Dr Brown will present his paper, titled "Do eVTOL Aircraft create an inherently more problematic Downwash than Conventional Helicopters?" at this year's European Rotorcraft Forum, to be held from 5 - 7 September 2023 in Bückeburg, Germany.

When a rotorcraft is operated at low enough height above the ground, the aerodynamic interaction with the surface below causes the flow from its rotors to expand out across the ground as a layer of rapidly-moving airflow, called its outwash. If this outwash is strong enough, it can cause significant upset to bystanders and nearby infrastructure. A recent numerical study by Dr Brown has shown that the shape and strength of the outwash that any multi-rotor eVTOL aircraft will generate is strongly dependent on the layout of its rotors, amongst other factors.

Indeed, several aspects of the behaviour of the outwash that is created by eVTOL aircraft may come as a surprise to the rotorcraft community - where intuition is largely based on experience with conventional helicopters. In his paper, Dr Brown thus discusses the implications of his findings for the prospective operators of this type of aircraft, as well as for the designers of the vertiports from which these aircraft will fly.

We will publish a copy of the paper on our website shortly after Dr Brown's presentation. In the mean time, the tab below will take you to the conference website.

Dr Brown travelled to the USA in May to attend the 79th Annual Vertical Fight Society Forum and Technology Display, where he presented his award-winning paper "Are eVTOL Aircraft Inherently more susceptible to the Vortex Ring State than Conventional Helicopters?" at a special session of the conference.

Richard's paper was awarded 2022's prestigious Ian Cheeseman Prize, given annually to the best technical paper presented at that year's European Rotorcraft Forum.

Richard's work shows how our current understanding of the Vortex Ring State applies to the design of modern eVTOL aircraft. The paper has attracted considerable interest from the community through highlighting a range of effects that designers and operators should be aware of in order to ensure the safety of these vehicles.

The tab below will take you to our VRS Resource page from where you can download a copy of Richard's paper.

Dr Brown was recently a panellist on the final day of the 2023 Helicopter Investor Conference, held from 22-23 March at the Royal Garden Hotel in London.

The topic for discussion was "Is the future electric? Helicopters and electric VTOL aircraft - what is the future and is there room for both?" Richard was joined by Frank Liemandt, European Rotors, Jean-Marc Youkhana, Uplifting Aviation, Nigel Leishman, LCI, and Tim Chun-hing Li, from Ascend by Cirium, for a lively debate on the technical and commercial future of the VTOL community.

The tab below will take you to the website for the conference.

Dr Brown presented his new public lecture "Back to the Future - How can Helicopter Experience inform Future Rotorcraft Design?" to the Prestwick branch of the Royal Aeronautical Society in their first live event of the year, held at at Ayr College on 13 February.

He spoke from his own experience of thirty years as a helicopter aerodynamicist, and showed how dealing with the effects of aerodynamic interactions within the system remains one of the biggest challenges to designing a rotorcraft that has acceptable performance, stability and control.

Dr Brown explained how the challenge is to abstract the historical record into a body of knowledge that can be used to design the next generation of rotorcraft. He showed how specialised modern numerical techniques can be used to contextualise what we know from existing experimental and flight test data. The outcome might be a framework that can be used by the designers of modern eVTOL aircraft to predict and overcome the aerodynamic issues that are presented by this new class of rotorcraft.

Use the tab below if you would like to schedule Dr Brown to present this lecture to your organisation.

Dr Brown presented his lecture "Shock Waves and the Design of Future Spacecraft" to GU Rocketry, a team of enthusiastic young students based in the School of Engineering at Glasgow University.

The talk was based on his experience as Director of the Centre fof Future Air-Space Transportation Technology, where his research group was engaged in developing computational methods that could predict the aerodynamic and thermal loads that spacecraft will encounter during their re-entry into the earth's atmosphere.

Dr Brown showed how sensible spacecraft design is constrained by the ability of the engineer's tools to be able to calculate accurately the properties of the flows that are generated by the vehicle during re-entry, and how, from early beginnings with vehicles that had spherical or conical geometry, we can now design our vehicles with shapes that are complex enough for the craft to behave very much more like a high-speed aircraft than a purely ballistic device.

He finished by explaining how the history of NASA's Space Shuttle gives a salutary warning against over-confidence in the predictive capabilities of our tools.

Use the tab below if you would like to schedule Dr Brown to present this lecture to your organisation.

Just before Christmas 2022 we learned that Dr Brown had been awarded the prestigious Ian Cheeseman Prize, given annually to the best technical paper presented at that year's European Rotorcraft Forum.

The prize will allow Dr Brown to travel to the 79th Annual Vertical Fight Society Forum and Technology Display, to be held this May in West Palm Beach, Florida, USA, where he will present his paper "Are eVTOL Aircraft Inherently more susceptible to the Vortex Ring State than Conventional Helicopters?" at a special session of the conference.

The Vortex Ring State is a particularly hazardous operating regime that a rotorcraft can enter into during the critical descent and landing phases of flight. Richard's paper shows how our current understanding of the phenomenon applies to the design of modern eVTOL aircraft, and highlights a range of effects that designers and operators should be aware of in order to ensure the safety of these vehicles.

The tab below will take you to our VRS Resource page from where you can download a copy of his paper.

Dr Brown presented an updated version of his paper, titled "Are eVTOL Aircraft Inherently more susceptible to the Vortex Ring State than Conventional Helicopters?" at this year's EASA Rotorcraft and VTOL Symposium, to be held from 8 - 9 November 2022 in Cologne, Germany.

The paper built on his earlier presentation at the European Rotorcraft Forum by showing some of the real problems that might be induced in the design of eVTOL aircraft if their physical characteristics and limitations are not held firmly in mind when drawing up the regulations governing the vertiports from which they will operate.

The tab below will take you to the online recording of Dr Brown's presentation.

Dr Brown has presented a paper titled "Are eVTOL Aircraft Inherently more susceptible to the Vortex Ring State than Conventional Helicopters?" at this year's European Rotorcraft Forum, held from 6 - 8 September 2022 in Winterthur, Switzerland.

The Vortex Ring State is a particularly hazardous operating regime that a rotorcraft can enter into during the critical descent and landing phases of flight. Richard's paper shows how our current understanding of the phenomenon applies to the design of modern eVTOL aircraft, and highlights a range of effects that designers and operators should be aware of in order to ensure the safety of these vehicles.

The tab below will take you to our VRS Resource page from where you can download a copy of his paper.

During his online lecture to the Bedford branch of the Royal Aeronautical Society, Dr Brown examined our current understanding of the Vortex Ring State - a particularly hazardous operating regime that a rotorcraft can enter into during the critical descent and landing phases of flight.

He first told the story of how data from laboratory and numerical experiments was combined in the mid-'00s to change our understanding of the basic mechanisms at the heart of the phenomenon. As an illustration of how mathematical abstraction can lend deep insights into practical engineering problems, he then showed how a theory was developed that is now used throughout the world to help aircraft designers to understand the susceptibility of their creations to this potentially dangerous aerodynamic phenomenon.

The specific case of the V-22 Osprey tilt-rotor was covered in detail, and Dr Brown then went on to discuss the implications of his research for the next generation of rotorcraft that are on the drawing boards.

The tab below will take you to a recording of the event.