DOI QR코드

DOI QR Code

Flow Characteristics Investigation of Gel Propellant with Al2O3 Nano Particles in a Curved Duct Channel

Al2O3 나노입자가 젤(Gel) 추진제의 곡관 유동특성에 미치는 연구

  • 오정수 ((주)대주기계 유체기계기술연구소) ;
  • 문희장 (한국항공대학교 항공우주 및 기계공학부)
  • Received : 2013.04.09
  • Accepted : 2013.05.22
  • Published : 2013.06.01

Abstract

Curved duct channel flow characteristics for non-Newtonian gel fluid is investigated. A simulant gel propellant mixed by Water, Carbopol 941 and NaOH solution has been chosen to analyze the gel propellant flow behavior. Rheological data have been measured prior to the flow analysis where water-gel propellant and water-gel propellant with $Al_2O_3$ nano particles are both used. The critical Dean number examined by the numerical simulation in the U-shape duct flow reveals that although water-gel-nano propellants have higher apparent viscosity, the critical Dean number do show no notable difference for both the two gel propellant. It is found that the power-law index may be a dominant parameter in determining the critical Dean number and that the gel with particles addition may be more vulnerable to Dean instability.

본 연구에서는 곡관 채널에서의 비뉴튼 젤 추진제의 유동 특성에 대해 연구하였다. 물을 기본유체로 하는 모사젤을 Carbopol 941 젤화 작용제와 NaOH 농축액을 혼합하여 제작하였으며 입자 유무에 따른 유동 특성을 파악하기 위해 $Al_2O_3$ 나노 입자가 첨가된 젤을 제작하여 두 젤 추진제간의 유변학적 특성을 비교하였다. 두 모사젤에 대해 U-자형의 곡관부 위치별 유동특성과 Dean 와류(vortices)의 경향은 상이하였으나 나노 입자가 첨가된 모사젤 추진제의 경우 높은 컨시스턴시 지수에도 불구하고 두 모사젤 모두 비슷한 범위의 임계 Dean 수를 도출하였다. 나노 입자 첨가 유무와 무관하게 power-law 지수값이 임계 Dean 수를 결정하는데 주요 변수임을 판단할 수 있었으나 나노입자가 첨가된 젤의 경우 Dean 와류 강도의 변동폭이 상대적으로 크다는 결론을 내릴 수 있었다.

