Loading...

Investigation of Shock Wave Generation and Impacts in Methane Supersonic Separator

Amini Magham, Mohammad Reza | 2021

439 Viewed
  1. Type of Document: Ph.D. Dissertation
  2. Language: Farsi
  3. Document No: 54613 (45)
  4. University: Sharif University of Technology
  5. Department: Aerospace Engineering
  6. Advisor(s): Ghorbanian, Kaveh
  7. Abstract:
  8. In general, separation of gas mixtures is grouped in three different methods: adsorption and dissolve methods, membranes and filter methods, and cryogenic methods. One of the most novel and efficient techniques in the latter method, is the supersonic separation where all the expansion, liquefaction, and separation processes are performed within a converging-diverging nozzle with no complex or moving part. This research is focused on methane purification. A one-dimensional model is developed for design and performance analysis of supersonic separators incorporating real gas model, variable specific heat, condensation, and swirling flow. Further, an axisymmetric numerical simulation of the related flow field is performed using commercial software. Results are compared and discussed. Furthermore, the flow structure in the extraction region along with the associated shock wave formation are examined.The obtained results indicate that the swirl intensity might be utilized as an active control mechanism for gas-liquid separation optimization at off-design conditions. It becomes apparent that an increase of pressure and methane mole fraction and a decrease of temperature in inlet flow would increase the required swirl intensity. However, changes in inlet temperature have larger impact to the swirl intensity than changes in pressure or mixture composition. Further, axisymmetic simulation indicates that viscosity and boundary layer formation on the wall would generate losses in flow field. On the other hand, boundary layer growth and blockage would decrease Mach number whereas an increase in temperature and pressure would lower the condensation and methane purity. In addition, results related to condensation and liquid phases show an increase of methane purity in gas phase as well as in temperature and pressure while indicating a decrease of the flow Mach number. Finally, a numerical investigation is carried out on the shock wave formation at the entrance of the extraction branch. It has been found that an increase of the separation wall angle and a decrease of the extraction branch height would intensify and strengthen the shock waves which eventually may get detached and propagate further inside the core flow
  9. Keywords:
  10. Supersonic Separation ; Swirl Intensity ; Shock Wave ; One-Dimensional Model ; Inclined Wave Propagation ; Gases Separation

 Digital Object List

 Bookmark

...see more