Departure-site spacing for liquid columns falling between horizontal circular tubes

The departure-site spacing between liquid columns was measured for water, ethylene glycol, water and ethylene glycol binary mixture with volume fraction 0.5/0.5 on eight different orifice configurations with a visualization method. The influences of flow rate, tube spacing, surface structure and orifice configuration on departure-site spacing were investigated for the subcooled liquid columns flowing between horizontal tubes at the ambient temperature and normal pressure. Under the conditions of this study, the departure-site spacing increases with the decrease of Re for high-Ga flow. For a fixed Re, the departure-site spacing increases with the increase of tube spacing. The surface structure and thermo-physical properties of fluid influence the departure-site spacing. Bigger hole diameter brings smaller departure-site spacing at a fixed distance between adjacent holes, while larger distance between adjacent holes leads to larger departure-site spacing at a fixed hole diameter.