Abstract
Theoretical derivation of local resistance coefficient of sudden expansion tube is presented. Several assumptions are analyzed in the theoretical derivation. That the head loss shall be neglected is affirmed. Experimental data proves that the pressure before and after sudden expansion section is basically the same. That the friction force on the side face of control body is neglected is denied and it is pointed out that such neglect is the main cause for error between theoretical calculation and actual measurement. Experimental device for measuring local resistance coefficient is designed in combination with theoretical derivation process. Optimal gradually varied flow section is selected after sudden expansion pipe in Bernoulli equation based on variation of piezometer tube head. It is pointed out in accordance with experimental data analysis that the value of local resistance coefficient of sudden expansion tube determined through experimental data is closer to the actual situation during pipeline design.
Highlights
Valves, bends and metering devices are installed on pipelines for oil exploitation and transportation to control, adjust and meter the fluid
In 2012, Zhou Zaidong et al concluded through numerical simulation analysis that the bigger Reynolds number leads to more violent eddy, larger effect zone, longer time to reach mainstream and bigger speed at the middle position of the pipeline, and the range affected by the maximum speed is even further from the pipe opening, which conforms to the actual situation [4]
The average value of the error between the local head loss calculated in accordance with local resistance coefficient determined by experiment under different flow rates and the actual measurement is only 1.33%
Summary
Bends and metering devices are installed on pipelines for oil exploitation and transportation to control, adjust and meter the fluid. The flow, direction and even form will be changed when the fluid passes these local parts, which causes the local head loss. The calculation of local head loss of sudden expansion tube when fluid passes is studied in this paper. When the fluid flows into pipeline with bigger diameter, it does not expand suddenly but expand gradually after leaving the pipeline of smaller diameter and forms eddy between corner of. (2015) Experimental Determination of Local Resistance Coefficient of Sudden Expansion Tube. The eddy is driven by the main stream to turn and there is energy consumption during the turning. The fluid impact and collision produced due to sudden change of pipeline section all lead to loss of mechanical energy
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 callDisclaimer: 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.
