Rainer Groh

Tag: Aerospace

  • Podcast Ep. #44 – Airflow is Building an eSTOL Aircraft for Middle-Mile Logistics

    Marc Ausman is the co-founder and CEO of Airflow, a California-based startup that is building an electric short-haul cargo aircraft. Marc holds a commercial pilot license, and among other endeavours, was previously the Chief Strategist for Airbus’ all-electric, tilt-wing vehicle demonstrator known as Vahana. Alongside four other former Vahana team members, Marc and the team at Airflow are building an aerial logistics network to move short-haul cargo quickly and cost effectively by using unused airspace around cities.

    Key to Airflow’s vision is electric short takeoff and landing (eSTOL). Airflow’s eSTOL aircraft require only a few hundred feet for takeoff and landing—about the length of a football field—which means that runways can be built almost anywhere, even under existing regulations. What is more, even larger rooftops that can fit more than three conventional helipads could feasibly be used as a runway. Given the aerodynamic efficiency advantages of fixed-wing aircraft over rotary vertical take-off and landing (VTOL) aircraft, Airflow have come-up with an interesting alternative concept to many other companies in the growing urban mobility sector.

    So in this episode of the Aerospace Engineering Podcast, Marc and I talk about:

    • Airflow’s vision of building the urban logistics network of the future
    • some of the misconceptions of eSTOL and eVTOL
    • the advantages of electric powertrains beyond reducing emissions
    • the technology Airflow is developing and challenges that need to be overcome
    • and striking a balance between financial and engineering incentives

    Selected Links from the Episode

  • Podcast Ep. #43 – Dr John Williams on Air-Breathing Rocket Engines

    Dr John Williams is an engineer at Lumentum where he works on the extreme challenges of sub-millimetre scale photonic circuits. For the purpose of this conversation, however, we will be discussing John’s former role as a design engineer at Reaction Engines, a UK company that is developing the Synergetic Air-Breathing Rocket Engine, also known as SABRE.

    The vision of SABRE is to build a new hypersonic engine that can operate both as an air-breathing jet engine and as a traditional rocket. This versatility means SABRE can be used as a propulsive platform for future hypersonic aircraft or to propel space planes into orbit. Furthermore, SABRE combines the unique fuel efficiency of a jet engine with the power and high-speed ability of a rocket. Having started at Reaction Engines early on when there were only two people in the design office, and later founding his own design and manufacturing company, John has many years of high-tech experience in the aerospace sector.

    In this episode of the Aerospace Engineering podcast, John and I talk about:

    • his background as an aerospace engineer
    • the benefits of an air-breathing rocket engine
    • the particular design challenges in realising this type of engine
    • and his lessons learned from high-tech development

    Selected Links from the Episode

  • Podcast Ep. #27 – A Masterclass on Friction Welding with TWI’s Bertrand Flipo

    In this episode I am speaking to Bertrand Flipo from The Welding Institute in Cambridge, UK. TWI Ltd has a long history of innovation in welding research, having been established as the British Welding Research Association in 1946. TWI Ltd is a world leader in research on friction welding and has been at the forefront of many modern friction welding processes.

    Briefly put, friction welding is a joining technique that does not melt the parts to be joined. Instead, two components are rubbed together to create heat through friction, and high pressure is then applied to squeeze the two pieces together. During this process the material plastically deforms and the high pressure causes the components to be fused together. Advantages of the process are fast joining times, typically on the order of a few seconds; relatively small heat-affected zones; and because friction welding techniques are melt-free, the material’s microstructure can be maintained. I personally learned a lot during the recording of this episode, and Bertrand and his colleagues were very gracious to introduce me to the ins and outs of friction welding. So in this episode you will learn about:

    • the differences between different friction welding techniques
    • the main advantages of friction welding and the challenges to keep in mind
    • some of the aerospace applications where friction welding is a game-changer
    • and much, much more

    Selected Links from the Episode

  • Podcast Ep. #21 – Prof. Paul Withey on Single-Crystal Superalloys for Jet Engine Turbines

    Paul Withey is the Professor of Casting at the School of Metallurgy and Materials of the University of Birmingham, UK. Before joining the University of Birmingham in 2018, Paul worked at Rolls Royce for 21 years developing new superalloys and manufacturing processes for gas turbine components. As an Engineering Associate Fellow, Paul was a member of a select group of the top 100 specialist engineers across all engineering disciplines within Rolls Royce, and in 2015, Paul and his team were awarded the highest technical award within Rolls-Royce; the Sir Henry Royce Award.

