A multi-physics method for fracture and fragmentation at high strain-rates

This work outlines a diffuse interface method for the study of fracture and fragmentation in ductile metals at high strain-rates in Eulerian finite volume simulations. The work is based on an existing diffuse interface method capable of simulating a broad range of different multi-physics applications, including multi-material interaction, damage and void opening. The work at hand extends this method with a technique to model realistic material inhomogeneities, and examines the performance of the method on a selection of challenging problems. Material inhomogeneities are included by evolving a scalar field that perturbs a material's plastic yield stress. This perturbation results in non-uniform fragments with a measurable statistical distribution, allowing for underlying defects in a material to be modelled. As the underlying numerical scheme is three dimensional, parallelisable and multi-physics-capable, the scheme can be tested on a range of strenuous problems. These problems especially include a three-dimensional explosively driven fracture study, with an explicitly resolved condensed phase explosive. The new scheme compares well with both experiment and previous numerical studies

Critical Reflections on Building a Community of Conversation about Water Governance in Australia

Water governance has emerged as a field of research endeavour in response to failures of current and historical management approaches to adequately address persistent decline in ecological health of many river catchments and pressures on associated communities. Attention to situational framing is a key aspect of emerging approaches to water governance research, including innovations that build capacity and confidence to experiment with approaches capable of transforming situations usefully framed as ‘wicked’. Despite international investment in water governance research, a national research agenda on water governance was lacking in Australia in the late 2000s as were mechanisms to build the capacity of interdisciplinary and transdisciplinary research and collaborative policy practice. Through a two-year Water Governance Research Initiative (WGRI), we designed and facilitated the development of a community of conversation between researchers concerned with the dynamics of human-ecological systems from the natural sciences, humanities, social sciences, policy, economics, law and philosophy. The WGRI was designed as a learning system, with the intention that it would provide opportunities for conversations, learning and reflection to emerge. In this paper we outline the starting conditions and design of the WGRI, critically reflect on new narratives that arose from this initiative, and evaluate its effectiveness as a boundary organisation that contributed to knowledge co-production in water governance. Our findings point to the importance of investment in institutions that can act as integrative and facilitative governance mechanisms, to build capacity to work with and between research, policy, local stakeholders and practitioners

Governing irrigation renewal in rural Australia

Irrigation renewal schemes are taking place globally for water conservation and gains in agricultural productivity, as competition for water resources increases. The publically-funded renewal of irrigation infrastructure is a key platform of water reform in Australia’s Murray-Darling Basin; it is considered by some to be a policy that contradicts market-based approaches. In this Australian study, we examine an irrigation renewal scheme in northern Victoria resulting from a large investment by the State and Federal Governments. The long historical development of infrastructure and institutions for irrigation in the region led to technological lock-in and exposure to international terms of trade and climate change. From interviews with water professionals involved in the region, three key themes were identified through an adapted grounded theory approach: (1) a lack of an appropriate platform for fostering community involvement in what was a large-scale investment of public money; (2) issues in the way that water losses and savings were calculated; and (3) contradictions in policies for water buyback and irrigation renewal that lead to some irrigators being disadvantaged. To better understand the situation, we also applied a theoretical lens based on social learning. We conclude that the framing of a water ‘crisis’ was used to the benefit of some irrigators in attracting large-scale investment of public funds for irrigation renewal. The proposed solution, a technologically-driven irrigation renewal scheme, was implemented at a pace that didn’t match the planning horizons for many, leading many to exit from irrigated agriculture. Systemic insights for the design and implementation of irrigation renewal schemes internationally are highlighted

A6_6 Lunar-tising

Lunar advertising, although a Sci-Fi concept, has caught the attention of company executivesbefore. In this paper, the authors examine the feasability of Moon advertising using lasers, andexamine the mechanics behind this. The paper nds that the power required to beam a messageon the Moon's surface are in the order of magnitude of 10^12 W, but any combination of normaloptical lasers can be used as there is no special requirements

A6_4 The Hyperloop through the centre of the Earth

This paper describes how a Hyperloop style pod would travel through a low pressure tunnel straight through the Earth. The equations of motion for the pod in an airless tube are derived, and the total travel time is found, agreeing with the commonly quoted value of 42 minutes. A peak velocity of about 8000 ms−1 was also calculated. Furthermore, a numerical solution to an Earth bisecting tube with low air resistance was found, and graphed to show an exponential decay in amplitude of trajectory. the loss of velocity every oscillation meant the pod would not reach anywhere near the other side of the planet

A6_1 The Suitability of Russell's Teapot for Liquid Containment at an Appropriate Temperature

Russell's teapot is a hypothetical teapot floating in space between Earth and Mars. The maximum and minimum temperature of tea stored in this pot was found to be 277 K and 225 K respectively using the Stefan-Boltzmann law. An optimal tea storage orbit radius is calculated to be 83.2 million km, just inside the orbit of Venus

A6_5 Floating Cities

In this paper we describe the construction of a floating habitat as described by Buckminster Fuller in the 1930’s. We first examine a a 2 km wide sphere that has been heated by 1◦C and find it generates a lift of 1.64×108 N. We further examine the feasibility of carbon nanotubes as a construction material and find that they are able to withstand the tension from the interior stresses of the sphere. Lastly, we consider the general case with variable radii and temperature, and find that even the smaller spheres can house thousands of people

A6_3 Taking the Moon to Mars

We apply the Method of Patched Conics to estimate the trajectory the Moon would take if it wereto be removed from its current orbit and placed in the same orbit at Mars. We calculate thatthe velocity changes at Earth and Mars required for such a trajectory are 1906 m/s and 1356 m/srespectively. We determine that it would take one coal burning power plant in excess of 11012years to produce enough energy for just one velocity change, making the concept predictablyunfeasible with current technology

A6_2 How Hot is Tatooine

Tatooine is a fictional terrestrial planet from the Star Wars universe which orbits a set of binary stars. By considering the classification of its Suns, Tatoo I and Tatoo II, and the planets orbital period we were able to find the radius of Tatooine’s orbit, 1.15 Au. It was then possible to work out the varying solar constants for Tatooine depending on its position relative to both Suns, allowing us to calculate an average daytime temperature range of 42.3 celcius to −10.7 celcius