Computational Study of Impingement Characteristics of Assist Gas from Coaxial/Off-axis Nozzles in Laser Machining

레이저 가공에서 동축/탈축 보조가스의 충돌특성에 관한 수치해석적 연구

  • 윤시경 (한국항공대학교(원) 항공우주 및 기계공학과) ;
  • 성홍계 (한국항공대학교 항공우주 및 기계공학부) ;
  • 이열 (한국항공대학교 항공우주 및 기계공학부)
  • Received : 2010.07.19
  • Accepted : 2010.09.09
  • Published : 2010.10.30

Abstract

A computational study was carried out to analyze the characteristics of supersonic (Mach 2.0) coaxial/off-axis jet's impingements on a slanted kerf surface in laser machining. The effects of various parameters such as gas pressure, distance between nozzle exit and kerf edge surface, and application of off-axis nozzles on the impingement phenomena of the assist-gas on kerf surface were observed. The present study showed that simply increasing the assist-gas pressure for coaxial supersonic nozzle was not effective to alleviate the strength of flow separation on kerf surface. It also presented the optimized operating condition of the coaxial nozzle to have the highest skin friction values over kerf surface.

Keywords

References

  1. Fieret, J., Terry, M. J., Ward, B. A., "Overview of flow dynamics in gas-assisted laser cutting," SPIE High Power Lasers, Vol. 801, pp. 243-250. 1987
  2. 방세윤, 한유희,"레이저 절단에서의 노즐 및 가스제트의 영향," 대한용접학회지, 제12권, 제2호, pp. 1-10. 1994
  3. Man, H. C. et al., "Analysis of the dynamic characteristics of has flow inside a laser cut kerf under high cut-assit gas pressure," J. Phys. D: Appl. Phys., Vol. 32, pp. 1467-1477. 2000
  4. Fieret, J., Rand, C., "Cutting thin steel sheet," Industral Laser Solutions, Feb., wwwe.industrial-laser.com, 2007
  5. Duan, J., Man, H. C., Yue, T. M., "Modelling the laser fusion cutting process: Effect of various process parameters on cut kerf quality," J. Physics D: Appl. Phys. 34, pp. 2143-2150. 2001 https://doi.org/10.1088/0022-3727/34/14/310
  6. Kovalev, O. B., Yudin, P. V., Zaitsev, A. V., "Modeling of flow seperation of assist gas as applied to laser cutting of thick sheet metal," Applied Mathematical Modelling, Vol. 33, pp. 3730-3745, 2009 https://doi.org/10.1016/j.apm.2008.12.011
  7. Quintero, F. et al, "Comparative study of the influence of the gas injection system on Nd:yttrium-aluminium-garnet laser cutting of advanced oxide ceramics," Rev. Sci. Instrum., Vol. 74, No. 9, pp. 4199-4205, 2003 https://doi.org/10.1063/1.1597953
  8. Heo, J. Y. et al, " Fluidic Thrust Vector Control of Supersonic Jet Using Co-flow Injection ", 45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, AIAA 2009-5174, 2009
  9. Yang, Z., Shih, T. H., "New Time Scale Based Model for Near Wall Turbulence," AIAA Journal, Vol. 31, pp. 1191-1197, 1993 https://doi.org/10.2514/3.11752
  10. 손상혁, 민성규, 이 열, "레이저 절단에서 나타나는 보조가스의 절단면 충돌유동 가시화," 한국기계가공학회 2010년도 춘계학술대회논문집, 2010