scholarly journals Roman Hydraulic Engineering: The Pont du Gard Aqueduct and Nemausus (Nîmes) Castellum

Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 54
Author(s):  
Charles R. Ortloff
Keyword(s):  
Flow Rate ◽  
Distribution System ◽  
Water Distribution ◽  
Flow Distribution ◽  
Maximum Flow ◽  
Hydraulic Engineering ◽  
Fine Tuning ◽  
Engineering Practice ◽  
Engineering Technology ◽  
Wall Flow

The water distribution castellum at the terminal end of the Pont du Gard aqueduct serving the Roman city of Nemausus in southern France is analyzed for its water engineering design and operation. By the use of modern hydraulic engineering analysis methods applied to analyze the castellum, new aspects of Roman water engineering technology are discovered not previously reported in the archaeological literature. Analysis of the castellum’s 10 basin wall flow distribution pipelines reveals that when a Roman version of modern critical flow theory is utilized in their design, the 10 pipelines optimally transfer water to city precincts at the maximum flow rate possible with a total flow rate closely approximating the input flow rate from the aqueduct. The castellum’s three drainage floor ports serve as additional fine-tuning to precisely match the input aqueduct flow rate to the optimized 10 pipeline output flow rate. The castellum’s many hydraulic engineering features provide a combination of advanced water engineering technology to optimize the performance of the water distribution system while at the same time enhancing the castellum’s aesthetic water display features typical of Roman values. While extensive descriptive archaeological literature exists on Roman achievements related to their water systems both in Rome and its provinces, what is missing is the preliminary engineering knowledge base that underlies many of their water system’s designs. The present paper is designed to provide this missing link by utilizing modern hydraulic engineering methodologies to uncover the basis of Roman civil engineering practice—albeit in Roman formats yet to be discovered.

Research on an axial-mounted dual magnetostrictive material rods-based electro-hydrostatic actuator

2021 ◽  
pp. 1045389X2110145
Author(s):  
Yuchuan Zhu ◽  
Chang Liu ◽  
Yunze Song ◽  
Long Chen ◽  
Yulei Jiang ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Flow Rate ◽  
Flow Distribution ◽  
Maximum Flow ◽  
Magnetostrictive Material ◽  
Simulation Techniques ◽  
Motion State ◽  
New Type ◽  
Output Characteristics ◽  
Active Rectification

In this paper, an electro-hydrostatic actuator driven by dual axial-mounted magnetostrictive material rods-based pumps (MMPs) with a new type of active rectification valve is designed in the current study. Based on flow distribution of the active rectification valve and driving energy provided by two MMPs, the actuator can output continuous and bidirectional displacement. By establishing a mathematical model of the actuating system, using simulation techniques, the change rule of hydraulic cylinder’s motion state caused by different driving signals are studied and analyzed. Test equipment platform is constructed in the laboratory to test the output characteristics and confirm the feasibility of the new concept. The experimental results indicate that the maximum flow rate can reach approximately 2.7 L·min−1, while the operating frequency is 180 Hz.

The Water Supply and Distribution System of the Nabataean City of Petra (Jordan), 300 bc– ad 300

2005 ◽  
Vol 15 (1) ◽  
pp. 93-109 ◽  
Author(s):  
Charles R. Ortloff
Keyword(s):  
Water Resources ◽  
Water Supply ◽  
Distribution System ◽  
Water Distribution ◽  
Maximum Flow ◽  
Living Standard ◽  
City Development ◽  
Trade Networks ◽  
Supply And Distribution ◽  
Design Function

The water supply and distribution system of the Nabataean city of Petra in southwestern Jordan has been explored and mapped. Analysis of the system indicates exploitation of all possible water resources using management techniques that balance reservoir storage capacity with continuous flow pipeline systems to maintain a constant water supply throughout the year. Nabataean Petra was founded c. 300 bc; urban development progressed with later Roman administration of the city starting at ad 106; Byzantine occupation continued to the seventh century ad. Trade networks that extended throughout much of the ancient Near East and Mediterranean world intersected at Petra, and brought not only strategic and economic prominence, but also impetus to develop water resources fully to sustain demands of increasing population and city elaboration. City development was influenced by artistic, cultural and technological borrowings from Seleucid, Syro-Phoenician, Greek and Roman civilizations; the Petra water-distribution system included hydraulic technologies derived from these contacts as well as original technical innovations that helped to maintain the high living standard of city dwellers throughout the centuries. Analysis of the Nabataean water network indicates design criteria that promote stable flows and use sequential particle-settling basins to purify potable water supplies. They also promote open channel flows within piping at critical (maximum) flow rates that avoid leakage associated with pressurized systems and have the design function to match the spring supply rate to the maximum carrying capacity of a pipeline. This demonstration of engineering capability indicates a high degree of cognitive skill in solving complex hydraulic problems to ensure a stable water supply and may be posited as a key reason behind the many centuries of flourishing city life.

scholarly journals Hydraulic Engineering at 100 BC-AD 300 Nabataean Petra (Jordan)

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3498
Author(s):  
Charles R. Ortloff
Keyword(s):  
Water Supply ◽  
Flow Rate ◽  
Distribution Systems ◽  
Maximum Flow ◽  
Hydraulic Engineering ◽  
World Heritage Site ◽  
Maximum Flow Rate ◽  
Pipeline System ◽  
Supply And Distribution ◽  
Pipeline Systems

The principal water supply and distribution systems of the World Heritage site of Petra in Jordan were analyzed to bring forward water engineering details not previously known in the archaeological literature. The three main water supply pipeline systems sourced by springs and reservoirs (the Siq, Ain Braq, and Wadi Mataha pipeline systems) were analyzed for their different pipeline design philosophies that reflect different geophysical landscape challenges to provide water supplies to different parts of urban Petra. The Siq pipeline system’s unique technical design reflects use of partial flow in consecutives sections of the main pipeline to support partial critical flow in each section that reduce pipeline leakage and produce the maximum flow rate the Siq pipeline can transport. An Ain Braq pipeline branch demonstrated a new hydraulic engineering discovery not previously reported in the literature in the form of an offshoot pipeline segment leading to a water collection basin adjacent to and connected to the main water supply line. This design eliminates upstream water surges arising from downstream flow instabilities in the two steep pipelines leading to a residential sector of Petra. The Wadi Mataha pipeline system is constructed at the critical angle to support the maximum flow rate from a reservoir. The analyses presented for these water supply and distribution systems brought forward aspects of the Petra urban water supply system not previously known, revising our understanding of Nabataean water engineers’ engineering knowledge.

scholarly journals Dynamic hydraulic models to study sedimentation in drinking water networks in detail

2012 ◽  
Vol 5 (1) ◽  
pp. 121-137
Author(s):  
I. W. M. Pothof ◽  
E. J. M. Blokker
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Water Distribution ◽  
Flow Direction ◽  
Maximum Velocity ◽  
Flow Distribution ◽  
Necessary Condition ◽  
Daily Maximum ◽  
Shear Stresses ◽  
Water Networks

Abstract. Sedimentation in drinking water networks can lead to discolouration complaints. A sufficient criterion to prevent sedimentation in drinking water networks is a daily maximum velocity of 0.25 m s−1. Flushing experiments have shown that this criterion is a sufficient condition for a clean network, but not a necessary condition. Drinking water networks include many locations with a maximum velocity well below 0.25 m s−1 without sediment. Other criteria need to be developed to predict which locations are susceptible to sedimentation and to prevent sedimentation in future networks. More distinctive criteria are helpful to prioritise flushing operations and to prevent water quality complaints. The authors use three different numerical modelling approaches – quasi-steady, rigid column and water hammer – with a temporal discretisation of 1 s in order to assess the influence of unsteady flows on the wall shear stress, causing resuspension of sediment particles. The model predictions are combined with results from flushing experiments in the drinking water distribution system of Purmerend, the Netherlands. The waterhammer model does not result in essentially different flow distribution patterns, compared to the rigid column and quasi-steady modelling approach. The extra information from the waterhammer model is a velocity oscillation of approximately 0.02 m s−1 around the quasi-steady solution. The presence of stagnation zones and multiple flow direction reversals seem to be interesting new parameters to predict sediment accumulation, which are consistent with the observed turbidity data and theoretical considerations on critical shear stresses.

Water Flow Distribution in Horizontal Protruding-Type Header Contaminated With Bubbles

1999 ◽  
Author(s):  
Sachiyo Horiki ◽  
Masahiro Osakabe
Keyword(s):  
Uniform Distribution ◽  
Gas Phase ◽  
Water Flow ◽  
Flow Rate ◽  
Water Distribution ◽  
Air Flow ◽  
Water Flow Rate ◽  
Flow Distribution ◽  
Air Flow Rate ◽  
Distribution Behavior

