Applied Mechanics Commons^™

Unsteady Flow Simulations About Moving Boundary Configurations Using Dynamic Domain Decomposition Techniques, Guan-Wei Yen

Mechanical & Aerospace Engineering Theses & Dissertations

A computational method is developed to solve the coupled governing equations of an unsteady flowfield and those of rigid-body dynamics in six degrees-of-freedom (6-DOF). This method is capable of simulating the unsteady flowfields around multiple component configurations with at least one of the components in relative motion with respect to the others. Two of the important phenomena that such analyses can help us to understand are the unsteady aerodynamic interference and the boundary-induced component of such a flowfield. By hybridizing two dynamic domain decomposition techniques, the grid generation task is simplified, the computer memory requirement is reduced, and the governing …

Soil Sampling Made Easier, Mike Bolland, Mike Baker

Journal of the Department of Agriculture, Western Australia, Series 4

A new rotary blade soil sampler has taken the hard work out of collecting soil samples from Western Australia's hard-setting soils to test for soil phosphorus levels .

Conceived and developed by Department of Agriculture technical officer Mike Baker, it should enable soil testing to be more widely adopted. Fortunately, the soil calibration tests that were developed using pogo samples can also be used for the new sampler.

Stubble : Friend And Foe, Department Of Agriculture And Food, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

Several articles in this issue of the Journal of Agriculture discuss some of the important issues of stubble management. The articles are condensed from some of the papers presented at a stubble workshop at Geraldton in 1991.

On Shock Capturing For Liquid And Gas Media, Tze Jang Chen

Mathematics & Statistics Theses & Dissertations

The numerical investigation of shock phenomena in gas or liquid media where a specifying relation for internal energy is absent poses special problems. Classically, for gas dynamics the usual procedure is to employ a splitting scheme to remove the source terms from the Euler equations, then up-wind biased shock capturing algorithms are built around the Riemann problem for the system which remains. However, in the case where the Euler equations are formulated in the term of total enthalpy, a technical difficulty associated with equation splitting forces a pressure time derivative to be treated as a source term. This makes it …

Numerical Investigation Of A Non-Newtonian Material Through A Sudden Pipe Expansion, V. G. Masanja

Tanzania Journal of Engineering and Technology (TJET)

A numerical method for solving two dimensional elliptic boundary-value problems of fourth order is used for finding stationary solutions of the equations of motion for a laminar flow through a sudden pipe expansion of an incompressible non-Newtonian fluid with a constitutive equation of the Reiner-Rivlin (R-R) type. Results for the Newtonian fluid, which is a special case, are in excellent agreement with those by previous investigators and they demonstrate the reliability, superiority and accuracy of the method. Results for the non-Newtonian cases could be of value for fixing ideas about visco-elastic behaviour although the R-R fluid allows only inelasticity: this …

Application Of Shape Sensitivity Analysis For Computation Of Transient Free-Surface Flows, Frank Nicolas Michel

Mechanical & Aerospace Engineering Theses & Dissertations

Shape sensitivity analysis is introduced into a numerical scheme simulating a transient free-surface flow and applied to the case of a fluid advancing through a bed of cylinders. For this incompressible Newtonian flow, viscous forces are dominant. A penalty function finite element formulation is used to solve the problem. Coordinates of nodes on the moving boundary are chosen as design variables and an analytical formulation of the gradient of the finite element algebraic system, with respect to these variables, is derived.

In a numerical example, the results obtained with and without sensitivity analysis are compared. The efficiency and accuracy of …

The Development Of An Efficient Lupin Harvesting Front, E D. Blanchard

Journal of the Department of Agriculture, Western Australia, Series 4

Harvest losses represent a significant reduction in lupin production and farm productivity.

Since 1984, the Department's Farm Machinery Research and Liaison Unit at the Dryland Research Institute has studied the lupin harvesting operation to improve its mechanical efficiency. An experimental and a prototype harvesting front were built and tested in the field. Guidlines for efficient lupin harvesting were produced, and commercial modifications developed.

