Match!

Friction Correction Factor For Center‐Pivot Irrigation Systems

Published on Feb 1, 1988in Journal of Irrigation and Drainage Engineering-asce1.34
· DOI :10.1061/(ASCE)0733-9437(1988)114:1(183)
J. Mohan Reddy3
Estimated H-index: 3
,
Horacio M. Apolayo2
Estimated H-index: 2
Abstract
A friction correction factor (Fcp) for use in the estimation of friction loss in a center-pivot irrigation system lateral is derived. The results obtained using the Fcp are compared with the results obtained using other methods of estimating friction loss. A significant difference in the estimated friction loss was observed between this coefficient and the one derived by Christiansen for linear-move sprinkler systems.
  • References (1)
  • Citations (17)
📖 Papers frequently viewed together
16 Citations
21 Citations
1990
450 Citations
78% of Scinapse members use related papers. After signing in, all features are FREE.
References1
Newest
#1S.T. ChuH-Index: 1
5 Citations
Cited By17
Newest
Source
#1Dilshad BrarH-Index: 1
#2William L. KranzH-Index: 12
Last. Derrel L. MartinH-Index: 21
view all 5 authors...
Abstract. Corner watering attachments, specifically end guns and corner extensions, attached to center pivot systems are a common means to irrigate corners of square fields. The pumping plant is designed to supply water to all sprinklers when the center pivot is irrigating the point of maximum elevation. Most designs include powering the irrigation pumping plant at a fixed speed which can lead to excessive energy use. Variable frequency drives (VFD) were introduced to adjust pump speed in respon...
1 CitationsSource
AbstractIn this paper, efficient closed form expressions to compute the friction head loss in center-pivot laterals using the method of the discrete outflow distribution are presented. The results are applicable to center-pivot systems with single diameter and multidiameter, with constant spacing between sprinklers along the lateral, with and without end gun sprinklers, and with and without closed outlets at the beginning of the lateral. The head loss between the last outlet and the end gun, usu...
Source
This paper presents efficient closed form expressions, based on the discrete outflow distribution, to compute the friction head loss and the friction correction factor in center-pivot laterals divided into several reaches. Since such formulas cannot be found in the literature, we develop these expressions based on the discharge required by each sprinkler and each reach to irrigate an annular area. These expressions can be used in center-pivot laterals with and without end gun sprinkler and with ...
Source
#1Sayed-Hossein Sadeghi (IUT: Isfahan University of Technology)H-Index: 8
#2Troy Peters (WSU: Washington State University)H-Index: 8
A new method for calculating total friction head loss in center-pivots with an operational end-gun was developed. The proposed methodology is based on adjusting the previous friction correction factors for center-pivots with end-guns in order to correct their paradoxes and shortcomings. Equations presented in the current work are developed for center-pivots with a finite number of outlets along the lateral and constant outlet spacing and discharge as well as constant discharge and variable spaci...
9 CitationsSource
#1M. I. Valín (Technical University of Lisbon)H-Index: 1
#2M.R. Cameira (Technical University of Lisbon)H-Index: 14
Last. Luis S. Pereira (Technical University of Lisbon)H-Index: 57
view all 4 authors...
Center-pivot sprinkler irrigation became very popular. Hence, aimed at farmers advising, the simulation model DEPIVOT has been developed with the objective of design new systems or changes in systems in operation. The software consists of a simulation package developed in Visual Basic and data base in Access. The model comprises five main sub-models for: (a) computation of the gross irrigation requirements; (b) sizing of the lateral pipe spans through the hydraulics computation of the friction l...
18 CitationsSource
Friction head loss equations and friction correction factors were evaluated and compared to field observations collected from thirty center pivots with laterals made of PVCs. The friction head loss equations include Darcy-Weisbach (D-W), Hazen-Williams (H-W), and Scobey, in addition to a proposed equation valid for smooth and rough pipe types and for all turbulent flow types. The proposed equation was developed by combining the equations of D-W and H-W, along with the multiple nonlinear regressi...
25 CitationsSource
The classical expressions obtained through the mathematical theory of friction head loss along the center-pivot lateral are adequate for many existing center-pivots. Nevertheless, several important aspects are not accounted for in the classic approaches, such as the presence of closed outlets at the beginning of the center-pivot and the friction head loss that occurs between the last sprinkler and the end gun. Furthermore, the irrigated radius and area considered in classical approaches are diff...
4 CitationsSource
#1Luigi Berardi (University of Bari)H-Index: 16
#2Orazio Giustolisi (University of Bari)H-Index: 29
Last. Ezio Todini (UNIBO: University of Bologna)H-Index: 32
view all 3 authors...
The global gradient algorithm (GGA) is the most widely adopted method for steady-state analysis of water distribution networks. It is used to solve the non-linear system of equations describing mass and energy conservation laws. Nonetheless, it has been recently proved that the usually adopted representation of distributed pipe demands as lumped withdrawals at ending nodes causes inconsistent calibration results and pipe head loss errors which could be non negligible in some network conditions. ...
15 CitationsSource
#1Thamer Ahmed Mohammed (UPM: Universiti Putra Malaysia)H-Index: 8
#2Abdul Halim GhazaliH-Index: 14
Last. Mohd Amin Mohd SoomH-Index: 3
view all 4 authors...
G-factor is used to compute the head loss due to friction in manifolds. There are many formulae derived to compute the G-factor for manifolds. But most of these formulae were derived based on the theoretical basis with assumptions. The formulae of G-factor can be divided into two types. The first type was based on the location of the first outlet from the beginning of the manifold length while the second type was based on the end condition of the manifold (open or closed). In this study, a test ...
1 Citations