Irrigation Pipeline Research Articles

Programming Aided Analysis of Pipeline Irrigation System at Irregular Field Slope Condition

Programming Aided Analysis of Pipeline Irrigation System at Irregular Field Slope Condition

OIL DROP GENERATOR FOR FOLIAR CHEMIGATION: THEORY AND LABORATORY EVALUATION

Precise control of oil drop size optimizes oil retention on plants and oil discharge uniformity along thepipeline for foliar chemigation. However, control of oil drop size with existing chemigation injection systems is difficult. Anew system was developed that injects oil drops of known size distribution into a center pivot irrigation pipeline. Thesystem removes water from the irrigation pipeline, increases water pressure with a pump, injects oil into the water stream,increases dispersion velocity in small diameter tubes in order to break up oil drops, and finally injects the water-oildispersion back into the irrigation pipeline. In order to calculate the maximum drop size (dmax) of viscous oil drops in thedrop generator, a correction term with effective viscosity, effective density, and dispersed phase volume fraction wasadded to the Hinze (1955) equation for dmax in turbulent two-phase pipe flow. The new equation calculates dmax as afunction of water flow rate, oil and water viscosity, oil volume fraction, and other measurable parameters. The averagerelative error and root mean square deviation between dmax and literature data was 3 and 17%, respectively. The tubingin the drop generator is coiled in order to reduce the length of the system; thus, the coiled tubing friction factor must beused in the dmax equation. Two equations (the Ito and Srinivasen equations) for friction factor in helical coiled tubingwere evaluated in laboratory experiments with the drop generator. The Ito equation performed best; average root meansquare deviation between calculated friction factor and experimental data was 2%. Three equations for the effectiveviscosity of oil-water dispersions (the Einstein, Taylor, and Richardson equations) were evaluated with literature andexperimental data. The Richardson equation performed best; average root mean square deviation between calculatedviscosity and experimental and literature data was 7%.

Water Management in a paddy area with pipeline irrigation under the condition of water shortage

Water Management in a paddy area with pipeline irrigation under the condition of water shortage

Experimental Study on Irrigation Pipelines embedded in Stabilized Soft Peaty Ground

Experimental Study on Irrigation Pipelines embedded in Stabilized Soft Peaty Ground

FOIL DROP GENERATOR FOR FOLIAR CHEMIGATION: FIELD EVALUATION

Chemigation field experiments were conducted with a new drop generator for oil-based foliar chemicals. Thedrop generator was adjusted to generate two drop-size distributions with dmax of 980 m and 98 m. Soybean oilconcentration in sprinkler sprays was measured along the 379-m-long center pivot irrigation pipeline; uniformitycoefficients along the center pivot pipeline were 73% and 98%, respectively. An experiment with a conventional straighttube injector was also conducted, and calculated dmax was 1850 m; oil discharge uniformity coefficient along thepipeline was 61%. The calculated drop-size distributions for the three experiments were input into a dispersed phasepipeline transport model; the model calculates oil discharge concentration versus distance along the pipeline. The rootmean square deviation error between experimental and simulated concentration curves were 40%, 28%, and 3% for thestraight tube, 980 m, and 98 m experiments, respectively. The models were used to develop graphs for dischargeconcentration uniformity as a function of dmax and relative density of oil and water in the pipeline. The model simulationsand experiments showed that the drop generator and two-phase transport model provide the ability to control oildischarge concentration uniformity along a center pivot pipeline.

Plannig Procedure for a Pond-Regulated Pipeline Irrigation System for Paddies and the Specifications of the Existing Systems

Plannig Procedure for a Pond-Regulated Pipeline Irrigation System for Paddies and the Specifications of the Existing Systems

Practical technologies for irrigation flow control and measurement

Practical technologies can encourage farmers to adopt practices that support sustainable irrigated agriculture. Important among these are convenient water measurement and control techniques. Many simple constructions or operating procedures are available that can bring considerable convenience to farmers and irrigation delivery system operators. Some are new technologies and some are improvements on older technologies. Many can be implemented with small expense. Some are superior replacements for current practices. The techniques and devices discussed included: (a) accurate and convenient zero setting for weirs and flumes (b) pressure-transducer field checks, (c) easy-to-use scales for orifice and Venturi meters, (d) flow-profile improvers to assist accurate meter operations in irrigation pipelines, (e) floor sills and wave suppressors for canals that usually flow at variable depths of flow, (f) water surface slope measurements–based on static-pressure tubes, and (g) field checks of flow velocity profiles to evaluate flow conditioning using rising-bubble techniques for flow-profile visualization. Many of the concepts are demonstrated in a summary illustration showing several items in a typical stilling well and broad-crested weir (long-throated flume) that need attention, and offers suggestions for correcting the deficiencies.

