Design of Zero Slope Microirrigation Laterals: Effect of the Friction Factor Variation

AbstractMicroirrigation has become quite a common practice in agricultural production in various parts of the world. To achieve the optimum (hydraulic and economic) system performance, designers are often faced with the problem of designing a maximum lateral length which results in a desired coefficient of uniformity (CU) or an allowable pressure head variation (δH). Previous theoretical design approaches are usually based on a constant Darcy–Weisbach (DW) friction factor along the lateral and this assumption can lead to substantial errors. In the research reported in this paper, a new analytical design approach does not require the constant DW assumption for zero-slope laterals while it still takes into account the emitter exponent and the effect of minor friction losses caused by emitters. Assuming a constant friction factor along the lateral might result in errors up to 14% in the calculation of the maximum lateral length. Conversely, the maximum relative error caused by the application of the proposed...

[1]  Zayani Khemaies,et al.  Design of Level Ground Laterals in Trickle Irrigation Systems , 2009 .

[2]  A. I. Al-Amoud,et al.  A computer program for trickle irrigation lateral design considering emitter losses. , 2000 .

[3]  Gürol Yıldırım,et al.  An assessment of hydraulic design of trickle laterals considering effect of minor losses , 2007 .

[4]  Sayed-Hossein Sadeghi,et al.  Adjusted friction correction factors for center-pivots with an end-gun , 2011, Irrigation Science.

[5]  Terry A. Howell,et al.  Designing Trickle Irrigation Laterals for Uniformity , 1974 .

[6]  Wm. E. Hart,et al.  Analytical Design of Sprinkler Systems , 1965 .

[7]  Zayani Khemaies,et al.  Design of Nonzero Uniformly Sloping Laterals in Trickle Irrigation Systems , 2013 .

[8]  Terry A. Howell,et al.  Pressure losses across trickle irrigation fittings and emitters. , 1980 .

[9]  Giuseppe Provenzano,et al.  Simplified Procedure to Evaluate Head Losses in Drip Irrigation Laterals , 2005 .

[10]  Ahmed I. Al-Amoud,et al.  Significance of Energy Losses Due to Emitter Connections in Trickle Irrigation Lines , 1995 .

[11]  I. P. Wu.  Energy gradient line approach for direct hydraulic calculation in drip irrigation design , 2004, Irrigation Science.

[12]  Helmi M. Hathoot,et al.  Analysis and Design of Trickle‐Irrigation Laterals , 1993 .

[13]  John D. Valiantzas.  Analytical Approach for Direct Drip Lateral Hydraulic Calculation , 1998 .

[14]  Giuseppe Provenzano,et al.  Experimental Analysis of Local Pressure Losses for Microirrigation Laterals , 2004 .

[15]  Nicola Lamaddalena,et al.  DESIGN OF DRIP LINE IN IRRIGATION SYSTEMS USING THE ENERGY DROP RATIO APPROACH , 2001 .

[16]  V. F. Bralts,et al.  An improved finite element model for the analysis of microirrigation systems , 1995 .

[17]  Sayed-Hossein Sadeghi,et al.  Analytical Determination of Distribution Uniformity for Microirrigation Tapered Laterals Laid on Uphill and Horizontal Slopes , 2013 .

[18]  S. F. Mousavi,et al.  FACTOR H FOR THE CALCULATION OF HEAD LOSS AND SIZING OF DUAL-DIAMETER LATERALS , 2012 .

[19]  I-Pai Wu,et al.  Drip Irrigation Design Based on Uniformity , 1974 .

[20]  Yaohu Kang,et al.  Evaluation of Microirrigation Uniformity on Laterals Considering Field Slopes , 2010 .

[21]  Leonor Rodríguez-Sinobas,et al.  Determining minor head losses in drip irrigation laterals. II: Experimental study and validation , 2002 .

[22]  Soichi Nishiyama,et al.  Analysis and Design of Microirrigation Laterals , 1996 .

[23]  Vincent F. Bralts,et al.  Drip irrigation design and evaluation based on the statistical uniformity concept , 1987 .

[24]  John D. Valiantzas,et al.  Continuous Outflow Variation along Irrigation Laterals: Effect of the Number of Outlets , 2002 .

[25]  Sayed-Hossein Sadeghi,et al.  Closure to ‘‘Analytical Determination of Distribution Uniformity for Microirrigation Tapered Laterals Laid on Uphill and Horizontal Slopes’’ by Sayed Hossein Sadeghi and Troy Peters , 2014 .

[26]  I-Pai Wu,et al.  An assessment of hydraulic design of micro-irrigation systems , 1997 .

[27]  I-Pai Wu,et al.  Drip Irrigation Design on Nonuniform Slopes , 1979 .

[28]  K. Zayani,et al.  Design of Trickle Irrigation Laterals Using Energy Drop Ratio Approach , 2008 .

[29]  Muluneh Yitayew,et al.  Trickle lateral hydraulics II: Design and examples , 1988 .

[30]  Sayed-Hossein Sadeghi,et al.  Closure to “Modified G and GAVG Correction Factors for Laterals with Multiple Outlets and Outflow” by Sayed-Hossein Sadeghi and Troy Peters , 2014 .

[31]  Sayed-Hossein Sadeghi,et al.  Modified G and GAVG Correction Factors for Laterals with Multiple Outlets and Outflow , 2011 .

[32]  John D. Valiantzas.  Modified Hazen–Williams and Darcy–Weisbach Equations for Friction and Local Head Losses along Irrigation Laterals , 2005 .

[33]  Muluneh Yitayew,et al.  Trickle Lateral Hydraulics. I: Analytical Solution , 1988 .

[34]  Jack Keller,et al.  Sprinkle and Trickle Irrigation , 1990 .

[35]  Raúl Sánchez,et al.  Analytical Relationships for Designing Rectangular Drip Irrigation Units , 2004 .

[36]  Pedro Vallesquino.  An approach for simulating the hydraulic performance of irrigation laterals , 2008, Irrigation Science.

[37]  Roland W Jeppson,et al.  Analysis of Flow in Pipe Networks , 1976 .