Numerical Study on Spreading and Vaporization Process of Liquid Nitrogen Droplet Impinging on Heated Wall

Micro-structured surfaces can affect heat transfer mechanisms because of enlarged specific surface areas. However, employing the Leidenfrost effect during liquid nitrogen (LN2) droplet cooling a heated micro-structured possessing fin with spacing much smaller than diameter has not yet been explored. In present work, direct numerical simulation (DNS) is carried out to investigate LN2 droplet, whose sufficiently larger structured fin, impinging on variable velocities. For comparative study, smooth also employed in simulations. The spreading and vaporization behavior along film morphology at various conditions are investigated. Results show that size inhibits entering into grooves between fins left untouched by completely, eventually, thinner spread contrast surface. Notably, low Weber number, be shrunk or even rebounded away from wall after wall. fastest for both surfaces, namely micro-structured, obtained number 180. Additionally, an effective upon observed velocity droplet.