Title of dissertation: SEDIMENT SUSPENSION EVENTS FROM RIPPLE BEDS IN OSCILLATORY FLOW: EXPERIMENTS Philip Leland Knowles Doctor of Philosophy, 2009 Dissertation directed by: Associate Professor Kenneth T. Kiger Department of Mechanical Engineering An experimental sediment flume is used to investigate sediment transport mechanics within an oscillatory turbulent boundary layer over a mobile sedi...

A laboratory experiment was carried out to investigate the mixing on a sloping bed caused by a localised ray of internal waves breaking with super-critical frequencies. Previous work has shown that for near critical waves the turbulent boundary layer was confined to a thin region just above the bed. As a result, relatively small overturning turbulent lengthscales were observed. On the other han...

The discrete element method (DEM) is used to study the thermal effects of pebble failure in an ensemble of lithium ceramic spheres. Some pebbles crushing in a large system is unavoidable and this study provides correlations between the extent of pebble failure and the reduction in effective thermal conductivity of the bed. In the model, we homogeneously induced failure and applied nuclear heati...

Surface roughness of laser powder bed fusion (L-PBF) printed overhang regions is a major contributor to deteriorated shape accuracy/surface quality. This study investigates the mechanisms behind evolution surface (Ra) in regions. The morphology result combination border track contour, adhesion, warp deformation, and dross formation, which strongly related angle (?). When 0° ? ? 15°, does not af...

Technology in VLSI industry has improved in accordance with moore’s law , so density of transistor in Integrated Circuit(IC) is increased . Testing this IC with the bed of nail technique becomes very difficult so solution to this was given by IEEE 1149.1 boundary scan standard also called as Joint Test Access Group(JTAG) using which interconnects between the IC mounted on PCB was tested without...

Canul-Chay et al. [1] have conducted the segregation experiment of binary granular mixtures in a bed and subjected the bed to vibration. They report that the reverse Brazil-Nut phenomenon (RBNP) was never observed in their experiments and thus conclude that such does not exist. However, we have clearly demonstrated in [2] by Molecular Dynamics simulations that the reverse Brazil-Nut problem not...

Australia has experienced a sudden and unexpected resurgence in bed bug infestations from both Cimex lectularius L. and Cimex hemipterus F. A survey in 2006 revealed that infestations had increased across the nation by an average of 4,500% since the start of the decade. In response, a multi-disciplinary approach to combat the rise of this public health pest was implemented and involved the coor...

This paper reports the application of a two-dimensional (2D) depth-averaged model to dam break flows over alluvial sand beds with an initial bed step. The model applies the Finite Element Method to discretize the computational domain using an unstructured mesh made of triangular elements. Two downstream boundary conditions were tested: zero (dry) and non-zero (wet) initial water depths. The mod...

The average bed and sidewall shear stresses in smooth rectangular open-channel flows are determined after solving the continuity and momentum equations. The analysis shows that the shear stresses are function of three components: (1) gravitational; (2) secondary flows; and (3) interfacial shear stress. An analytical solution in terms of series expansion is obtained for the case of constant eddy...

The modified log-wake law, which was developed for turbulent boundary layers and pipe flows, is extended to turbulent flows in open-channels. Turbulent velocity profiles in open-channels can be approximated with three components: (1) the law of the wall that results from the constant bed shear stress; (2) the law of the wake that reflects the effects of gravity, secondary currents and bed rough...