Physical Modelling of Flow and Head along with Dead-end and Looped Manifolds

In this study, physical models were designed and fabricated to investigate the hydraulic behaviour of dead-end and looped PVC manifolds. The physical models consisted of a water supply tank with overflow, PVC manifolds, steel supports, collection tank, pump, pressure sensors and valves to allow flow control. Throughout the study, the water level in the supply tank was kept constant. The hydraulic behaviour of dead-end manifolds was investigated using different spacing, S between outlets (S= 3m, S=2.5m, S=2m, S=1.5m, and S=0.75m). The hydraulic behaviour of looped manifolds was investigated using a single outlet spacing of 1.5m. The comparison between the hydraulic behaviour of looped and dead-end manifolds was carried out using the data of the 1.5m outlet spacing. The value of uniformity, U for dead-end and looped manifolds was 82% and 92%, respectively. The value of friction ratio, fn/f1, was found to be 33 and 0.18 for dead-end and looped manifolds, respectively. The experimental data of this study were used to validate selected formulae for estimation of the friction correction factor (G Factor). The results showed that the equation proposed by Alazba et al. (2012) yielded the most satisfactory estimation. The performance of the selected formulae was tested using two statistical indices.

Physical Simulation for the Flow in Straight and Rectangular Loop Manifolds

The flow in a manifolds considered as an advanced problem in hydraulic engineering applications. The objectives of this study are to determine; the uniformity qn/q1 (ratio of the discharge at last outlet, qn to the discharge at first outlet, q1) and total head losses of the flow along straight and rectangular loop manifolds with different flow conditions. The straight pipes were with 18 m and 19 m long and with of 25.4 mm (1.0 in) in diameter each. While, the rectangular close loop configuration was with length of 19 m and with diameter of 25.4 mm (1.0 in) also. Constant head in the supply tank was used and the head is 2.10 m. It is found that outlets spacing and manifold configuration are the main factors affecting the uniformity of flow distribution and friction head losses along manifolds. For large value of outlets spacing, the uniformity coefficient (qn/q1) was found with greatest value of 0.96. Thus, the flow distribution improves with bigger spacing between outlets along manifold. For same manifold length, diameter, inlet head and spacing between outlets (S/L=0.079), the uniformity coefficient was found 0.881 or 88.1% for straight manifold and 0.926 for rectangular loop manifold. From the experimental data, a better uniformity is obtained from the rectangular loop manifold, this is because the friction head loss in rectangular loop manifold was lower than that in straight manifold. The lowest of total head losses was found with greatest outlet spacing along manifold, while the highest of total head losses was found with smallest outlets spacing along manifold. And, the lowest of total head loss was found with the rectangular manifold, while the highest of total head loss was found with the straight manifold.

Use of the Hydraulic Model for the Operational Analysis of the Water Supply Network: A Case Study

This paper presents an analysis of the operation of the water supply system. The analysed network provides water to six small towns. The water supply network covers rural areas of approximately 50 square kilometres with a total of 6130 inhabitants (2020). The area is characterised by relatively large differences in elevation. The water-pipe network supplies water mostly to family housing, public utility buildings, recreational buildings, service and craft entities, religious buildings, and commercial facilities and farms, including breeding farms. The network is supplied from one deep water well and a centrally located water supply tank. A hydraulic model was used for the analysis. The model was developed using the Epanet program, based on numerical and operational data. After validation, selected measurement points were used to calibrate the model. Furthermore, a series of simulations were performed to illustrate the network operation for variable water supply and demand conditions. Single-period analysis was used for modelling due to the type of data obtained. The model allowed for the determination of the head of pressure in the network points and flows in particular sections for the operation parameters studied. The analysis showed that at present, the network is not operating stably. In the case of average demand, water is supplied to all users, but there are areas in the network characterised by high pressure. On the other hand, during maximum water demand, due to the limited water supply to the water reservoir, from which most of the network is supplied, there are water deficiencies that cannot be compensated for by the operating pumping system.

