Investigation of local pressure losses in reducers for sprinkler irrigation systems: Experimental, analytical and CFD approaches

Yıl 2025, Cilt: 62 Sayı: 4, 435 - 449, 12.12.2025

Vedat Demir , Hüseyin Yürdem

https://doi.org/10.20289/zfdergi.1623449

Öz

Objective: This study aims to investigate the local pressure losses for conical reducers used in sprinkler irrigation systems using experimental, analytical, and Computational Fluid Dynamics (CFD) methods.
Material and Methods: Eight different reducers with nominal outer diameters of 90-75, 110-90, and 110-75 mm were considered. In the experiments, the pressure losses in the reducers were measured at different water flow rates. The CFD analysis was carried out using the Realizable k-ε, SST k-, and RSM turbulence models. The pressure loss coefficients were determined by measurements, analytically, and CFD analysis and were compared with each other.
Results: Taking the experimental data into account, the local loss coefficients for the R19075, R29075, R411090, and R511090, reducers were determined to be values between 0.5 and 1.0. The R611075, and R711075, R811075 reducers local loss coefficients between 0.8 and 1.5 were determined. The local loss coefficients determined using the SST k- turbulence model considered in the CFD analysis were in better agreement with the experimental results.
Conclusion: It can be said that the pressure losses in the newly designed reducers could be determined by the CFD analysis at the design stage, and it would be useful to use these values in the system design.

Anahtar Kelimeler

CFD , conical contraction , fitting , local friction loss , minor pressure loss , reduction

Yağmurlama sulama sistemlerinde kullanılan redüksiyonlarda basınç kayıplarının incelenmesi: Deneysel, sayısal ve CFD yaklaşımlarıyla

Öz

Amaç: Çalışmada, yağmurlama sulama sistemlerinde kullanılan redüksiyonlar için yerel basınç kayıplarının deneysel, analitik ve Hesaplamalı Akışkanlar Dinamiği (CFD) yöntemleri ile incelenmesi amaçlanmıştır.
Materyal ve Yöntem: Çalışmada, nominal dış çapları 90-75, 110-90 ve 110-75 mm olan sekiz farklı redüksiyon dikkate alınmıştır. Denemelerde, redüksiyonlardaki basınç kayıpları farklı su geçiş debilerinde ölçülmüştür. Redüksiyonlardaki basınç kayıpları, teorik eşitliklerle ve Reliazable k-ε, SST k- ve RSM türbülans modelleri dikkate alınarak CFD analiz yöntemiyle incelenmiştir.
Araştırma Bulguları: Deneysel veriler dikkate alındığında yerel kayıp katsayıları, R19075, R29075, R411090, R511090 redüksiyonları için 0.5 ile 1.0 arasında ve R611075, R711075, R811075 redüksiyonları için ise 0.8 ile 1.5 arasında belirlenmiştir. Sayısal analiz yönteminde SST k- türbülans modeli kullanılarak belirlenen yerel kayıp katsayıları, deneysel sonuçlar ile en iyi uyumu göstermiştir.
Sonuç: Yeni tasarlanan redüksiyonlardaki basınç kayıplarının tasarım aşamasında sayısal analiz yöntemi ile belirlenebileceği ve sistem tasarımında kullanılmasının uygun olacağı söylenebilir.

Anahtar Kelimeler

HAD , konik daralma , ekleme parçası , lokal sürtünme kaybı , yerel basınç kaybı , redüksiyon

Kaynakça

• ANSYS, 2016. Fluent theory guide R.17.2. Canonsburg, PA: ANSYS, Inc., 850 pp.
• ASAE, 2003. Procedure for testing and reporting pressure losses in irrigation valves. ASAE S447, Feb03, ASAE Standards 2003: 941-943.
• Bagarello, V., V. Ferro, G. Provenzano & D. Pumo, 1997. Evaluating pressure losses in drip-irrigation lines. Journal of Irrigation and Drainage Engineering, 123 (1): 1-7. https://doi.org/10.1061/(ASCE)0733-9437
• Cengel, Y. A. & J. M. Cimbala, 2006. Fluid Mechanics: Fundamentals and Applications (1st edition). NY: McGraw-Hill, 940 pp.
• Choi, S. H., S. Kim, J. Choi, J. T. Park & H. Jeong, 2019. Optimum angles of non-standard diffusers and reducers for engineering application. Journal of Mechanical Science and Technology, 33 (10): 4831-4841.
• Crane, 1982. Flow of fluids through valves, fittings, and pipe. Joliet, IL: Metric Edition Crane Co, 133 pp.
• Cürebal, T., 2016. Boru ekleme parçalarındaki akışın üç boyutlu incelenmesi. Karadeniz Teknik Üniversitesi, (Unpublished), Trabzon, 71 pp.
• Das, P., M.M.K. Khan, M.G. Rasul & S. C. Saha, 2015. “Fluid flow charactericitics on scale deposition in a concentric reducer using CFD approach, 878-883”. 11th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics (20-23 July 2015, South Africa), 883 pp.
• Daugherty, R. L. & J. B. Franzini, 1965. Fluid mechanics with engineering applications. (6th edition). NY: McGraw-Hill Book Company, 574 pp.
• Deev, A. V., T. Rasheed, M. C. Welsh, M. M. K. Khan & M. G. Rasul, 2009. Measurement of instantaneous flow velocities in a concentric reducer using particle image velocimetry: Study of scale deposition. Experimental Thermal and Fluid Science, 33 (6): 1003-1011.
• Demir, V., H. Yürdem, A. Yazgı & T. Günhan, 2019. Measurement and prediction of total friction losses in drip irrigation laterals with cylindrical integrated in-line drip emitters using CFD analysis method. Journal of Agricultural Sciences, 25 (3): 354-366. https://doi.org/10.15832/ankutbd.433830
• Demir, V., H. Yürdem, A. Yazgı & T. Günhan, 2020. Determination of the hydraulic properties of a flat type drip emitter using computational fluid dynamics. Tarim Bilimleri Dergisi - Journal of Agricultural Sciences, 26 (2): 226-235. https://doi:10.15832/ankutbd.492686
• Demir, V., H. Yürdem, A. Yazgı & T. Günhan, 2022. Mikro jet yağmurlama sulama başlığında akış özelliklerinin hesaplamalı akışkanlar dinamiği ile incelenmesi. Ege Univ. Ziraat Fak. Derg., 59 (1): 93-105, https://doi.org/10.20289/zfdergi.929494
• Howell, T. A. & F. A. Barinas, 1980. Pressure losses across trickle irrigation fittings and emitters. Transactions of the ASAE, 23 (4): 928-933.
• Idel'chik, I. E., 1960. Handbook of hydraulic resistance: Coefficients of local resistance and of friction. Israel Program for Scientific Translations, 517 pp.
• Jivani, G. & K. Naik, 2019. CFD Simulation and analysis of fluid flow through concentric reducer pipe fitting. International Research Journal of Engineering and Technology, 9: 1071-1076.
• Juana, L., L. Rodrı´guez-Sinobas & A. Losada, 2002. Determining minor head losses in drip irrigation laterals I: Methodology. Journal of Irrigation and Drainage Engineering, 128 (6): 376-384.
• Munson, B. R., D. F. Young & T. H. Okiiski, 2002. Fundamentals of Fluid Mechanics (4th edition). Hoboken, NJ: John Wiley & Sons, Inc, 836 pp.
• Narayane, M. A. V., M. V. C. Pathade & M. R. G. Telrandhe, 2014. CFD analysis of water flow through gradual contraction joint. International Journal of Engineering Research, 3 (6): 1579-1581.
• Ntengwe, F., M. Chikwa & L. Witika, 2015. Evaluation of friction losses in pipes and fittings of process engineering plants. International Journal of Scientific and Technology Research, 4 (10): 330-336.
• Palau-Salvador, G., J. Arviza-Valverde & V. F. Bralts, 2004. “Hydraulic flow behavior through an in-line emitter labyrinth using CFD techniques, 1-8”. Proceedings of the ASAE/CSAE Annual International Meeting (2024, Ottawa, Canada). ASABE Paper No. 042252, 8 pp.
• Provenzano, G. & D. Pumo, 2004. Experimental analysis of local pressure losses for micro-irrigation laterals. Journal of Irrigation and Drainage Engineering, 130 (4): 318-324.
• Rennels, D. C. & H. M. Hudson, 2012. Pipe flow: A practical and comprehensive guide. Hoboken, NJ: John Wiley & Sons, Inc, 289 pp.
• Roul, M. K. & S. K. Dash, 2011. Two-phase pressure drop caused by sudden flow area contraction/expansion in small circular pipes. International Journal for Numerical Methods in Fluids, 66 (11): 1420-1446.
• Saldivia, L. A., V. F. Bralts, W. H. Shayya & L. J. Segerlind, 1990. Analysis of sprinkler irrigation system components using the finite element method. Transactions of the ASAE, 33 (4): 1195-1202.
• Satish, G., K. A. Kumar, V. V. Prasad & S. M. Pasha, 2013. Comparison of flow analysis of a sudden and gradual change of pipe diameter using fluent software. International Journal of Research in Engineering and Technology, 2: 41-45.
• Tan, W. C., C. W. Chan, L. E. Aik & A. AnasRahman, 2013. “Scale deposition analysis of fluid flow characteristic in a concentric reducer using CFD approach, (1-9)”. Paper ID: P288. International Conference on Mechanical Engineering Research (ICMER2013), (1-3 July 2013, Bukit Gambang Resort City, Kuantan, Pahang, Malaysia), 539 pp.
• TS, 2019. Polietilen (PE) borular-Mekanik boru bağlantı sistemlerinde basınç düşmesi-Deney metodu ve özellikler.TS 6694, Türk Standardları Enstitüsü, Ankara, 6 pp.
• Wang, L. Y., Z. C. Zheng, Y. X. Wu, J. Guo, J. Zhang & C. Tang, 2009. Numerical and experimental study on liquid-solid flow in a hydrocyclone. Journal of Hydrodynamics, Ser B, 21 (3): 408-414. https://doi.org/10.1016/S10016058(08)60164-X
• Wei, Q., Y. Shi, W. Dong, G. Lu & S. Huang, 2006. Study on hydraulic performance of drip emitters by computational fluid dynamics. Agricultural Water Management, 84 (1): 130-136. https://doi.org/10.1016/j.agwat.2006.01.016
• White, F. M., 2001. Fluid Mechanics (4th edition). New York: McGraw-Hill, Inc, 826 pp.
• Willmott, C. J. & K. Matsuura, 2005. Advantages of the mean absolute error (MAE) over the root mean square error (RMSE) in assessing average model performance. Climate Research, 30 (1): 79-82. https://doi.org/10.3354/cr030079
• Willmott, C. J., S. G. Ackleson, R. E. Davis, J. J. Feddema, K. M. Klink, D. R. Legates, J. O'donnell & C. M. Rowe, 1985. Statistics for the evaluation and comparison of models. Journal of Geophysical Research: Oceans, 90: 8995-9005.
• Zhang, J., W. Zhao, Z. Wei, Y. Tang & B. Lu, 2007. Numerical and experimental study on hydraulic performance of emitters with arc labyrinth channels. Computers and Electronics in Agriculture, 56 (2): 120-129.