CFD simulation and optimize of LN2 flow inside channels used for cryoge nic machining: application to milling of titani um alloy Ti - 6Al - 4V

Abstract

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 tankto 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 cutting tool/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.