Thesis (M.S. in civil engineering)--Washington State University, August 2006. / Includes bibliographical references (p. 33-34).

Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2005. / Word processed copy. Summary in English and Chinese. Includes bibliographical references. Also available online.

Dissertation submitted in compliance with the requirements for Masters Degree in Technology: Electrical Engineering (Light Current), Technikon Natal, 1997. / This report details the findings of work carried out over the course of 1994 and 1995 to determine if it is feasible to use an electrostatic technique for the measurement of mass flow rate of pneumatically conveyed solids. This includes results from tests done on a flow rig and at various power stations. / M

A research project has been carried out to provide BG plc with service life predictions of lithium primary batteries capable of supplying a continuous pulsed power supply to two new electronic domestic gas meters over a desired design life of 11.5 years, in UK weather conditions. The paper study includes investigations of the range of suitable lithium technologies and test methods, and detailed reviews of the discharge processes, polarisation and self-discharge failure modes of the lithium thionyl chloride system. A new multi-channel load test rig and a high resolution measurement system, and software analysis tools were designed and constructed, and some 440 accelerated discharge tests were carried out at different stress levels on 4 cell types. The results provide a unique database of the voltage/temperature/load trends through discharge, and generate a ranking order of performance. Basic statistical analyses have been carried out to quantify the variability of performance trends. A hitherto unreported behaviour pattern is characterised. Qualitative models are postulated to account for deviations from normal behaviour exhibited by two cell types. The analysis suggests that catholyte additives could predispose a system to early failure (due to modification of the crystal structure of the reaction products), and that manufacturing tolerances define the degree of failure. Mathematical models of self-discharge rate for both low and medium rate discharge were developed from laboratory measurements. Meter load profiles were also measured, which together with the self-discharge model enabled prediction of operational energy utilisation rates. A sample of 50 batteries was extracted from customers homes, after operating in the field for periods of up to 2 years, and the battery capacity loss rates were measured by the residual capacity method. A comparison of predicted and actual capacity utilisation rates yielded a discrepancy of approximately 1.28. Analysis implied that the source of the discrepancy could be adduced to an under estimate of the impact of self-discharge, but that a factor of up to six times the predicted value was required. Evidence was provided to show that self-discharge rate under operational stresses could be significantly higher than that under the steady-state laboratory measurement conditions, but that that the amplitude and time constant associated with a selfdischarge peak was unknown and not predictable. Mean service lives of 14 and 10 years for the respective battery types in the two types of meter are predicted, the worst case (probability of 0.13% of the population) being failure within approximately 5.9 years.

M.Tech. (Mechanical Engineering Technology) / This project researched the feasibility of using an existing mitre bend on the main condenser crossover ducting as an on-line flow measuring system. This flow measurement is based on the principle of an elbow type of flow meter. There are no detailed published standards or specifications available for Elbow flow meters. The knowledge of the cooling water flow rate through the individual condensers would allow turbine heat rate calculations to be performed. In addition condenser, cooling tower and cooling water pump performance can be evaluated. An on-line system would also highlight potential problems sooner, thus eliminating costly unplanned shutdowns. The majority of the straight length of condenser cooling water piping is under concrete, thus making access very difficult. The exposed condenser piping geometry is not ideal, with very distorted flow profiles expected, due to bends, valves, reducers, etc. Conventional flow measuring systems can therefore not be used, as ideal flow conditions (profiles) before and after the measuring instrument are required to er.sure the specified accuracy. The mitre bend being part of the piping geometry does not introduce additional head loss to the system and coupled to the low cost factor of an elbow type meter was the principal reason for the choice of this type of measuring system. Part of the innovative aspect of this research is that a conventional elbow is not used but an existing mitre bend is utilised as the fundamental flow measuring device. The Elbow/Bend differential pressure method to measure the condenser cooling water flow rate was investigated in the Flow laboratory at Eskom (Technology Research and Investigations). A geometrically similar mitre bend was purchased and installed onto the 700 mm NB pipeline at the laboratory. The diametrical differential pressure was measured at the 22.5° and 45°axes of the 0.8 D mitre bend. The differential pressure was related to the fluid flow rate, and a calibration constant C was determined. The velocity profiles under the test conditions were verified. A Computational Fluid Dynamics model of the laboratory mitre bend was also produced. The model provided a clearer understanding of the internal flow patterns and the exact pressures on the inside and outside of the bend. The tests that were conducted in the laboratory confirmed the suitability of converting the main condenser crossover ducting mitre bends into an on-line cooling water flow measuring systems.

