantage in AI assisted MBSE.

  PublisherDOI

• WITHDRAWAL: Integration of Natural Language Processing and Large Language Models for Automated SysML Generation with Topological Robustness Benchmarking in MBSE

  2026-01-12

  articleSenior author
  PublisherDOI

• Trade-Space Assessment of Liquid Hydrogen Propulsion Systems for Electrified Aircraft

  Journal of Aircraft · 2025-02-10 · 2 citations

  article

  In this paper, we assess the feasibility of turbo-, hybrid-, and fully electric civil aircraft propulsion systems. A modular optimization framework was developed to quantify system performance for a single-aisle transport aircraft with a mission similar to a Boeing 737-800. Various propulsion systems leveraging superconducting motors, boundary-layer ingestion, distributed electric propulsion, proton exchange membrane fuel cells, and liquid hydrogen fuel were examined for the same notional aircraft. Conventional aviation turbine fuel and liquid hydrogen were compared using the payload-fuel energy intensity, the fuel energy required per product of range and payload. For the chosen mission, the energy intensity of the hydrogen-fueled fully electric configuration was similar to that of the conventionally fueled twin turbofan baseline but produced zero carbon dioxide or nitrogen oxide emissions during flight. Relative to this baseline, a hydrogen-fueled turbofan system had the lowest energy intensity. Energy intensity increased when adding fuel cells to a turboelectric system or batteries to a fully electric, fuel-cell-powered system.

  PublisherDOI

• Developing training programs for Airworthiness Engineering

  2024-02-08

  articleOpen accessSenior author

  Abstract Aircraft of all types provide resources to support humanitarian efforts through the world. Advanced UAS operations like Zipline blood/vaccine delivery in Ghana and Rwanda, transport of COVID vaccines on multiple types of aircraft, and new and novel search and rescue aircraft (public and military aircraft) are a few examples of aircraft employed for humanitarian missions. Engineers need strong airworthiness training to ensure safety of pilots, passengers, and people overflown. Engineers and professionals who understand the science of airworthiness are critical to safety, functionality, and certification of aircraft. Until recently, training in airworthiness engineering was done through company and agency training programs, mentorship, and tacit knowledge sharing. Aerospace engineering programs educated individuals on the fundamentals of aircraft design and manufacturing, but not the skillsets and requirements for the airworthiness certification of aircraft and safety of flight assurance. The number of professionals who have this needed experience and qualifications are limited and thus there developed a clear need create a baseline for formal educational programs in Airworthiness Engineering for undergraduate, graduate, and professional levels of attainment. The Aerospace Industries Association (AIA) in partnership with the Federal Aviation Administration (FAA), U.S. Department of Defense and Embry Riddle Aeronautical University took on a project to invigorate and expand the airworthiness talent pool, to define common curricula for Airworthiness Engineering programs and define professional levels based on experience and responsibility. This effort would ensure and improve airworthiness compliance and safety for civil and military aerospace systems and embed airworthiness discipline as part of the design and development life cycle of aircraft. The paper we will present will share the approach taken by an integrated group of industry, government, and academia to develop standards defining the minimum requirements for formal education for undergraduate, graduate, and professional levels.

  PublisherOA PDFDOI

• Impact of Liquid-Hydrogen Fuel-Cell Electric Propulsion on Aircraft Configuration and Integration

  Journal of Aircraft · 2023 · 32 citations

  • Automotive engineering
  • Aerospace engineering
  • Engineering

  This study considers the aircraft configuration impacts of a liquid-hydrogen fuel-cell electric propulsion system when integrated into a single-aisle, transport-class aircraft having comparable performance capability of a Boeing 737-800. This study demonstrates that, given estimated developments in future components and subsystem technologies for a 2050 entry into service date, the design of an aircraft with a liquid-hydrogen fuel-cell–based propulsion system can be feasibly achieved while still meeting mission-level performance characteristics consistent with modern commercial aircraft throughout the anticipated lifetime of the aircraft. Key technologies that enable this are the purposeful integration of fuel cell thermal management, independent inlet compression to pressurize the air input to the fuel cells, and leveraging distributed electric propulsion advantages. Exploration into the impact of fuel cell power loss due to degradation is also presented. The results show a promising configuration of a liquid-hydrogen fuel-cell–based commercial aircraft to serve as a feasible replacement of narrow-body transport aircraft to help meet climate goals set for the aviation industry.