Abstract Flow header for small multiple pipes is commonly used in boilers and heat exchangers. The system contributes to raise the heat transfer efficiency in the components. The flow distribution mechanism of the header for water has been studied and the calculation procedure for the design has been recommended for a single-phase condition. It is also recommended to avoid the bubbles in the header to obtain a uniform water flow rate to each small pipe. But in some cases, the header has to be used to distribute a flow containing bubbles. Distribution behavior of water with a gas-phase was studied experimentally in a horizontal header with four vertical pipes. In the present experimental header, it was possible to protrude the branch pipes inside of the header and the effect of protruding length on the water distribution behavior was studied. When the protruding length was 0, the water distribution rate to the first pipe rapidly increased and the rates to the others decreased with a small amount of bubbles. As the bubbles in the header were absorbed only into the first pipe, the average two-phase density in the first pipe decreased. The decreased pressure head promotes the rush of water into the first pipe such as in an airlift pump. By increasing the air flow rate in the header inlet further, the flow rate to the first pipe took a maximum and then tended to decrease. The increased air flow rate in the first pipe increased the pressure loss in the pipe and resulted in a reduction in the water flow rate. The more important and serious behavior could be seen in the other pipes where the water flow rate decreased to 1/5 of the uniform distribution rate. By increasing the protruding length, the non-uniform distribution of water was suppressed because the gas-phase entered not only the first pipe but also the others. The best result was obtained when the four branch pipes were protruded into the center of header.

scholarly journals DNA Printing Integrated Multiplexer Driver Microelectronic Mechanical System Head (IDMH) and Microfluidic Flow Estimation

Micromachines ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 25
Author(s):  
Jian-Chiun Liou ◽  
Chih-Wei Peng ◽  
Philippe Basset ◽  
Zhen-Xi Chen
Keyword(s):  
Mechanical System ◽  
Flow Rate ◽  
Pulse Width ◽  
Flow Distribution ◽  
Internal Flow ◽  
Maximum Flow ◽  
Maximum Flow Rate ◽  
Driving Voltage ◽  
Generation Process ◽  
Injection Nozzle

The system designed in this study involves a three-dimensional (3D) microelectronic mechanical system chip structure using DNA printing technology. We employed diverse diameters and cavity thickness for the heater. DNA beads were placed in this rapid array, and the spray flow rate was assessed. Because DNA cannot be obtained easily, rapidly deploying DNA while estimating the total amount of DNA being sprayed is imperative. DNA printings were collected in a multiplexer driver microelectronic mechanical system head, and microflow estimation was conducted. Flow-3D was used to simulate the internal flow field and flow distribution of the 3D spray room. The simulation was used to calculate the time and pressure required to generate heat bubbles as well as the corresponding mean outlet speed of the fluid. The “outlet speed status” function in Flow-3D was used as a power source for simulating the ejection of fluid by the chip nozzle. The actual chip generation process was measured, and the starting voltage curve was analyzed. Finally, experiments on flow rate were conducted, and the results were discussed. The density of the injection nozzle was 50, the size of the heater was 105 μm × 105 μm, and the size of the injection nozzle hole was 80 μm. The maximum flow rate was limited to approximately 3.5 cc. The maximum flow rate per minute required a power between 3.5 W and 4.5 W. The number of injection nozzles was multiplied by 100. On chips with enlarged injection nozzle density, experiments were conducted under a fixed driving voltage of 25 V. The flow curve obtained from various pulse widths and operating frequencies was observed. The operating frequency was 2 KHz, and the pulse width was 4 μs. At a pulse width of 5 μs and within the power range of 4.3–5.7 W, the monomer was injected at a flow rate of 5.5 cc/min. The results of this study may be applied to estimate the flow rate and the total amount of the ejection liquid of a DNA liquid.

scholarly journals Secured Domestic Water Monitoring and Distribution System

2020 ◽  
Vol 9 (5) ◽  
pp. 2327-2330
Keyword(s):  
Flow Rate ◽  
Distribution System ◽  
Water Distribution ◽  
Vital Role ◽  
Water Monitoring ◽  
Domestic Water ◽  
Flow Monitoring ◽  
Prevention System ◽  
Valve Position ◽  
Distribution Station

Excess usage of water than it is actually needed and water theft are the major issues leading to water scarcity nowadays. Some people draw more water by using motor pump. Whenever they use motor pump, or they open the valve to the maximum, the flow rate will be increased. Hence in the proposed system, measurement of flow rate plays a vital role. Water monitoring and theft prevention system are employed which records the flow rate and thereby providing notification about the theft and excess usage of water. In the proposed system, each consumer end is provided with a water flow monitoring system which consists of a flow sensor to measure the flow rate and an arduino controller for recording the flow rate. The flow rate value will be sent to the water distribution station using GSM. The flow rate is fixed by the central water distribution station, so that each consumer end will be receiving an equal quantity of water. Solenoid valve is attached in the Pipeline so that the flow rate can be varied by adjusting the valve position. The valve position, time of supply and the flow rate will be controlled by the central water distribution system. The GSM MODEM is initiated by the ON/OFF switch which is controlled by the arduino.