Seventeen square-edged orifice plates were calibrated to study the effect of varying throat length, both in the absence and in the presence of geometrical similarity, on the coefficient of discharge for pipe Reynolds numbers from 20 to1 10,000. The experiments involved the use of hydraulically smooth pipe in test lines of 1 - inch, 1.5 - inch and 2 - inch nominal I.D., corner pressure taps and Beta ratios (orifice diameter/pipe diameter) of 0.2, 0.4 and 0.6. Six of the plates were built using design criteria recommended by the A.S.M.E. in "Fluid Meters" (1), and with Beta ratios specified at 0.4. Each test line was used with two plates, which were identical except for a variation in throat length within the range of the given design recommendations. A comparison of discharge coefficients as a function of pipe Reynolds number indicated the following: (1) Reynolds numbers 30 - 3,000. Consistent differences of 2-6% were observed in the calibration curves due to the variation in throat length allowed by "Fluid Meters".(1). (2) Reynolds number 3,000 - 10,000. Geometry appeared to be much less important, as all calibration curves tended to coincide. Two further plates, for the 1.5 - inch pipe only, were built using the A.S.M.E. "Power Test Code" (2) as a design reference. They were designed to have respectively the minimum and maximum throat length allowable under the code. The results, when plotted, indicated that in a pipe Reynolds number range of 40 - 1,500, plates built identically except for small differences in throat length, still gave distinguishably different calibration curves. The remaining nine plates were divided into three groups of three plates each, encompassing the three pipe diameters and three Beta ratios. All plates within a group were geometrically similar. The results, for pipe Reynolds numbers from 20 to 2,000, indicated that a total specification of orifice shape gave consistent calibration curves with no apparent absolute size effects. Thus, both "Fluid Meters" *and the "Power Test Code" recommended design criteria for standard orifice plates which do not completely take into account the effect of geometry on the coefficient of discharge at low Reynolds numbers. In particular, the tolerances allowed on throat length are too large. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

No description available.

Although a wide range of flow measurement devices and methods already exist for the measurement of irrigation water, water users and water management officials still claim there is a need for more appropriate devices that are non-intrusive, reliable, easy to install and maintain, and cost effective. Meters that are typically used for irrigation water measurement were tested in a laboratory as an initial part of the research and measurement errors larger than ±10 % of the actual discharge was recorded. This study was aimed at evaluating an experimental measuring method that may meet the requirements of the users. The experimental method is based on the unique relationship between the differential pressure and the discharge of a specific pump. By determining this relationship for a specific pump over a range of operating conditions (but for specific installation conditions), a curve similar to the pump curve as developed by the pump manufacturer can be established. If this relationship is inversed (into a discharge-differential pressure relationship), it can be used to calculate the discharge of the pump by measuring the differential pressure. The volume of water discharged by the pump over a period of time can then be determined by integrating the calculated discharge over time. Laboratory tests were conducted to evaluate the validity of the proposed measuring method. The tests entailed the development of the discharge-differential pressure relationship for the specific pump being used, by simultaneously measuring the system discharge, and pressure at both the suction and delivery sides of the pump. Once the relationship had been developed, a set of independent tests was conducted and the pressure measurements used to calculate the discharge through the system. The calculated discharge values were then compared with the measured values. The experimental measuring method was also evaluated in the field through empirical testing of its application in the field. The necessary equipment was installed and calibrated at an irrigation system pump station at the Orange-Riet Water User Association, and data collected over a two week period. The laboratory evaluation of the proposed measurement method produced favourable results, with the analyses showing that discharge can be "measured" with this method at errors smaller than ± 5.4 % of the reference reading within a specified range of flow rates, which is better than the errors produced by the conventional meters evaluated during the initial part of the research. The field tests showed that the method can be applied successfully to monitor pump abstractions. The method's results were compared to two reference measurements and it was found that the volume of water abstracted according to the experimental method was within ± 2.6 % of the reference measurements. The field work also showed that from a practical application point of view, the method has definite advantages over the conventional meters, although it is not less expensive than other measuring devices. The advantages include easier installation, high turn-down ratios, low maintenance requirements, no additional head loss, and suitable for telemetric data collection. Further work that is required include investigations on the use of a differential pressure transducer (rather than two separate suction and delivery side transducers), since this may reduce costs and the number of recorded data points, as well as evaluations of the validity of the discharge - differential pressure relationship over a long period of time, since it may change due to wear on the pump or motor. / Dissertation (M Eng (Agricultural Engineering))--University of Pretoria, 2005. / Civil Engineering / unrestricted

No description available.

No description available.