Design and Build a T-Shirt Cannon Firing Mechanism

The work in this paper is a part of the T-shirt cannon automation project. The objective of the project is to develop an autonomous robot carrying cannons to automatically shoot T-shirts during the sports events at the University of Cincinnati (UC). More specifically, the T-shirt cannon will be used and driven by the UC cheerleading team and be able to automatically shoot T-shirts at the audience in the Nippert Stadium and the 5/3 Arena for football and basketball games, respectively. The design and automation of the T-shirt cannon require a significant effort and a multi-disciplinary team to complete. This paper will focus on the process of designing, building, and testing the firing mechanism for the cannon, including the determination of cannon’s firing method, barrel design and assembly, base design and barrel mounting method, pneumatic analysis, and automation and control of the firing of T-shirts. The goal of the firing mechanism is that the cannon would fire off as many T-shirts as possible with the window of a single timeout at the game. The project starts with the preliminary research and the initial testing. During the preliminary research, the relevant safety standards/codes and previous T-shirt cannon designs were reviewed and studied. Especially the possible working with pressurized air, the material used in the design must be rated above the target firing pressure to ensure the cannon itself not explode and the air supply tank and fittings must be in good condition. During the initial testing, the site visits were conducted, the cheerleaders were interviewed, the dimensions of the stadium and the 5/3 arena were measured, and therefore the shooting distance and shooting angles were estimated. After the initial testing and preliminary research, a set of engineering characteristics were established, following by the concept design, in which the barrel assembly, the pneumatics, the firing mechanism, and the mounting method were discussed, analyzed, and determined. The barrels had two major designs, one is using a railing support system with an external tank of air to power and fire the cannon, and another one is using a chamber of air to power and fire the cannon with the barrels surrounding the air chamber itself. Two methods are analyzed and compared. The optimum one, therefore, was determined and developed. For the firing mechanism, two main designs are a spring-loaded firing mechanism that could increase the sealing capabilities of the barrels, and a tight tolerance fit that has less weight. Two designs were tested and analyzed, the optimum one was determined and built, followed by the firing mechanism testing. This paper will describe the process of design, building, and testing the firing mechanisms of this T-shirt cannon at UC. The paper will also discuss the testing results on shooting performance.

Variation of Coefficient of Friction and Friction Head Losses Along a Pipe with Multiple Outlets

The flow in a pipe having multiple outlets is considered as an advanced problem in hydraulic engineering; many discrepancies were found in the literature, in addition to the lack of experimental and field studies. The main goal of this study is to simulate the flow in a pipe with multiple outlets in order to examine the existing methodologies for estimation of the friction head losses, and to propose a methodology that is based on experimental data. The main physical model in this study consisted of a water supply tank, a pipe with multiple outlets having a piezometer at each outlet. Different pipe diameters were used in this study, the pipe diameters were 25.4 mm (1 in), 38.1 mm (1.5 in), 50.8 (2 in) and 76.2 mm (3 in). The inlet heads used were 1.7 m and 2.2 m. The data collected from different flow conditions were used to assess the variation in the coefficient of friction and friction head losses along the pipe length. It can be concluded that the spacing between any two successive outlets (S) and area ratio (AR = Area of outlet/Area of the main pipe) are the main factors affecting the friction head losses along the pipe. The ratio of total friction head losses along a pipe with outlets having the same properties (length (L), discharge (Q), diameter (d) and material) to a pipe without outlets and having the same properties is called the G factor. The G factor calculated using selected formulae was overestimated in comparison to the calculated G factor obtained from experimental data. For large values of S/d (spacing between outlets/diameter of main pipe), the difference between coefficient of friction in first segment (f1) and last segment (fn) of the multiple outlet pipe was noted to be minimal.

Experimental Study for Propane Injection in Gasoline Engines

To study the effect of propane injection on gasoline fueled passenger vehicles fuel economy and cost saving the concept of a modular partial injection system was developed. The injection system was designed with the ability to be fitted in any gasoline fueled vehicle. The Control of the propane injection module was assembled with two stage system of regulators for coarse and fine adjustment of the propane flow to the engine. A digital manometer was used to adjust the pressure across the needle valve. The developed modular system was sealed and housed in a control box mounted to the side of the propane supply tank. The developed system was then fitted in a passenger vehicle and road tested for efficiency and cost savings. In this paper, the design and development criteria in addition to the physical build of the modular propane injection system will be presented. Also, the fuel economy and cost saving from the road test results will be discussed.