Smart Automated Water Sprinkler (SAWS): Residential irrigation by boundary mapping and variable water pressure control

This study is devoted to determining the long-term strength of porous geomaterials under alternate wetting and drying condition by statical shakedown analysis. In the framework of micromechanics of porous materials, Gurson’s hollow sphere model with Drucker-Prager solid matrix is adopted as the representative volume element. The effects of alternate wetting and drying are considered as variable water pressure imposed on the inner boundary surface of the unit cell. The cyclic responses are separated as a pure hydrostatic part under compressive/tensive loads and an additional deviatoric part to capture shear effects. The reduction of the long-term strength due to inner water pressure is observed by the illustration of obtained macroscopic criteria with respect to various load parameters. In addition, the accuracy of the analytical solution is also verified by comparing to the results of FEM-based step-by-step computations.

Download Full-text

Microturbines at Drinking Water Tanks Fed by Gravity Pipelines: A Method and Excel Tool for Maximizing Annual Energy Generation Based on Historical Tank Outflow Data

Water ◽

10.3390/w11071403 ◽

2019 ◽

Vol 11 (7) ◽

pp. 1403

Author(s):

Thomas John Voltz ◽

Thomas Grischek

Keyword(s):

Water Pressure ◽

Control Valve ◽

Electrical Energy ◽

Energy Generation ◽

Pressure Control ◽

Design Flow ◽

Alternative Methods ◽

Class 1 ◽

Pressure Control Valve ◽

Water Tanks

Wherever the flow of water in a gravity pipeline is regulated by a pressure control valve, hydraulic energy in the form of water pressure can instead be converted into useful mechanical and electrical energy via a turbine. Two classes of potential turbine sites exist—those with (class 1, “buffered”) and those without (class 2, “non-buffered”) a storage tank that decouples inflow from outflow, allowing the inflow regime to be modified to better suit turbine operation. A new method and Excel tool (freely downloadable, at no cost) were developed for determining the optimal hydraulic parameters of a turbine at class 1 sites that maximize annual energy generation. The method assumes a single microturbine with a narrow operating range and determines the optimal design flow rate based on the characteristic site curve and a historical time series of outflow data from the tank, simulating tank operation with a numerical model as it creates a new inflow regime. While no direct alternative methods could be found in the scientific literature or on the internet, three hypothetically applicable methods were gleaned from the German guidelines (published by the German Technical and Scientific Association for Gas and Water (DVGW)) and used as a basis of comparison. The tool and alternative methods were tested for nine sites in Germany.

Download Full-text

Study on Pressure Control for Water Supply System by Fuzzy PID

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.753-755.2628 ◽

2013 ◽

Vol 753-755 ◽

pp. 2628-2631

Author(s):

Jin Hua Wang ◽

Hong Yan Zhang ◽

Jing Xia Niu

Keyword(s):

Water Supply ◽

Water Pressure ◽

Pressure Control ◽

Supply System ◽

Water Supply System ◽

Effective Control ◽

System Response ◽

Fuzzy Pid ◽

Long Time ◽

Pressure Water

This paper show a parameter self-adaptive fuzzy PID controller which was designed by using fuzzy logical rules, and the rules aiming at characteristics of constant pressure water-supply system such as nonlinear, multi-parameters and long time delay. The controller can online auto tuning PID parameters to select the appropriate control parameters, depending on the working conditions for effective control of the water supply system water pressure regulator. The simulation results show that the control system response quick, over regulation measurement and transitional time is greatly reduced, oscillation time shorten, and the system has strong robustness and good stability.

Download Full-text

Fatigue Damage at the Root of the Gate Lip of the Water Gate Under Variable Water Pressure Due to Tide and Ocean Wave

Volume 3: Safety and Reliability; Materials Technology; Douglas Faulkner Symposium on Reliability and Ultimate Strength of Marine Structures ◽

10.1115/omae2006-92129 ◽

2006 ◽

Author(s):

Keitaro Konuma ◽

Masahiro Toyosada ◽

Koji Gotoh

Keyword(s):

Numerical Simulation ◽

Fatigue Crack ◽

Water Level ◽

Crack Growth ◽

Sea Water ◽

Water Pressure ◽

Ground Surface ◽

Simulation Code ◽

Water Gate ◽

Variable Water

The steel water gate, which received variable water pressure due to gap of water level between sea and balancing reservoir, damaged in its gate lip by fatigue crack. In order to find the cause of this damage, various investigate programs, including observation with microscope and measurement of stress and water level, were performed. By the comprehensive analysis of the results of these investigation programs, it was concluded that this damage was caused by the cyclic loading on the gate lip from the ground surface, and found out the relation between sea water level and stress occur at damaged point. After then, the damaged part was replaced with new reinforced element. In addition, for checking the effect of this measure, the crack growth estimation was executed with FLARP, the numerical simulation code which was developed by the authors. As the result of the numerical simulation, the crack growth curve became visible quantitatively, and it was confirmed that the possibility of the reoccurrence of the fatigue crack was removed by the measures which we took, under the assumed loading condition.

Download Full-text

Research on the Permeability of Concrete under the High Water Pressure

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.838-841.1797 ◽

2013 ◽

Vol 838-841 ◽

pp. 1797-1800

Author(s):

Bing Hua Zhao ◽

Shi Ping Zhang

Keyword(s):

Water Pressure ◽

Laboratory Data ◽

Influence Factors ◽

High Water ◽

Software Simulation ◽

Water Head ◽

Concrete Permeability ◽

Practical Engineering ◽

Variable Water ◽

Permeability Structure

Seepage is important influence factors of degradation and instability to the water or under water concrete structure, it is also the difficult point in geotechnical engineering research.Through the concrete seepage experiment，combined with the Seep/W module of GeoStudio software，simulation of unsteady seepage of concrete，it was obtained that the seepage field under the action of a variable water head in 24 hr,And the results were compared with laboratory data，For further research on concrete permeability structure in practical engineering, foundation stability and durability.

Download Full-text