Experimental Study of Transient-State Characteristics of Temperature in the Density Lock

Through the method of visible observation, experimental study on transient-state characteristics of temperature on the interface of stratified fluids is made in three different experimental tubes. On the basis of experimental study, mechanism of temperature oscillation and heat transfer behaviors on the interface of stratified fluids are analyzed under transient-state conditions in the density lock. The results show that the temperature of work fluid near the interface has two kinds of instabilities—high amplitude oscillation and low amplitude oscillation. High amplitude oscillation results from the consequent breaking of the interface and will bring vigorous heat transfer between stratified fluids. After the high amplitude oscillation takes place, temperature jump of work fluid will arise on the interface. However, low amplitude oscillation is only dynamic wave of interface around its balanced position, and it will not cause vigorous heat transfer. Besides, comparative experiment on transient-state characteristics of temperature is done in experimental pipes with different diameters, the results show that high amplitude oscillation is more likely to take place in experimental pipes with larger diameters. Therefore, by virtue of its small diameters, honey-comb channel in density lock can curb the occurrence of high amplitude oscillation, efficiently decreasing heat transfer between stratified fluids.