Скачать с ютуб Understanding the Vortex Ring State - by way of experiment and simulation to a theory в хорошем качестве

Understanding the Vortex Ring State - by way of experiment and simulation to a theory

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. It involves the collapse of the wake of one or more of the vehicle's rotors from its usual regular, ordered state into a highly disordered, re-circulating flow. The pilot usually experiences the onset of the Vortex Ring State as a relatively sudden reduction in the lifting ability of the rotor that can be very difficult to counteract. Although the Vortex Ring State was first characterised in the earliest days of helicopter flight, the physical mechanisms that govern the phenomenon are complex, and the link between the design of the aircraft and its behaviour in the Vortex Ring State is still only partially understood. During this talk, our current understanding of the Vortex Ring State will be examined, and the story will be told of how data from laboratory and numerical experiments were combined 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, we will see how a theory emerged that is now used 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 will be covered in detail and some generalisations to the next generation of rotorcraft that are on the drawing boards will be presented. Speaker Details Dr Richard E Brown CEng FIMechE FRAeS - Sophrodyne Aerospace Richard obtained his MSc, in the very early days of CFD, from the Cranfield Institute of Technology and has a PhD in Theoretical Fluid Mechanics from the University of the Witwatersrand in Johannesburg. After starting his aeronautical career in the South African aviation industry working on the aerodynamics of the Rooivalk helicopter, he moved to the UK in 1997. After nearly a decade at the Department of Aeronautics at Imperial College in London, he relocated to the University of Glasgow in 2006 as full professor and director of the Glasgow Rotorcraft Research Laboratory. In 2010 he moved across town to the University of Strathclyde to found the Centre for Future Air Space Transportation Technology - where he led a programme of research that aimed to extend the range of techniques that would be available for the design and analysis of the next generation of hypersonic trans-atmospheric air transport vehicles. He is perhaps best known as the originator of the Vorticity Transport Model - a specialised CFD tool for understanding aircraft aerodynamics and flight mechanics where the effects of aerodynamic interactions between the aircraft's various components are especially important - and is the author of over 100 technical papers on various aspects of aeronautics from flight at very low Reynolds numbers to flight at hypersonic speeds. Many of these papers were written in collaboration with the fourteen PhD students that he feels very privileged to have supervised during his quarter century in academia. In 2016 he left academia to form Sophrodyne Aerospace, where he has been helping a range of companies to develop and adopt the new generation of methodologies that they will need to design the next generation of ultra-efficient, environmentally-friendly flight vehicles. Find out more about Richard's work at https://sophrodyne-aerospace.com/