The Ancient Middle East

2009 ◽  
Author(s):  
Charles R. Ortloff
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Maximum Flow ◽  
Living Standard ◽  
City Development ◽  
City Life ◽  
City Water ◽  
Piping Networks ◽  
The Many ◽  
The City

The origins of Nabataean Petra began c. 300 BCE from nomadic settlement origins and extended to later Roman administration of the city at 106 CE with final Byzantine occupation (Basile 2000) to the 7th century CE. Trade networks that extended throughout much of the ancient orient and Mediterranean world intersected at Petra and brought not only strategic and economic prominence but also the impetus to develop water resources to sustain increasing population and city elaboration demands. City development was influenced by architectural, cultural, and technological borrowings from Seleucid, Syro-Phoenician, Greek, Roman, and Far Eastern civilizations. The city water distribution system utilized many hydraulic technologies derived from these contacts that together with original technical innovations helped to maintain a high living standard throughout the centuries. Analysis of Nabataean piping networks indicates that design criteria were employed that promoted stable flows within piping, employed sequential particle settling basins to purify potable water supplies, promoted open-channel flow within piping at critical (maximum) flow rates that avoided leakage associated with pressurized systems, and matched spring supply rates to the maximum carrying capacity of pipelines. This demonstration of engineering capability indicated a high degree of skill in solving complex hydraulics problems to ensure a stable water supply and is a key reason behind the many centuries of flourishing city life. Because of Petra’s location between Egyptian, Babylonian, and Assyrian territories, many exterior influences dominated the Nabataean cultural landscape over time. The sacred spring created by Moses, as described in Exodus accounts, has been equated with the Ain Mousa spring outside of Petra although controversy exists as to its location (and historical accuracy) with contending Sinai sites. Biblical and Koranic references to areas around Petra relate to the use of water channels and springs by the inhabitants to maintain agriculture and settlements; Assyrian texts ascribed to the Sargonic era (715 BCE) mention tent cities in this area. The earliest proto-Nabataean period (6th century BCE) is derived from Edomite agriculturalists assimilating with nomadic tribal groups familiar with caravan-based trade activities. Although the origins of the Nabataeans remain controversial (Gleuck 1959, 1965; Taylor 2001; Guzzo and Schneider 2002), their final consolidation in areas around Petra in the early 3rd century BCE is evident from the archaeological record.

scholarly journals Dynamical stability of water distribution networks

2019 ◽  
Vol 475 (2230) ◽  
pp. 20190291 ◽  
Author(s):  
Naoki Masuda ◽  
Fanlin Meng
Keyword(s):  
Nonlinear Dynamics ◽  
Flow Rate ◽  
Distribution System ◽  
Water Distribution ◽  
Nonlinear Dynamical System ◽  
Distribution Networks ◽  
Analytical Framework ◽  
Water Distribution Networks ◽  
Pipe Network ◽  
Nonlinear Dynamical

Water distribution networks are hydraulic infrastructures that aim to meet water demands at their various nodes. Water flows through pipes in the network create nonlinear dynamics on networks. A desirable feature of water distribution networks is high resistance to failures and other shocks to the system. Such threats would at least transiently change the flow rate in various pipes, potentially undermining the functionality of the whole water distribution system. Here we carry out a linear stability analysis for a nonlinear dynamical system representing the flow rate through pipes that are interconnected through an arbitrary pipe network with reservoirs and consumer nodes. We show that the steady state is always locally stable and develop a method to calculate the eigenvalue that corresponds to the mode that decays the most slowly towards the equilibrium, which we use as an index for resilience of the system. We show that the proposed index is positively correlated with the recovery rate of the pipe network, which was derived from a realistic and industrially popular simulator. The present analytical framework is expected to be useful for deploying tools from nonlinear dynamics and network analysis in the design, resilience management and scenario testing of water distribution networks.

Studies on Sprinklers Arrangement in Sprinkler Systems

2013 ◽  
Vol 457-458 ◽  
pp. 1686-1690
Author(s):  
Fan Lin Cui ◽  
Fang Qu ◽  
Yong Yi Cui ◽  
Lei Mai
Keyword(s):  
Flow Rate ◽  
Water Distribution ◽  
Distribution Curve ◽  
Surface Fitting ◽  
Engineering Practice ◽  
Working Pressure ◽  
Sprinkler Systems ◽  
3D Surface ◽  
Function Expression ◽  
Efficiency And Reliability

To improve the fire suppressing efficiency and reliability of the sprinkler systems, in this paper we analysis and discuss a problem about sprinklers arrangement. Use the water distribution curve of ZST-15 and the MATLAB to accomplish a 3D surface fitting among radius of protection, working pressure and mounting height as well as get a function expression about them. After that, aiming at the problems happened in engineering practice, we propose a method of determine the sprinklers arrangement distance and their mounting height, in addition give suggestions about choosing fire pools and work out the flow rate of sprinkler systems through calculation as well.

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