1,024 research outputs found
“It gave me a much more personal connection”: Student generated podcasting and assessment in teacher education
No full textThis paper reports on a qualitative case study of an online initial teacher education class in New Zealand, exploring the potential of student-generated podcasts as a form of interactive formative assessment. Findings from interviews with teaching staff indicate that podcasting was useful for supporting multimodal learning valuing student voice and reflections. Podcasting enhanced the affective and relational connections in the online class, and empowered students to develop technical skills and confidence relevant in their teaching careers. As such, this study positions educators as future makers and as leaders in a climate of change. We suggest implications for student-generated podcasts in similar contexts
Non-linear free-surface flows about blunt bodies / by Lawrence K. Forbes
No full textTypescript (photocopy)109 leaves : ill. ; 30 cm.Thesis (Ph.D.)--University of Adelaide, Dept. of Applied Mathematics, 198
Waves in two-layer shear flow for viscous and inviscid fluids
No full textAbstract not availableMichael J. Chen and Lawrence K. Forbe
Accurate methods for computing inviscid and viscous Kelvin-Helmholtz instability
No full textAbstract not availableMichael J. Chen and Lawrence K. Forbe
Bow and stern flows with constant vorticity
No full textFree surface flows of a rotational fluid past a two-dimensional semi-infinite body are considered. The fluid is assumed to be inviscid, incompressible, and of finite depth. A boundary integral method is used to solve the problem for the case where the free surface meets the body at a stagnation point. Supercritical solutions which satisfy the radiation condition are found for various values of the Froude number and the dimensionless vorticity. Subcritical solutions are also found; however these solutions violate the radiation condition and are characterized by a train of waves upstream. It is shown numerically that the amplitude of these waves increases as each of the Froude number, vorticity and height of the body above the bottom increases
Optimal fluid injection strategies for in situ mineral leaching in two-dimensions
No full textThis paper examines the ground-water flow problem associated with the injection and recovery of certain corrosive fluids into mineral bearing rock. The aim is to dissolve the minerals in situ, and then recover them in solution. In general, it is not possible to recover all the injected fluid, which is of concern economically and environmentally. However, a new strategy is proposed here, that allows all the leaching fluid to be recovered. A mathematical model of the situation is solved approximately using an asymptotic solution, and exactly using a boundary integral approach. Solutions are shown for two-dimensional flow, which is of some practical interest as it is achievable in old mine tunnels, for example
Withdrawal from a two-layer inviscid fluid in a duct
No full textThe steady simultaneous withdrawal of two inviscid fluids of different densities in a duct of finite height is considered. The flow is two-dimensional, and the fluids are removed by means of a line sink at some arbitrary position within the duct. It is assumed that the interface between the two fluids is drawn into the sink, and that the flow is uniform far upstream. A numerical method based on an integral equation formulation yields accurate solutions to the problem, and it is shown that under normal operating conditions, there is a solution for each value of the upstream interface height. Numerical solutions suggest that limiting configurations exist, in which the interface is drawn vertically into the sink. The appropriate hydraulic Froude number is derived for this situation, and it is shown that a continuum of solutions exists that are supercritical with respect to this Froude number. An isolated branch of subcritical solutions is also presented
A study of nonlinear waves and resonance in intrusion flows
No full textA stratified intrusion flow is considered in which there are three moving (horizontal) fluid layers and two interfaces. The top and bottom layers move with different speeds and may even move in opposite directions, producing an exchange flow. The middle layer is in motion relative to the outer two, and possesses shear so that the speed in the three-fluid system is continuous when the interfaces are both unperturbed. The flow configuration supports the propagation of periodic waves. A linearized analysis for small wave amplitudes is presented. This is compared to some nonlinear periodic solutions found numerically using a Fourier technique. Such solutions permit nonlinear resonances between the various solution modes and these have been computed extensively.
References P. O. Rusas and J. Grue. Solitary waves and conjugate flows in a three-layer fluid. European Journal of Mechanics, B/Fluids, 21:185--206, 2002. doi:10.1016/S0997-7546(01)01163-3. L. K. Forbes, G. C. Hocking, and D. E. Farrow. An intrusion layer in stationary incompressible fluids: Part 1: Periodic waves. Euro. Jnl of Applied Mathematics, 17:557--575, 2006. doi:10.1017/S0956792506006711. G. C. Hocking and L. K. Forbes. A note on the flow of a homogeneous intrusion into a two-layer fluid. Euro. Jnl of Applied Mathematics, 18:181--193, 2007. doi:10.1017/S0956792507006924. H. Michallet and F. Dias. Non-linear resonance between short and long waves. Proc. of the 9th International Offshore and Polar Engineering Conference, pages 193--198, 1999. http://cat.inist.fr/?aModele=afficheN&cpsidt=1174804. D. I. Pullin and R. H. J. Grimshaw. Interfacial progressive gravity waves in a two-layer shear flow. Phys. Fluids, 26:1731--1739, 1983. doi:10.1063/1.864372
A rational approximation to the evolution of a free surface during fluid withdrawal through a point sink
No full textThe time varying flow in which fluid is withdrawn from a reservoir through a point sink of variable strength beneath a free surface is considered. Asymptotic techniques are used to derive an approximate solution to the flow that is valid at intermediate times, giving a simple rational approximation to track changes in the free surface for any temporal variations in the sink strength. Comparisons with numerical simulations are given, showing that the approximation has wide applicability
Free surface flows emerging from beneath a semi-infinite plate with constant vorticity
No full textThe free surface flow past a semi-infinite horizontal plate in
a finite-depth fluid is considered. It is assumed that the fluid is
incompressible and inviscid and that the flow approaches a uniform shear
flow downstream. Exact relations are derived using conservation of mass
and momentum for the case where the downstream free surface is flat. The
complete nonlinear problem is solved numerically using a boundary integral
method and these waveless solutions are shown to exist only when the
height of the plate above the bottom is greater than the height of the
uniform shear flow. Interesting results are found for various values of
the constant vorticity. Solutions with downstream surface waves are also
considered, and nonlinear results of this type are compared with linear
results found previously. These solutions can be used to model the flow
near the stern of a (two-dimensional) ship.Faculty of ScienceNo Full Tex
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