Abstract
CFD simulation investigated turbulent flows in equal gas pipeline tees, in which the gas flow completely moves from the main line to the branch. The study was performed for tees of different geometry – stamped with different bending radii of the transition from the branch to the main line and weld, where the main line and branch connection is made at right angles. The outer diameter of the tees varied from 219 mm to 1,420 mm, the bending radius of the transition from the branch to the main line from the minimum permissible to the maximum possible, the pressure in the gas pipeline at the tee location from 3 MPa to 7 MPa. The mathematical model is based on the solution of the Navier-Stokes and energy transfer equations closed by a two-parameter high-Reynolds k – e Launder-Sharma turbulence model. To describe the processes occurring at the wall, the wall function was used. It was found that the bending of the transition from the branch to the main line, the increase in the bending radius lead to a decrease in the intensity of flow separation at the bending point and a decrease in turbulence kinetic energy in recirculation areas. The velocity field of the gas flow after it moves from the main line to the branch becomes more uniform. All this greatly affects the magnitude of hydraulic energy loss of the gas flow in the tees. In this case, the greatest energy losses were observed in the tees located at the lowest pressure points in the gas pipeline system. An analysis of the results showed that if the ratio of the bending radius of the main line and branch connection to the outer diameter is more than 0.25, then the influence of such a tee on the energy loss of the gas pipeline system is minimal. Local resistance coefficients of equal gas pipeline tees are calculated and the resulting equation for their calculation will be useful for specialists designing gas pipeline systems
Highlights
In pipelines of any purpose, there is a loss of hydrodynamic flow energy or pressure loss to overcome resistance caused by pipe wall friction and local resistance
In equal tees of gas pipelines, as a result of complete movement of the gas flow to the branch, the flow is separated from the wall, the flow field in the branch changes dramatically – recirculation and strong turbulent vortices with high kinetic energy occur
The results of CFD simulations showed that the bending of the transition from the branch to the main line, the increase in the bending radius strongly affect the dynamics of the gas flow in the tee
Summary
In pipelines of any purpose, there is a loss of hydrodynamic flow energy or pressure loss to overcome resistance caused by pipe wall friction and local resistance. Modern pipeline systems have a large variety of local resistances, such as tees, branches (hot bends), reducers, and the like. These shaped elements are made by various manufacturers and have varied geometry. There are many complex pipeline systems containing a large number of tees, branches, reducers, and energy loss in the shaped elements of such systems is quite significant and determining in the overall hydraulic resistance of the system. Research on the energy loss of gas flows in shaped elements of pipelines, improvement of their design in order to reduce hydraulic resistance is an urgent task
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Eastern-European Journal of Enterprise Technologies
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
