Abstract
Physical model experiments as well as numerical simulations are widely carried out to estimate flow phenomena of high-temperature liquid flow because it is difficult to observe or measure the high-temperature liquid flow directly. As for the physical modelling, similitude is an essential matter that has a great influence on the representation of real flow phenomena in the prototype. A commonsense of the physical modelling had been satisfying the similitude of one or two dimensionless numbers considering dominant forces influence on the objective flow phenomena. In this paper, physical modelling conditions required for the simultaneous similitude of multiple dimensionless numbers (SMDN) has been studied to enhance the accuracy of the flow phenomena representation. As a result, a simple relationship between physical properties of fluids and scale ratio of the physical model has become clear for the simultaneous similitude of the Froude, Reynolds, Galilei, capillary, Weber, Eötvös and Morton numbers. Then, rising velocity of bubbles has been investigated obtaining a result that the relative rising time of bubbles in the physical model corresponds well with that of the prototype under the SMDN condition. This result indicates physical models that satisfy the SMDN condition precisely represent flow phenomena of gas-liquid systems influenced by four forces; inertial force, gravitational force, viscous force and surface tension force, including bubble rising behavior as well as the bulk flow phenomena.