  PublisherDOI

• Trade-Space Assessment of Liquid Hydrogen Propulsion Systems for Electrified Aircraft

  2023-06-08 · 3 citations

  article

  View Video Presentation: https://doi.org/10.2514/6.2023-4345.vid In this paper we assess the feasibility of turbo-, hybrid-, and fully-electric civil aircraft propulsion systems. A modular optimization framework was developed to quantify system performance for a single-aisle transport aircraft with a mission similar to a Boeing 737-800. Various propulsion systems leveraging superconducting motors, boundary layer ingestion, distributed electric propulsion, high-temperature PEM fuel cells, and liquid hydrogen fuel were examined for the same notional aircraft. Aviation turbine fuel (ATF) and liquid hydrogen were compared using the payload-fuel energy intensity, PFEI, the fuel energy required per product of range and payload. For a given mission, the PFEI of the hydrogen-fueled fully-electric configuration examined was 4% higher than the ATF-burning twin turbo-fan baseline but produced zero carbon dioxide or nitrogen oxide emissions during flight. Relative to this baseline, a hydrogen-fueled turbo-fan had 24% lower PFEI, an ATF-burning turbo-electric propulsion system had 8% higher PFEI, and a hydrogen-fueled turbo-electric propulsion system had 14% lower PFEI. For the chosen mission, PFEI increased when adding fuel cells to a turbo-electric system or batteries to a fully-electric, fuel-cell-powered system.

  PublisherDOI

• Drag Reduction Techniques for eVTOL Configuration with Shrouded Rotors

  AIAA SCITECH 2023 Forum · 2023-01-19

  articleSenior author

  View Video Presentation: https://doi.org/10.2514/6.2023-0032.vid This study serves as a proof of concept of using flow directing mechanisms such as a semicircular obstacle instead of rotor doors to reduce drag of eVTOL configurations with shrouded lifting fans. Two drag reduction techniques, namely rotor doors and step, were integrated on current design of Rapper eVTOL. A step added to the pressure surface before the rotor opening will divert flow and prevents flow recirculation into the rotor duct, thus achieving drag reduction with lower integration complexity and weight penalties compared to rotor doors. Adding a step in front of the first rotor at pressure surface and covering the first duct opening at suction surface results in identical aerodynamic performances with respect to adding rotor doors to both openings of the first duct. Applying the same drag reduction technique to the first and second rotor ducts from the leading edge results in, on average, 76.2% of the performance ceiling of this configuration, compared to 48.7% of the performance ceiling with no drag reduction elements applied. Increasing height of the step will result in turbulent flow downstream, and increased drag introduced by flow stagnation at the step, thus observing negative impact on drag reduction due to separated flow. The drag reduction is shown to be three dimensional effects as similar drag reduction was not observed on two dimensional simulations over the same geometry and circular step coupled with circular cavity shows higher efficiency on drag reduction over straight step coupled with rectangular duct.

  PublisherDOI

• Aerodynamic Survey of Novel eVTOL Configuration Using SU2

  2022-08-01 · 1 citations

  reportOpen accessSenior author

  This report summarizes computational fluid dynamics (CFD) results of electric vertical takeoff and landing (eVTOL) geometries using the SU2 Reynolds-averaged Navier-Stokes (RANS) solver. Geometries were generated based on the Smart Transportation Infrastructure Initiative (STII) Rappor 15th iteration with various rotor-installment solutions. It was found that although open rotors installed on an underwing pylon were superior to shrouded rotors installed in a canoe, the canoe configuration would provide more potential for improvement, and using a canoe door to cover the first rotor opening would reduce the drag experienced by the canoe case below that upon the rod case. Rotor doors were found to be most efficient in reducing drag of the canoe case: Average drag reduction with covering the first rotor and all rotors was 66 and 165 counts, respectively. Changing rotor distributions along the chordwise direction had minimal impact on drag reduction, and placing rotors along the spanwise direction was not advised due to the increase of the projected frontal area. Increasing canoe chord length did not have significant impact on drag reduction; and if rotor doors were implemented, increasing canoe size had negative impact on drag. Rounding rotor edges did not change the aerodynamic performance of the canoe case but promotes vertical air intake when running lifting fans. Drag received by the canoe parabolically correlated to rotor diameter, with 126 counts of drag if the rotor diameter was 0 and 377 counts if the rotor diameter was 2.95 ft. Fuselage and tail added an average 179 counts of drag, and thus the aforementioned differences were still significant in the scale of aerodynamic properties of the full configuration.

