ONSET OF FREEZING IN A THIN WATER TUBE COOLED BY AIR FLOW WITH FALL AND RISE IN TEMPERATURE
The 3-D freezing of water in a vertical thin tube is investigated for air flow cooling by changing temperature in a sine function including the minimum temperature Air flows normal to the tube axis. Sevearal parameters of the air flow inlet temperature (including the minimum temperature the initial water temperature and the period of one cycle of air flow temperature P) and the air flow inlet velocity which are selected in winter seasons actually encountered. After temperature of water decreases gradually, ice appears and develops to the maximum thickness. Ice melts soon from the tube wall, and eventually melts out. A diagram indicating the onset of freezing is presented for a useful knowledge to prevent the freezing of water in a closed tube. Indeed, the minimum temperature of is a dangerous critical to appear ice without regard to and P in the present parameter’s ranges of and
3-D freezing of water, air-flow, dangerous critical.