CFD simulation and optimize of LN2 flow inside channels used for cryogenic machining: application to milling of titanium alloy Ti-6Al-4V

Cryogenic machining is seen as a possible solution to increase tool life and improve surface integrity of machined components, by efficiently removing the heat from the cutting zone. Unfortunately, most of the publications on this topic does not investigate properly the physical phenomena occurring inside the pipe connecting the tank to the cutting tools/nozzle. These phenomena will affect the cryogenic flow characteristics at nozzle outlet, thus the performance of the cryogenic machining. In this work, a CFD model is developed and applied to investigate the liquid nitrogen (LN2) flow inside the pipe connecting the reservoir to the cuttingtool/nozzle. The results show that the effectiveness of the cooling process depends not only on the input flow parameters ( pressure, velocity, temperature and gas/liquid fraction), but also on the pipe geometry. (C) 2017 The Authors. Published by Elsevier B.V.