  PublisherOA PDFDOI

• System-level Utilization of Low-grade, MW-scale Thermal Loads for Electric Aircraft

  AIAA AVIATION 2022 Forum · 2022-06-20 · 11 citations

  article

  View Video Presentation: https://doi.org/10.2514/6.2022-3291.vid This paper describes the analysis of a hydrogen fuel-cell-powered transport-category aircraft, similar in mission performance to a Boeing 737-800. The configuration examined produced peak waste heat loads up to 16 megawatts. Contemporary thermal dissipation systems, such as radiators, lead to a substantial drag contribution due to the large cooling surfaces required. In the paper, we 1) characterize the magnitude, occurrence, and effect of the thermal management challenge for fuel-cell-powered civil air transport, as exemplified through the CHEETA aircraft; 2) investigate multiple thermal management strategies that leverage thermal energy deposition from waste heat sources as a contribution within the propulsion system; and 3) demonstrate the impact of applying one of those strategies to enhance aircraft performance. We show that thermal system design for MW-scale electric aircraft cannot be considered as a simple drag penalty to be quantified after preliminary design is complete: power, propulsion, and thermal systems must be designed together.

  PublisherDOI

• Impact of LH₂Fuel Cell-Electric Propulsion on Aircraft Configuration and Integration

  AIAA Aviation 2019 Forum · 2021 · 14 citations

  • Automotive engineering
  • Aerospace engineering
  • Engineering

  View Video Presentation: https://doi.org/10.2514/6.2021-2409.vid This study considers the aircraft configuration impact of a liquid hydrogen/fuel cell electric propulsion system when integrated into a single-aisle, transport-class aircraft having consistent performance capability of a Boeing 737-800. This study demonstrates that, given reasonable developments in future component and subsystem technologies for a 2050 entry into service date, the design of an aircraft with a liquid hydrogen/fuel cell-based propulsion system can be feasibly achieved while still meeting mission-level performance characteristics consistent with modern commercial aircraft. While the use of hydrogen storage and fuel cell power systems does lead to an increase in maximum takeoff weight of the aircraft, relative to modern kerosene and turbofan-powered systems, the hydrogen fuel cell configuration benefits from leveraging distributed electric propulsion advantages, higher electrochemical efficiency than comparable thermal engines, and decreased thrust lapse rate with altitude when an independent inlet compression system is used. However, several challenges remain related to fuel cell system thermal management, requiring careful tradeoffs in fuel cell system composition, heat exchanger weight, and drag. Nevertheless, these results reveal the promising ability of a liquid hydrogen/fuel cell-based commercial aircraft to serve as a feasible replacement of narrow-body transport aircraft to help meet climate goals set for the aviation industry.

  PublisherDOI

Frequent coauthors

• Elias Waddington

  4 shared

• Phillip J. Ansell

  4 shared

• Donald Howe

  3 shared

• Stefanie Hirt

  3 shared

• Timothy Conners

  3 shared

• M. B. Bragg

  3 shared

• Kathleen Tacina

  3 shared

• Michael Bragg

  3 shared

Labs

• Experimental Robotics LabPI

Education

• Ph.D., Aerospace Engineering

  University of Illinois Urbana-Champaign

Awards & honors

• Stanley H. Pierce Faculty Award (2023)
• University of Illinois Department of Aerospace Engineering O…
• H. S. Stillwell A.A.E. Department Award (1999)
• Stanley H. Pierce College of Engineering Student Award (1999…
• Robert W. McCloy A.A.E. Department Award (1998)