caa a22 4500 445837829 CHVBK 20180317145335.0 cr unu---uuuuu 170323e20110701xx s 000 0 eng 10.1007/s00271-010-0240-6 doi (NATIONALLICENCE)springer-10.1007/s00271-010-0240-6 Hydraulics of microtube emitters: a dimensional analysis approach [Elektronische Daten] [P. Vekariya, R. Subbaiah, H. Mashru] Dimensional analysis is a simple, clear and intuitive method for determining the functional dependence of physical quantities that are of importance to a certain process. Buckingham's pi theorem is used to derive a dimensionally homogeneous equation for predicting the discharge of the microtube as a function of gravitational acceleration (g), microtube diameter (D), operating pressure head (H) and microtube length (L). Experimental investigations were conducted at College of Agricultural Engineering and Technology, Junagadh, to determine (a) the variation in Q with L, D and H and (b) the coefficients (K, y and z) of the developed model. The L and D of microtube were varied from 5 to 250 cm and 1.2 to 2mm. The operating pressure was varied from 0 to 1.5m. The L, H and D combinations selected in the study suit most of the manufacturer's recommendations for microtube drip irrigation systems. The discharge of microtube decreased with increase in microtube length for particular microtube diameter and operating pressure. The discharge increased with increase in the microtube diameter for a particular operating pressure and microtube length. The values of K, y and z are 4.476, 1 and 0.5, respectively. Goodness of fit and efficiency coefficient reduced with increase in the microtube diameter. The dimensionally homogeneous equation (Eq.25) developed for all flow regimes can predict discharge with good accuracy for less than 2-mm microtube diameter. The microtube diameter was found to be 1.2mm based on the dominance of viscous forces over inertial forces. Springer-Verlag, 2010 Vekariya P. Soil and Water Engineering Department, College of Agricultural Engineering and Technology, Junagadh Agricultural University, 362001, Junagadh, India aut Subbaiah R. Centre of Excellence on Soil and Water Management, Office of Research Scientist (Agricultural Engineering), Junagadh Agricultural University, 362001, Junagadh, India aut Mashru H. Centre of Excellence on Soil and Water Management, Office of Research Scientist (Agricultural Engineering), Junagadh Agricultural University, 362001, Junagadh, India aut Irrigation Science Springer-Verlag 29/4(2011-07-01), 341-350 0342-7188 29:4<341 2011 29 271 https://doi.org/10.1007/s00271-010-0240-6 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00271-010-0240-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Vekariya P. Soil and Water Engineering Department, College of Agricultural Engineering and Technology, Junagadh Agricultural University, 362001, Junagadh, India aut NATIONALLICENCE 700 1- Subbaiah R. Centre of Excellence on Soil and Water Management, Office of Research Scientist (Agricultural Engineering), Junagadh Agricultural University, 362001, Junagadh, India aut NATIONALLICENCE 700 1- Mashru H. Centre of Excellence on Soil and Water Management, Office of Research Scientist (Agricultural Engineering), Junagadh Agricultural University, 362001, Junagadh, India aut NATIONALLICENCE 773 0- Irrigation Science Springer-Verlag 29/4(2011-07-01), 341-350 0342-7188 29:4<341 2011 29 271 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer