Amirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297XArticles in Press20240904Numerical and experimental study of trajectory for free falling jetsNumerical and experimental study of trajectory for free falling jets552710.22060/ceej.2024.21277.7674FAFarzinSalmasi29 Bahman boulvard,0000-0002-1627-8598AliTaheri AghdamWater Engineering, Department, University of Tabriz, Tabriz-IranAliHossein Zadeh DalirUniversity of Tabriz,, Department of Water Engineering0000-0003-2359-3921AkramAbbaspourUniversity of Tabriz, Department of Water EngineeringJournal Article20220409In the present study, the trajectory of free falling jets is investigated numerically and experimentally. The results showed that the domain of free falling jet in laboratory work is less than its calculated value using the projectile equations and the sample simulated using Ansys-Fluent software is due to air resistance. The equations of the projectile prediction and the simulated path in Ansys-Fluent have an error of 20.6% and 25.5%, respectively, compared to the laboratory data. Since none of the previously presented equations for calculating the path of falling jets were obtained using laboratory results and did not consider air resistance, therefore, they have errors in calculating the path of falling jets. In the present study, two equations have been presented to calculate the path of the free falling jet, which have a relative error of 3.02% and 9.14%, respectively. These relationships significantly reduce the error of calculating the path of the free-falling jet. By reducing the outlet cross section of the free falling jet and increasing the head passing through the dam spillway, the free falling jet reaches the ground at a greater distance from the dam body. Since none of the equations presented for calculating the trajectory of jets have been obtained using laboratory results and have not considered air resistance, so they have an average error of 21% in estimation of trajectory jet. In the present study,In the present study, the trajectory of free falling jets is investigated numerically and experimentally. The results showed that the domain of free falling jet in laboratory work is less than its calculated value using the projectile equations and the sample simulated using Ansys-Fluent software is due to air resistance. The equations of the projectile prediction and the simulated path in Ansys-Fluent have an error of 20.6% and 25.5%, respectively, compared to the laboratory data. Since none of the previously presented equations for calculating the path of falling jets were obtained using laboratory results and did not consider air resistance, therefore, they have errors in calculating the path of falling jets. In the present study, two equations have been presented to calculate the path of the free falling jet, which have a relative error of 3.02% and 9.14%, respectively. These relationships significantly reduce the error of calculating the path of the free-falling jet. By reducing the outlet cross section of the free falling jet and increasing the head passing through the dam spillway, the free falling jet reaches the ground at a greater distance from the dam body. Since none of the equations presented for calculating the trajectory of jets have been obtained using laboratory results and have not considered air resistance, so they have an average error of 21% in estimation of trajectory jet. In the present study,https://ceej.aut.ac.ir/article_5527_10898777c3ed35c6f8f09a0a4c1f49d3.pdf