    Paul’s particular expertise lies in investment casting of aerospace metals, especially of high-temperature superalloys used in the hot turbine stages of modern jet engines. Throughout his career at Rolls-Royce, Paul has developed and optimised manufacturing processes for single-crystal turbine blades with a total of 14 patents to his name. Despite phenomenal advances in materials technology, a number of questions with regard to how the turbine blade shape, materials and process parameters interact remain unanswered, and these questions form the basis of Paul’s ongoing research. In this episode, Paul and I discuss:

    • the unique differences between research in academia and industry
    • what single-crystal superalloys are and how they are manufactured
    • why single-crystal superalloys are a critical technology for modern jet engines
    • and the research questions that Paul is currently trying to answer

    Selected Links from the Episode

  • Podcast Ep. #19 – Manuel Schleiffelder on the Hound Project and Metal Matrix Composites for Rockets

    Today I am speaking to Manuel Schleiffelder, an aerospace engineer based in Vienna, Austria. Manuel has a background in designing and building experimental rockets with the student space team of the Technical University in Vienna, known as the Hound Project. I spoke to Manuel after he returned from a trip to the Black Rock Desert, where the Vienna space team tested their newest two-stage experimental rocket. Manuel has a very broad background in space engineering having worked on projects varying from spacecraft design of lunar landers and systems engineering of rocket propulsion systems, to his newest research project in materials science: metal matrix composites.

    In a classic rocket engine the exhaust gases have a speed limit of exactly Mach 1 (the speed of sound) at the narrowest portion of the nozzle—the so-called choking condition. Since the speed of sound increases with temperature, hotter combustion means the exhaust gases can be expelled from the rocket at greater velocity. While the speed of sound in air at room temperature is typically around 1200 km/hr (745 mph), the speed of sound in the hot exhaust gases of a rocket can be more than 5 times this value. So even though we want our rocket engine to run as hot as possible, there are obvious practical limitations in terms of the ability of materials to withstand these extreme temperatures. For this reason, most rocket engines use some form of cooling to keep the material temperature within reasonable bounds. Manuel is currently developing metal matrix composite materials (carbon fibres embedded within a metal matrix) that are strong enough to withstand the extreme temperatures without the additional mass and complexity of a cooling system. In this episode, Manuel and I talk about

    • his background in aerospace engineering
    • the rockets that the Vienna student space team are building and testing
    • and the advantages and challenges of developing metal matrix composites for rocket engines.

    Selected Links from the Episode

  • Podcast Ep. #12 – The Perlan Project: Soaring to the Edge of Space

    This episode features an in-depth look at the Perlan Project. The mission of the Perlan Project is to fly an engineless aircraft to the edge of space, in this case, by taking advantage of an aerodynamic phenomenon known as wave lift. Not only is soaring to 90,000 feet an audacious goal, but on top of that, the Perlan Project is a worldwide collaborative project run entirely by aviation enthusiasts, scientists, engineers and adventurous pilots. No one has ever soared to the edge of space in a glider and so the Perlan engineers are venturing into unchartered aviation territory on their own. On this episode of the Aerospace Engineering Podcast I speak to Project Manager Morgan Sandercock and Flight Test Engineer Alan Lawless about:

    • the genesis and history of the Perlan Project
    • how one goes about designing, manufacturing and testing a glider that is to fly to the edge of space
    • past success stories
    • and the team’s future plans for breaking aviation records.

    In case you personally want to support the Perlan Project as a donor, you can do so on the Perlan Project donor page.

    Selected Links from the Episode

  • Podcast Ep. #11 – Dr Priyanka Dhopade on Jet Engine Optimisation and Women in Engineering

    Priyanka Dhopade received her PhD from the University of New South Wales in Canberra, Australia and was the recipient of the Zonta Amelia Earhart Fellowship award, awarded annually to the 35 most outstanding female aerospace PhD students worldwide. Since 2013 she has been researching the thermodynamics of jet engines in the Thermofluids Institute at Oxford University. Priyanka is an expert in computational fluid dynamics modelling of heat transfer, aerodynamics and aero-elasticity in jet engines. She is currently leading the modelling campaigns for various projects in collaboration with industry partners relating to turbine and compressor tip clearance control, turbine internal cooling and active flow control. In this episode, Priyanka and I talk about:

    • the challenges of improving the efficiency of current gas turbines
    • the intricacies of fluid dynamics modelling
    • and a topic particularly close to her heart, the diversity challenge in STEM fields.

    Selected Links from the Episode

  • Podcast Ep. #9 – Faradair Founder Neil Cloughley on the Bio-Electric Hybrid Aircraft and Regional Aviation

    Neil Cloughley is the founder and managing director of Faradair, the UK’s leading hybrid aviation programme. Neil has a broad background in the aviation industry ranging from aircraft re-marketing and aircraft leasing to starting his own aircraft consultancy business, which found him working with the world’s major airlines, OEMs and trailblazing companies like Virgin Galactic. Neil’s father developed one of the most advanced unmanned aerial vehicles of the early 1990s, and had a flying prototype before the General Atomics MQ-1 Predator entered service in 1995. Unfortunately, as a result of being slightly ahead of its time, and due to a lack of funds and unfortunate timing, ASVEC UK had to close its doors.

    Neil is now stepping into his father’s footsteps and building the bio-electric hybrid aircraft (BEHA) drawing from many of the lessons he learned from his father. The BEHA is a six-passenger aircraft with a hybrid gas and electric propulsion system, and is to be used for regional travel of around 200 miles. The BEHA has an unconventional design with a triple-staggered wing, an all-composite airframe and a ducted propeller. These design decisions reflect the three key specifications that need to be met to make regional inter-city flight a reality: minimising noise, emissions and operational costs. In this conversation, Neil and I talk about

    • the engineering behind BEHA
    • the challenging economics of new aviation businesses
    • his long-term vision for a regional Uber-like taxi service in the sky
    • and much, much more

    Selected Links from the Episode

  • Podcast Ep. #8 – Rocket Lab’s Lachlan Matchett on Democratising Access to Space and the Rutherford Rocket Engine

    In this episode I am talking to Lachlan Matchett, who is the VP of Propulsion at Rocket Lab. Rocket Lab is a startup rocket company with the mission of removing barriers to commercial space by frequent launches to low-earth orbit. The current conundrum of many space technology companies that want to launch small satellites into space is that there is no dedicated launch service tailored to their needs. This is where Rocket Lab enters the picture. To provide small payloads with a flexible and dedicated launch vehicle, Rocket Lab has developed the Electron rocket. The Electron is a two-stage rocket that can be tailored to unique orbital requirements and provides frequent flight opportunities at personalised schedules.

    In terms of the engineering, there are many interesting features to the Electron rocket, but one of the key innovations is the Rutherford engine that Lachlan Matchett and his team have developed over the last five years. Rutherford is the first oxygen/kerosene-powered engine to use 3D printing for all primary components. In fact, the Rutherford engine can be printed in an astounding 24 hrs, and this is one of the driving factors behind Rocket Lab’s cost efficiency and high target launch frequency. So in this episode, Lachlan and I talk about:

    • Rocket Lab’s business model
    • their recent launch success in Jan 2018
    • some of the engineering highlights of the Rutherford engine
    • and Rocket Lab’s plans for the future

    Selected Links from the Episode

  • Podcast Ep. #7 – Dr Valeska Ting on Smart Nanomaterials for Hydrogen Storage

    Today’s episode features Dr Valeska Ting who is a Reader in Smart Nanomaterials at the University of Bristol and is researching the use of nanoporous materials for hydrogen storage. Using hydrogen as a fuel source has many benefits. Due to its excellent energy density, hydrogen has long been hailed as an alternative to fossil fuels but it’s also an excellent means of storing renewable energy from solar or wind sources. One of the challenges of storing hydrogen is its low density, meaning that large volumes are required to store efficient amounts of hydrogen to be able to use it as a fuel. This is precisely where Valeska’s research enters the picture. The nanoporous materials that she is working on can increase the density of hydrogen by a factor of a 1000, and therefore provide a key stepping stone towards more efficient hydrogen-powered vehicles. In this episode, Valeska and I talk about multiple aspects of this technology including:

    • what nanoporous materials are and how they work
    • how they can be used to create multifunctional materials
    • what scientific challenges she is addressing to scale-up and improve their performance, and
    • how they could be applied to design lighter hydrogen tanks for cars, aircraft or even rockets

    Selected Links from the Episode