Numerical modeling and Schlieren visualization of the gas-assisted laser cutting under various operating stagnation pressures

0519170 - ÚPT 2021 RIV US eng J - Článek v odborném periodiku
Darwish, M. - Mrňa, Libor - Orazi, L. - Reggiani, B.
Numerical modeling and Schlieren visualization of the gas-assisted laser cutting under various operating stagnation pressures.
International Journal of Heat and Mass Transfer. Roč. 147, FEB (2020), č. článku 118965. ISSN 0017-9310. E-ISSN 1879-2189
Institucionální podpora: RVO:68081731
Klíčová slova: gas-assisted laser cutting * openFOAM * over-expansion * schlieren visualization * supersonic nozzles * under-expansion
Obor OECD: Fluids and plasma physics (including surface physics)
Impakt faktor: 5.584, rok: 2020
Způsob publikování: Omezený přístup
https://www.sciencedirect.com/science/article/abs/pii/S0017931019339663

The uniformity of the exit jet pattern in high pressure gas-assisted laser cutting represents the main feature in order to achieve high cutting quality and capability. Therefore, the effect of both inlet stagnation pressure and nozzle geometry on the behavior of the exit jet has been investigated in this research. Quasi 1-D gas dynamics theory has been used to calculate the exact-design operating conditions for three different supersonic nozzles that were fabricated by means of Wire Electrical Discharge Machining. The jet flow through these nozzles has been numerically modeled and experimentally checked, using Schlieren visualization, under exact-design, over-expansion and under-expansion operating conditions coming to a good numerical-experimental agreement in terms of flow structure. As main result, the exit jet was found to preserve its uniform distribution with parallel boundaries and low divergence under the exact-design operating condition, differently to what observed for the others two conditions, especially for nozzle with small divergence angle.
Trvalý link: http://hdl.handle.net/11104/0308700