Improved Fertilizing Practices On The Peel-Harvey Catchment, P T. Arkell

Journal of the Department of Agriculture, Western Australia, Series 4

Broad-acre farmers in the Peel-Harvey catchment have met a challange and achieved a great deal since the fertilizer extension programme started in 1983.

The main objective of the extension programme has been to ensure that every year three-quarters of the farmers make economically and technically sound fertilizer decisions, thus causing a minimum amount of phosphorus to enter the waterways of the Peel-Harvey estuarine system.

An Apparatus For Measuring The Thermal Conductivity Of Cast Insulation Materials, Christine A. Wilkins, Robert L. Ash

Mechanical & Aerospace Engineering Faculty Publications

A steady-state apparatus has been developed for measuring the thermal conductivity of cast materials. The design has employed a novel thermal symmetry arrangement which can permit total electrical isolation of the test material from its surroundings. © 1980 American Institute of Physics

There's Little To Choose Between Scarifier Points, C R. Lester

Journal of the Department of Agriculture, Western Australia, Series 4

Tests on scarifier points showed that methods of treating them to prolong their life had little effect.

Effect Of Compliant Wall Motion On Turbulent Boundary Layers, Dennis M. Bushness, Jerry N. Hefner, Robert L. Ash

Mechanical & Aerospace Engineering Faculty Publications

A critical analysis of available compliant wall data which indicated drag reduction under turbulent boundary layers is presented. Detailed structural dynamic calculations suggest that the surfaces responded in a resonant, rather than a compliant, manner. Alternate explanations are given for drag reductions observed in two classes of experiments: (1) flexible pipe flows and (2) water-backed membranes in air. Analysis indicates that the wall motion for the remaining data is typified by short wavelengths in agreement with the requirements of a possible compliant wall drag reduction mechanism recently suggested by Langley. Copyright © 1977 American Institute of Physics.

Opposed Disc Plough Furrows Hard Kimberley Soils, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

THE work of reclaiming the eroded areas of the Ord River catchment has posed special problems for field staff of the Department of Agriculture engaged on this large scale project.

Thousands of miles of furrows must be contour-ploughed and seeded in extremely hard ground over big areas of eroded country.

A Practical Guide To Building Contour Banks With A Road Grader, J E. Watson

Journal of the Department of Agriculture, Western Australia, Series 4

THOUSANDS of miles of contour banks have been built in Western Australia, and most of this earthmoving has been done by tractor and disc plough* or by road grader.

This article describes the technique recommended for bank construction with the road grader.

Water Conservation On The Farm, John W. Lewis

Journal of the Department of Agriculture, Western Australia, Series 4

SMALL scale conservation of water for agricultural use is becoming increasingly important throughout Australia.

As land development intensifies, it is natural that farmers turn to more dams and earthen tanks for stock water and irrigation.

Adequate water is essential to supply the carrying capacities made possible by improved pastures, and where greater quantities of water can be stored, fodder crops, pastures, orchards and vegetables can be irrigated.

Automatic Waterers For Day Old Chickens, P Smetana, W. Ward

Journal of the Department of Agriculture, Western Australia, Series 4

ONE of the most tedious and time consuming tasks on a poultry farm is the provision of water to chicks from day old up to the age of three or four weeks.

Most poultry farmers use half-gallon glass fonts with metal bases for the first few weeks, until the chicks are old enough to use the automatic watering system usually situated along one wall of the brooder house.

This cumbersome glass font system can be replaced by the cheap and easily installed automatic watering system described below. This system has already been adopted by several local poultry farmers.

A Useful Farm-Made Roller, V E. Western

Journal of the Department of Agriculture, Western Australia, Series 4

A very serviceable compacting roller can be constructed at little expense by using discarded truck tyres.

The roller described here has an overall width of 5 ft. 3 in. and carries seven 9.00 x 24 semi-trailer tyres which had been discarded when the treads were worn smooth.