Advanced Hydrogen Aerospace Technologies and Design Online

Part 1: Hydrogen and Cryogenic Fundamentals (4 hrs)

THIS PART WILL COVER
An introduction to hydrogen fundamentals with an emphasis on cryogenic liquid hydrogen (LH2). A brief overview of safety considerations and key operations with LH2 will be covered focusing on aerospace applications.

Introduction

• Why hydrogen: the need for decarbonization, hydrogen as a multifaceted solution, LH2 characteristics and advantages
• Basic facts: energy content, storage options, spin states (ortho and para)
• LH2 history: jet engines, aircraft flights, liquefaction, space program, six decades of successful full scale operations
• Systems: system architectures, inputs, feedstocks, production, storage, generation, outputs, beneficial byproducts

Safety

• Drivers: fluid and material properties, cryogenic temperatures, phase change
• Mitigations: planning and training, providing ventilation, preventing leaks, eliminating ignition sources, other design and operational mitigations
• Operations: thermal management and understanding thermodynamic responses during key operations
• Pressure: controlling phase change during storage and operations

Fundamentals

• Environments: thermal, acceleration, mission/flight phases
• Properties: thermophysical, mechanical, data sources
• Thermodynamics: temperature and pressure responses
• Heat Loads: radiative boundaries, conductive paths, transient loads

Storage

• Tanks and dewars: single wall, double wall (dewars), sizing, packaging, integration
• Insulation systems: foam, perlite, aerogels, glass bubbles, multilayer insulation (MLI)
• Pressure control: passive design, venting, mixing, Joule-Thomson cooling
• Boil-off mitigation: cryo-refrigeration, reliquefaction, other active methods

Transfer

• Pressurization: self-pressurization, active pressurization, pressurant mass estimation, collapse factors
• Chilldown: transfer piping and components, receiving tanks, two-phase flow
• Filling: parameters affecting the fill process, minimizing losses, injection methods
• Sensors: temperature, pressure, fill level, flow, leak detection

Part 2: Why H2 for Fixed-Wing Design - designing the powertrain for fixed-wing operations, revisit efficiency and environment (6 hrs)

THIS PART WILL COVER
Why hydrogen in aviation with particular focus on CS25 large civil airplanes.

Starting from the benefits and the drawbacks of hydrogen as an aviation fuel, the potential aircraft economics and the possible technological choices will be presented. A case study will be then explored showing the main impacts in terms of powertrain design and its integration, aircraft systems, fuel system, safety, and overall aircraft design.

Notions of hydrogen as aviation fuel

• Colors of Hydrogen and its zero-emission potential
• Energy and gravimetric density compared to other sources
• Volatility and inflammability: the necessity of safety approach for design

Assessment of Technologies Readiness Level and Aircraft economics potential

• Potential powertrain architectures and relevant technology bricks
• Technological choices based on aircraft market segments
• Preliminary assessment of aircraft economics (hydrogen versus JETA-1)

A case study for the design: 50-passengers’ aircraft

• Weight and balance, structure
• Fuel system
• Aircraft systems
• Powertrain and aerodynamics

Recommended Reading

• Aerostructural Wing Optimization for a Hydrogen Fuel Cell Aircraft
• The Hydrogen-Electric Cessna Grand Caravan

Part 3: Hydrogen-Powered eVTOL Design (8 hrs)

• Introduction
• Design & Analysis of PEM Fuel Cell Systems
  • the i-v curve, hydrogen & air flow, H2 storage, balance of plant, weights & volume
• Design Software
• Examples
  • 80 kWe, 500 kWe, 500 kWe advanced for eVTOL
• Design & Analysis of eVTOL
  • Hover and forward flight, edgewise and tilting prop aircraft, sizing of eVTOL, integrated eVTOL-FC system sizing, batteries vs FC, hybrid power-sharing
• Examples
  • R-22, electric edgewise quadrotor, electric tilting proprotor
• Technology Drivers, Requirements, and Recommendations
• References
• Source Code and Input Decks

Part 3:Airport Compatibility and Hydrogen Infrastructure (2 hrs)

THIS PART WILL COVER
Airport compatibility criteria and how it influences aircraft design, perspectives on the hydrogen aircraft market and potential adoption timeline, facility requirements of hydrogen-powered aircraft and non-aircraft hydrogen technologies, hydrogen implementation challenges for airports, supply chain from production to the end user, regulatory aspects and policy implications.

Hydrogen Applications at Airports

• Overview of the airport ecosystem and of the potential hydrogen applications, including airside and landside.
• Airside users: aerial vehicles (from small H2eVTOLs to large commercial H2CTOLs), ground support equipment, and other support/maintenance vehicles.
• Landside components: cars, mass transit, freight and delivery, and other ground vehicles.
• Other applications (e.g., power generation, backup power, etc.).

Aircraft/Airport Compatibility and Facility Requirements

• Introduction to aircraft/airport compatibility and how it influences aircraft design.
• Review of airport compatibility criteria for the design of hydrogen-powered aircraft.
• Facility requirements of future hydrogen-powered aircraft (fuel cell electric and gas turbine aircraft).
• Operational safety issues with hydrogen-powered aircraft.

Market Perspectives and Adoption Timelines

• Review of key factors driving the adoption of hydrogen technologies and potential barriers. Impact of hydrogen implementation on the transition to zero-emission ground and air vehicles.
• Examination of potential market trends and adoption scenarios for hydrogen aviation technologies.
• Detailed review of different adoption scenarios and how they could shape the demand and the supply for hydrogen in aviation.