Modeling of Water Demand on Pipelines for Paddy Field Irrigation

Modeling of Water Demand on Pipelines for Paddy Field Irrigation

An Improved Finite Element Model for Analysis of Irrigation Pipeline Systems

An Improved Finite Element Model for Analysis of Irrigation Pipeline Systems

Inexpensive Pressure Regulation for Irrigation Pipelines

Pressurized pipelines are used on the majority of U.S. irrigated lands. Pressure regulation is needed in many systems with variable topography, and available pressure regulating valves for larger flows are heavy and expensive. An alternative inexpensive, lightweight regulating device is needed. A system to automatically control downstream pressure or flow rate in an irrigation pipeline using a butterfly disk was developed. A spring-loaded cylinder actuator is used to control the butterfly disk angle to maintain a constant pre-set downstream pressure. The unit can be built inexpensively for different pipe sizes. Valve control design equations were developed for predicting the control parameters for different sized pipelines and pressure ranges.

Chemigation Pipeline Transport Model for Nonsoluble Pesticide I. Theory

A mathematical model of dispersed phase transport of a nonsoluble pesticide in an irrigation pipeline is derived. Eulerian and Lagrangian approaches are used at high and low turbulence intensities, respectively. An equation is derived by equating pesticide surface tension and viscous forces to irrigation water drag force at the injection nozzle in order to estimate mean dispersed-phase chemical drop size within the irrigation pipeline.

Settlement and Deformation of Irrigation Pipelines laid on/embedded in Soft Peaty Ground

Settlement and Deformation of Irrigation Pipelines laid on/embedded in Soft Peaty Ground

Friction Coefficient for Center Pivot Systems

An important objective of any center pivot irrigation system is to achieve a uniform distribution of water delivered through the sprinklers. In this study friction coefficients are developed for designing center pivot irrigation systems using two of the most common methods used for estimating friction head loss in sprinkler irrigation pipelines. A center pivot system operating under field conditions was used to verify the analysis. In the analysis, the change of sprinkler discharges along the lateral affects the Reynolds number and hence the state of flow along the lateral has been taken into account. The calculation of friction coefficients and friction head losses from the two equations are compared with the field data.

Venturi Meter Constructions for Plastic Irrigation Pipelines

Venturi tubes or meters, represent one of the oldest and most reliable flow meters that can readily pass the debris frequently accompanying irrigation pipeline deliveries. Standard Venturi constructions, however, are beyond the economic range of interest for farm practice. These investigations of special Venturi meters constructed from plastic pipe fittings attempted to address these economic limitations, fouling problems and water management requirements. Thirty Venturi meters were constructed. They had a main pipe size 30 cm (12 in.) in diameter with a contraction to 20 cm (8 in.) in diameter in the meter throat. With proper technique, the several constructions duplicated calibrations to within about 2%. They establish that individual calibrations are not required for effective applications in irrigation practice.

Shell variation in Australian Notopala (Gastropoda: Prosobranchia: Viviparidae)

Abstract The viviparid snail Notopala is distributed throughout the rivers and other waterbodies of the northern tropical regions of Australia, extending south into the Lake Eyre and Murray-Darling Basins. Despitearecentexarnination of the WesternAustralian viviparids the taxonomy of a number of species, especially those from the Lake Eyre and Murray-Darling Basins, is unclear. Principal Components Analysis was used on seven shell measurements to determine which morphometric characters best delineate the species. Umbilicus width and aperture lip length explained most of the variation. The results suggest that there are four species of Notopala in Australia: N. waterhousii andN. essingtonensis in the north and northwest, N. sublineaca in the Lake Eyre and Murray-Darling Basins and N. hanleyi in the Murray-Darling Basin. With lheapparentextinction of both species ofNotopala in the natural environment of the Murray-Darling Basin, the population of N. hanleyi surviving in a Murray irrigation pipeline and the ...

