Transition Within a Hypervelocity Boundary Layer on a 5-Degree Half-Angle Cone in Air/CO_2 Mixtures

Laminar to turbulent transition on a smooth 5-degree half angle cone at zero angle of attack is investigated computationally and experimentally in hypervelocity flows of air, carbon dioxide, and a mixture of 50% air and carbon dioxide by mass. Transition N factors above 10 are observed for air flows. At comparable reservoir enthalpy and pressure, flows containing carbon dioxide are found to transition up to 30% further downstream on the cone than flows in pure air in terms of x-displacement, and up to 38% and 140%, respectively, in terms of the Reynolds numbers calculated at edge and reference conditions

Transition Within a Hypervelocity Boundary Layer on a 5-Degree Half-Angle Cone in Air/CO_2 Mixtures

Laminar to turbulent transition on a smooth 5-degree half angle cone at zero angle of attack is investigated computationally and experimentally in hypervelocity flows of air, carbon dioxide, and a mixture of 50% air and carbon dioxide by mass. Transition N factors above 10 are observed for air flows. At comparable reservoir enthalpy and pressure, flows containing carbon dioxide are found to transition up to 30% further downstream on the cone than flows in pure air in terms of x-displacement, and up to 38% and 140%, respectively, in terms of the Reynolds numbers calculated at edge and reference conditions

Strategic Multilateral Dialogue on Biosecurity

Project on Advanced Systems and Concepts for Countering Weapons of Mass Destruction (PASCC) Naval Postgraduate School Defense Threat Reduction Agenc

Wi-Wave: Urban furniture for browsing internet contents in public spaces

Motivation - The socio-technical challenges created by Tangible User Interfaces with regards to invasiveness, privacy, visibility, control, etc. have been pointed out by several authors, but this case study focuses on two, more basic socio-technical aspects regarding the user's perspective and interaction with others. The paper presents a case study regarding the design of the interaction of interactive urban furniture, Wi-roni, for browsing information on the Web through a gesture-based interface in a public space. Research approach - The interaction modalities options were discussed and analyzed during the convergence phase, in which designers, technicians and users worked on the design of a prototype that could respond to the activity analysis and the shaping of physical factors. Findings/Design - The prototypes evaluation and assessment with users revealed many interesting aspects that mainly regard the interaction modality that changed significantly according to the shape of the artefact. Research limitations/Implications - Wi-roni is just a first exercise in this research direction. The design of other furniture will allows a more complete study regarding the emerging behaviour of the people involved in new and old convivial activities in public spaces. Originality/Value - We propose to respond to sociotechnical challenges by conceiving interaction modalities suitable for social activities complementing distant communication with in-presence communication and harmonizing "everywhere" with the specific values of a given location. Take away message - Designing unique artefact needs a big effort that is necessary in order to design a set of devices with an aesthetic and imaginative values