Supply Chain and Hydrogen Infrastructure

• Examination of the hydrogen supply chain from the production to the end user.
• Infrastructure requirements for hydrogen production, transport, storage, and dispensing.
• Hydrogen carriers (ammonia, liquid organic hydrogen carriers, etc.).
• Assessing the future demand in hydrogen across airport users.
• Airport, vertiport, and droneport planning and design considerations.
• Hydrogen infrastructure costs under different scenarios.

Airports as Hydrogen Hubs and Energy Nodes

• Perspectives on the emergence of a hydrogen economy at airports.
• Strategies available to address the local demand.
• Development of hydrogen implementation roadmaps.
• Engagement with stakeholders including airport operators, flight operators, government agencies, and hydrogen suppliers.
• Community engagement and environmental justice aspects.

Regulatory Aspects of the Hydrogen Supply

• Overview of current federal and state policies affecting hydrogen technologies.
• Ongoing rulemaking efforts in the United States and abroad.
• Analysis of the regulatory framework applying to the hydrogen supply chain.

Potential Path Forward

• Strategic transition of vehicle types for the most beneficial segments aligned with practical growth in hydrogen demand.
• Recommended next steps for further analysis and stakeholder collaboration to drive economic adoption of hydrogen at airports.

Recommended Reading

• ACRP Research Report 236: Preparing your Airport for Electric Aircraft and Hydrogen Technologies, National Academies, 2022
• ACRP Research Report 243: Urban Air Mobility: An Airport Perspective, National Academies, 2023
• ACRP Research Report 269: Enhancing Airport Access with Emerging Mobility, National Academies, 2024
• An Airport & Vertiport/Aircraft Compatibility Approach of Electric Vertical Takeoff & Landing Aircraft Design, Proceedings of Forum 79, Vertical Flight Society, April 2023
• Safety Considerations on the Operation of Electric Vertical and Takeoff Landing (VTOL) Aircraft at Airports and Vertiports, Proceedings of Forum 78, Vertical Flight Society, April 2022
• The Future of Airports: A Vision of 2040 and 2070, ENAC Alumni, 2024

Anubhav Datta is the Alfred Gessow Chair Professor of the Alfred Gessow Rotorcraft Center (AGRC) at the University of Maryland at College Park. He holds a M.S. and Ph.D. from the same institution. He joined AGRC as faculty in 2016 after nine years at the U. S. Army Aviation Development Directorate (ADD) at NASA Ames Research Center. Datta and his students study the fundamental sciences and engineering of advanced vertical lift aircraft, through wind-tunnel testing and comprehensive analysis, with electric flight, tiltrotors, and Mars helicopters as major thrust areas. Datta was the founder and former-Chair of the eVTOL Technical Committee of the Vertical Flight Society (VFS) and a founding member of its Hydrogen Council. He created the first short course on eVTOL in 2018 that is now taught at VFS and AIAA. He serves as the Chair of the AIAA Structural Dynamics Technical Committee, VFS Dynamics Committee, and as an Associate Editor of the Journal of the American Helicopter Society. He is a Technical Fellow of VFS.

Gaël Le Bris, CM, ENV SP, PE is Vice President, Aviation Planning and Technical Fellow with WSP. His experience includes complex airport planning and engineering projects in the United States and abroad. Prior to joining WSP, he was the Airside Development Manager at Paris-Charles de Gaulle International Airport, France. Mr. Le Bris is the Chair of the Transportation Research Board's AV090 Standing Committee on Aviation Safety, Security and Emergency Management. He serves on several committees and workgroups of organizations including AIAA, SAE International, The French-Speaking Airports (UAF&FA), and the Vertical Flight Society. He has authored various technical articles and publications including ACRP Research Report 236: Preparing Your Airport for Electric Aircraft and Hydrogen Technologies as well as The Future of Airports: A Vision of 2040 and 2070. He is the Principal Investigator for the ongoing ACRP Project 03-75: Preparing for Hydrogen at Airports.

Matt Moran is the Managing Member at Moran Innovation LLC, and previous Managing Partner at Isotherm Energy. He's been developing power and propulsion systems for more than 40 years; and break-through liquid, slush, and gaseous hydrogen systems since the mid-1980s. Matt was also the Sector Manager for Energy & Materials in his last position at NASA where he worked for 31 years. He's been a co-founder in seven technology startups; and provided R&D and engineering support to many organizations. Matt has three patents and more than 50 publications including the Cryogenic Fluid Management series. He also leads the monthly LH2 Era™ Webinar. Moran Innovation LLC develops technologies and systems for customers in the energy, transportation, aerospace, and defense industry sectors. An adaptive systems approach is applied for breakthrough innovation that accelerates system deployment and product launch. Recent contracts have included: NASA and commercial lunar landing systems development; venture-backed hydrogen systems for aircraft and vehicles; propulsion system trade studies for spacecraft and rocket engines; hydrogen-based microgrid and fueling system architectures; technology transfer and commercialization consulting.

Antonio Tripoli, an aerospace engineer, graduated from the University of Bologna (Alma Mater Studiorum) where he spent most of his career modifying, supporting, developing and exploring new concepts for civil transportation regional airplanes. After being a member of ATR engineering department in Flight Physics, Preliminary Design and R&T and Chief Engineering, he has been involved in the Universal Hydrogen company as Vice President of Engineering for the developments of hydrogen-powered regional aircraft.