Short communication. Pipelines as a refuge for freshwater snails

AbstractIn the lower River Murray, Australia, populations of gastropods have declined markedly over the past 40 years. Of the native fauna of about 18 species, only the ancylid Ferrissia petterdi remains common (but in patches), and another five species feature in sporadic local resurgences. Until recently the viviparid Notopala was thought to be extinct. The introduced physid Physa acuta is widespread, but in low numbers. The decline probably is associated with flow regulation, high turbidity and the introduction of common carp. Snail populations have persisted, however, in irrigation pipelines fed from the river, where they periodically cause blockages. This paper reports the discovery of the only known populaion of Notopala hanleyi in a pipeline where the inner wall accumulates microbial and other organic matter, providing high quality food for snails. In the Murray before regulation most of the periphytic biomass was probably microbial, as fluctuating water levels would have maintained littoral communities in a highly productive, early state of succession his postulated that, by stabilizing seasonal water levels, regulation has promoted the production of filamentous green algae, an inferior food source, and so displaced snail populations from the open aquatic environment.

SASK WATER’S STRATEGY FOR SUSTAINABLE IRRIGATION

Sask Water has been involved in the development of pipeline irrigation systems for the past 7 years and have recognized the potential problems which can arise when irrigation is introduced to a dry land setting. By working with local water user associations Sask Water has developed projects which conserve water, avoid social disruptions and leakage associated with canals and minimize return flows.The Luck Lake Irrigation Project constructed by Sask Water under the Canada Saskatchewan Subsidiary Agreement on Irrigation Based Economic Development is an example of Sask Water’s irrigation project approach. Cochrane Lavalin Incorporated (CLI) acted as design engineers and carried out project management and construction management on the project which will ultimately serve 20 000 hectares from Lake Diefenbaker with a pressurized pipeline system. The project has been designed to accommodate the present and future irrigation users as well as other interested water users in the area such as a 2400 ha Heritage Marsh built and operated by Ducks Unlimited Canada. By making the project multi-purpose in nature the benefits of the capital investment in pump stations works can be spread to more users.

HEATED IRRIGATION FOR FROST PROTECTION

An undertree sprinkler [Maxijet] irrigation system designed to deliver 42 to 80 l/hr to each of 570 citrus trees (planted 6.1 × 6.1 m, heights of the larger uniform trees: 2m) was fed through an irrigation water heater [Aquaheet]. The heater added up to a megawatt of heat to the irrigation pipeline by the combustion of diesel fuel. A porous orchard cover (59m × 64m × 3.6m; 0.38ha) sheltered one of six plots of similar size in a citrus orchard on the University of Florida campus in Gainesville. Two border zones, one 3 rows deep on the north border and one on the west tapering from 2 rows on the north to a single row on the south end reduce the edge effect for a total orchard area of 2.12 ha. A minicomputer based data acquisition system provided observations of temperature, wind speed and direction made as frequently as one scan per minute. The effect of the orchard cover, the undertree irrigation, the heated irrigation and combinations of these three methods on the orchard microclimate will be shown in graphs and diagrams of observations taken during the freezes of February 24-26, and December 24-25, 1989. A diagram of the potential effect of water temperature on latent heat transport in the orchard will be discussed as will be problems with documentation of dew point temperature with chilled mirrors under freezing conditions.

HEATED IRRIGATION FOR FROST PROTECTION

An undertree sprinkler [Maxijet] irrigation system designed to deliver 42 to 80 l/hr to each of 570 citrus trees (planted 6.1 × 6.1 m, heights of the larger uniform trees: 2m) was fed through an irrigation water heater [Aquaheet]. The heater added up to a megawatt of heat to the irrigation pipeline by the combustion of diesel fuel. A porous orchard cover (59m × 64m × 3.6m; 0.38ha) sheltered one of six plots of similar size in a citrus orchard on the University of Florida campus in Gainesville. Two border zones, one 3 rows deep on the north border and one on the west tapering from 2 rows on the north to a single row on the south end reduce the edge effect for a total orchard area of 2.12 ha. A minicomputer based data acquisition system provided observations of temperature, wind speed and direction made as frequently as one scan per minute. The effect of the orchard cover, the undertree irrigation, the heated irrigation and combinations of these three methods on the orchard microclimate will be shown in graphs and diagrams of observations taken during the freezes of February 24-26, and December 24-25, 1989. A diagram of the potential effect of water temperature on latent heat transport in the orchard will be discussed as will be problems with documentation of dew point temperature with chilled mirrors under freezing conditions.

Energy loss in branching flow and its application to irrigation pipeline design

Irrigation designers have traditionally relied on simple empirical equations for the evaluation of the energy losses at tee-junctions on irrigation pipelines and for the prediction of outflows from gated pipelines. In this paper an old but apparently little used theory is described, modified slightly and applied to sprinkler and gated irrigation pipelines. It is concluded that the equations based on this theory should replace the empirical equations. It is also shown how the theoretically derived equations can be incorporated into computer programs for the analysis and designs of these systems.