Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


36574.pdf (7.84 MB)

ETD Abstract Container

Abstract Header

Analysis of Energy Separation in Vortex Tube using RANS based CFD

Cuddalore Balakumar, Karthik Vigneshwar, M.S.
http://orcid.org/0000-0003-0079-726X
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1592136625323737

Abstract Details

2020, MS, University of Cincinnati, Engineering and Applied Science: Aerospace Engineering.
In the current thesis, an analysis of energy separation in a Ranque-Hilsch Vortex Tube (RHVT or simply VT) using results from CFD has been performed. Initially the 3D CFD model of the VT was validated against published experimental data and was found to have a very good agreement in terms of total temperature predictions at the hot and cold outlets. The flowfield in the VT was analyzed using RANS based two-equation turbulence model Std k-?. Comparisons were made between a published LES research to get an idea of how the turbulence models differed in their predictions of highly swirling flows like the vortex tube flow which exhibit an anisotropic behavior with respect to turbulence production and the stresses resultantly. The velocities were studied in detail to define the free and forced vortex regions which are found in swirling flows and also to define the cross-over region between the two counter-flowing streams of hot and cold fluid where turbulent stresses and generation of turbulence are expected to be maximum. The turbulence generated at the cross-over region breaks down in the annular region affected by viscosity near walls which causes the turbulence breakdown to heat neat the walls and thus the hot temperature. Next, the other flow properties like the static and total temperatures, vorticity, strain rate and Reynolds stresses inside the VT were studied in detail using the results from the CFD simulation which would have been otherwise very difficult to obtain using experimental techniques. In the further analysis, it was found that there is a flow of energy in the form of work and heat from the core flow to the annular flow region which causes the core flow temperature to drop and that of the annular flow to increase. A control volume (CV) analysis was performed with the cold flow forming the control volume and the CV boundary being defined by the cross-over region between the cold and hot flow. The calculations were in very good agreement with the assumptions made regarding the heat and work transfer. The analysis revealed that the shear work was the dominant mode of work transfer, which was performed by the cold flow on the hot flow and also a presence of turbulent heat conduction due to the eddies away from the core flow. The heat transfer was found to be only a fraction of the shear work transfer that is present.
Peter Disimile, Ph.D. (Committee Chair)
Shaaban Abdallah, Ph.D. (Committee Member)
Milind Jog, Ph.D. (Committee Member)
98 p.
Engineering
Vortex Tube mechanics; Energy Separation; RANS CFD; Swirling Flow; Reynolds Stress; Heat and Work Transfer

Recommended Citations

Citations

  • Cuddalore Balakumar, K. V. (2020). Analysis of Energy Separation in Vortex Tube using RANS based CFD [Master's thesis, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1592136625323737

    APA Style (7th edition)

  • Cuddalore Balakumar, Karthik Vigneshwar. Analysis of Energy Separation in Vortex Tube using RANS based CFD. 2020. University of Cincinnati, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1592136625323737.

    MLA Style (8th edition)

  • Cuddalore Balakumar, Karthik Vigneshwar. "Analysis of Energy Separation in Vortex Tube using RANS based CFD." Master's thesis, University of Cincinnati, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1592136625323737

    Chicago Manual of Style (17th edition)

ucin1592136625323737
483
© 2020, all rights reserved.
This open access ETD is published by University of Cincinnati and OhioLINK.