Keywords

References

  1. Hermans, P. H., Gels, in Colloid Science II, Kruyt, H.R. (Ed.), Elsevier Publ. Co., Amsterdam, 1949, pp.483-494
  2. Natan, B. and Rahimi, S., "The Status of Gel Propellants in Year 2000," in Combustion of Energetic Materials, 2001, pp.172-194
  3. Bryan, P., John, J., Kevin, B., and Kim, K., "Metalized Gelled Propellants Combustion Experiments in a Pulse Detonation Engine," NASA/TM2006-214119, 2006
  4. Kuznetsov, A., Solomon, Y., and Natan, B., "Development of a Lab-Scale Gel Fuel Ramjet Combustor," 46th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 2010, AIAA-2010-7124
  5. Chun, K. S., Locke, R. J., Lee, C. M., and Ratvasky, W. J., "Focused Schlieren Flow Visualization Studies of Multiple Venturi Fuel Injectors in A High Pressure Combustor," AIAA 32nd Aerospace Sciences Meeting & Exhibit, January 1994
  6. Rahimi, S. and Natan, B., "Atomization Characteristics of Gel Fuels," AIAA Paper 98-3830, 1998
  7. Chojnacki, K. T. and Feikema, D. A., "Atomization Studies of Gelled Liquids," AIAA Paper 94-2773, 1994
  8. Yoon, C., Heister, S., Xia, G., and Merkle, C., "Numerical Simulations of Gel Propellant Flow through Orifice," AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 2009
  9. Yoon, C., Heister, S., Xia, G., and Merkle, C., "Simulations of Injection of Shear-Thinning Gel Propellant Through Plain-Orifice Atomizer," AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 2010
  10. Rahimi, S. and Natan, B., "Numerical Solution of the Flow of Power-Law Gel Propellants in Converging Injectors", Propellants, Explosives, Pyrotechnics, Vol. 25, Issue 4, 2000, pp.203-212 https://doi.org/10.1002/1521-4087(200009)25:4<203::AID-PREP203>3.0.CO;2-E
  11. Tang, H. S. and Kalyon, D. M., "Estimation of the Parameters of Herschel-Bulkley Fluid under Wall Slip Using a Combination of Capillary and Squeeze Flow Viscometers," Rheologica Acta 43 (1), 2004, pp.80-88 https://doi.org/10.1007/s00397-003-0322-y
  12. 한정식, 정병훈, "램제트용 연료의 특성연구," 국방과학연구소, TEDC-121-041238, 2004
  13. 정병훈, 고승원, 황갑성, 한정식, 홍명표, "슬러리와 젤 추진제의 기술개발 동향," 한국추진공학회 2007년도 춘계학술대회 논문집, 2007, pp.168-171
  14. 황태진, 이인철, 김상선, 구자예, "Water-Gel 모사 추진제의 충돌 분무 특성 연구," 한국추진공학회 2009년도 추계학술대회 논문집, 2009, pp.11-14
  15. 오정수, 전두성, 최상태, 김덕윤, 최양호, 이정혁, 문희장, "인젝터 형상 변화에 따른 Gel 추진제의 유동 특성 연구," 한국추진공학회 2010년도 추계학술대회 논문집, 2010, pp.300-303
  16. 김재우, 전두성, 신웅섭, 이효미, 문희장, "제작방법에 따른 모사 젤 추진제의 특성 연구," 한국추진공학회 2011년도 추계학술대회 논문집, 2011, pp.467-470
  17. 김재우, 전두성, 강태곤, 장석필, 구자예, 문희장, "$SiO_2$ 계열 젤화제에 따른 케로신 젤연료의 유변학적 특성 연구," 한국추진공학회지, 제16권, 제6호, 2012, pp.32-40 https://doi.org/10.6108/KSPE.2012.16.6.023
  18. Baek, G., "Rheological Properties and Atomization Characteristics of Carbopol Gel Containing Nano-size Particles," 2011
  19. Eastman, J. A., Choi, S. U. S., Li, S., Yu, W., and Thompson, L. J., "Anomalously increased effective thermal conductivity of ethyleneglycol-based nanofluids containing copper nanoparticles," Appl. Phys. Lett, Vol. 78, 2001, pp.718-720 https://doi.org/10.1063/1.1341218
  20. Choi, S. U. S., Zhang, Z. G., Yu, W., Lockwood, F. E., and Grulke, E. A., "Anomalous thermal conductivity enhancement in nanotube suspensions," Appl. Phys. Lett., Vol. 79, 2001, pp.2252-2254 https://doi.org/10.1063/1.1408272
  21. Patel, H. E., Das, S. K., and Sundararajan, T., "Thermal conductivities of naked and monolayer protected metal nanoparticle base nanofluids: Manifestation of anomalous enhancement and chemical effects," Appl. Phys. Lett., Vol. 83, 2003, pp. 2931-2933 https://doi.org/10.1063/1.1602578
  22. Jang, S. P. and Choi, S. U. S., "Role of Brownian motion in the enhanced thermal conductivity of nanofluids", Appl. Phys. Lett., Vol. 84, 2004, pp.4316-4318 https://doi.org/10.1063/1.1756684
  23. You, S. M., Kim, J. H., and Kim, K. H., "Effect of nanoparticles on critical heat flux of water in pool boiling heat transfer," Appl. Phys. Lett., Vol. 83, 2003, pp.3374-3376 https://doi.org/10.1063/1.1619206
  24. Fellouah, H., Castelain, C., Ould-El-Moctar, A., and Peerhossaini, H., "The Dean instability in power-law and Bingham fluids in a curved rectangular duct," Journal of Non-Newtonian Fluid Mechanics, Vol. 165, 2010, pp.163-173 https://doi.org/10.1016/j.jnnfm.2009.10.009
  25. Hammad, K. J., Vradis, G. C., and Otugen, M. V., "Laminar Flow of a Herschel-Bulkley Fluid over an Axisymmetric Sudden Expansion," Trans. ASME: J. Fluid Eng. 123, 2001, pp.588-594
  26. Dean, W. R., "Note on the Motion of Fluid in a Curved Pipe," Proc. K. Soc. London Ser, A25, 1927, pp.208-223
  27. Dean, W. R., "The Streamline Motion of Fluid in a Curved Pipe," Philos. Mag., Vol. 30, 1928, pp.673-693
  28. Delplace, F. and Leuliet, J. C., "Generalized Reynolds number for the flow of power law fluids in cylindrical ducts of arbitrary cross-section," Chem. Eng. J. Biochem. Eng. J., Vol. 56, No. 2, 1995, pp.33-37 https://doi.org/10.1016/0923-0467(94)02849-6