A large proportion of water and wastewater systems have traditionally been analyzed and designed without the consideration of the nature, risk, and potential consequence of hydraulic transients. Recent advancements in numerical hydraulic modeling have spawned a specialty hydraulic field based on numerical transient analysis. The current practice within this field often lacks physical understanding and can be misguided by both the current knowledge, technology based limitations, and by the sole reliance on numerical models. This thesis aims to provide insights into some of the shortcomings of current practice and to develop the importance and application of field data based confirmations. The thesis examines the advances in the current field oriented technology for recording transient pressures, and provides examples and insights on how this data can be used both in conjunction with numerical modeling and on its own as a first step to a proposed frequency based transient risk assessment methodology. The thesis establishes definitions and a preliminary methodology for a Transient Risk Index.

Analytical and experimental laboratory studies were conducted for rapid pressurizing of entrapped gas at the end of a horizontal liquid pipeline. In this paper analytical and experimental model study are presented for pressurizing entrapped gas pocket at the end of a liquid column in a horizontal pipeline. Analytical models are considered such as (1) acoustic effect of both liquid and gas side, (2) variation of liquid length, and (3) thermal damping process. Closed form of solutions were derived for a lumped liquid and lumped gas model if pipeline is a horizontal. Experiments were conducted to verify the analytical models. Comparison of analytical and experimental model results were presented. Analytical model was developed to define the physics behind the gas venting case. Experiments were conducted for a range of orifice sizes from 1/16 to of the pipe diameter with reservoir pressure two, three and four times of ambient pressure for five different pipe configurations. Experimental results confirm the assumption of modified entrapped air model is correct.

Thesis--M. Sc.(Eng.)--University of Hong Kong. / Mimeographed.

Thesis--M. Sc. (Eng.), University of Hong Kong. / Mimeographed.

published_or_final_version / Physics / Master / Master of Philosophy

No description available.

No description available.

When assessing the quality of a brass instrument the player must consider a number of factors, the main consideration being the playability of the chosen instrument. The playability of an instrument is a broad term used to describe how well the instrument plays; this includes how in tune the resonant modes are, how easy it is to start and move between notes, how easy it is to bend notes and the degree of spectral enrichment during a crescendo that is able to be produced. The starting transient is known to be of crucial importance for both the musician and listener, and previous work in the field has been mainly concerned with such starting transients; this work focusses on inter-note transitions. Transitions between notes include both starting and finishing transients as the initial note is ended and the next begun. Using high speed photography images synchronised with pressure signals from the mouthpiece and bell end, the internote transitions are explored. Results from these experiments are compared with those from a simple one dimensional time domain model. Other techniques used to determine the playability of a specific instrument include the rate at which the instrument timbre becomes `brassy' due to nonlinear effects, that are a consequence of loud playing. The relative significance of viscothermal wall losses and nonlinear effects within realistic brass instruments have been explored here using experiments on cylindrical tubes of different internal diameters. These experimental results are compared with results from a computational model that uses weakly nonlinear wave propagation theory and includes viscothermal losses. It is also possible on some brass instruments, when playing loudly, to achieve what are known as super high notes; these notes are above the frequency where the instrument has well defined resonances. Experimental results are presented here using optical techniques to visualise the motion of the player's lips during playing of these super high notes.

Thesis (Ph.D.)--University of Tulsa, 1984. / Bibliography: leaves 73-75.

Thesis (M.P.H.)--University of Michigan, 1947.