Numerical analysis of a high velocity oxygen fuel (HVOF) process

The HVOF process is used for coating protective layers on surfaces exposed to corrosion and wear. This process involves a supersonic two-phase flow of gas-solid particles. The main objective of this thesis is to explore certain key factors that influence the process efficiency such as gas-particle interactions, particle in-flight conditions, and particle loading. To study the effect of gas-particles interactions, a Lagrangian approach which tracks individual particles in the continuous gas, is used. The supersonic gas flow leaving an HVOF nozzle is over-expanded and its adjustment to the atmospheric pressure results in shock diamonds formation, while flow impingement on a substrate results in bow-shock development. Both the shocks are responsible for affecting the particle conditions. The strength and location of bow shock vary for different substrate geometries and stand-off distances. In this work, various particle sizes impinging on different substrate configurations are simulated and the particle interactions with both the shocks are presented in detail. To find the effect of particle loading on the gas phase, a dense particulate phase scenario is assumed. A fully Eulerian approach, which treats the particles as a fluid, is used to simulate the HVOF process and the two-phase flow characteristics were investigated for various particle loadings. The particulate phase was found to be dense near the nozzle centerline and dilute near the wall. In the particle-dense region, the gas phase characteristics were found to be severely affected, which significantly affects the particle velocit

Planet.Health: An Ecosystem Approach to Imagine and Coordinate for Planetary Health Futures

Planet.Health addresses imagination and coordination challenges for planetary health through innovative approaches to social organising. This report presents the findings from the inaugural Planet.Health event in 2022, including the Planet.Health unconference. An unconference is a participant-driven event format that provides flexibility for emergent ideas and connections. In this (un)conference report, we share the challenges, achievements, and lessons learned during the initial year of activities in the leadup to and following the Planet.Health unconference event. We also discuss how the intersection of web3 and planetary health—a major focus of the first year—provides an alternative lens for envisioning, innovating, and coordinating beyond conventional social and institutional frameworks. We explore the potential impact of web3 technologies and decentralised social, economic, and financial networks and highlight the implications of these approaches for addressing planetary crises and supporting a flourishing human–environment relationship. As a new contribution to the planetary health field, this work emphasises the importance of building decentralised systems to foster creative actions and inspire global engagement for planetary wellbeing. The report concludes with some practical insights on how we begin to build and sustain decentralised social networks, including a discussion of the benefits and limitations of these approaches

Planet.Health : an ecosystem approach to imagine and coordinate for planetary health futures

Planet.Health addresses imagination and coordination challenges for planetary health through innovative approaches to social organising. This report presents the findings from the inaugural Planet.Health event in 2022, including the Planet.Health unconference. An unconference is a participant-driven event format that provides flexibility for emergent ideas and connections. In this (un)conference report, we share the challenges, achievements, and lessons learned during the initial year of activities in the leadup to and following the Planet.Health unconference event. We also discuss how the intersection of web3 and planetary health—a major focus of the first year—provides an alternative lens for envisioning, innovating, and coordinating beyond conventional social and institutional frameworks. We explore the potential impact of web3 technologies and decentralised social, economic, and financial networks and highlight the implications of these approaches for addressing planetary crises and supporting a flourishing human–environment relationship. As a new contribution to the planetary health field, this work emphasises the importance of building decentralised systems to foster creative actions and inspire global engagement for planetary wellbeing. The report concludes with some practical insights on how we begin to build and sustain decentralised social networks, including a discussion of the benefits and limitations of these approaches