The text discusses the growth of vapor bubbles in superheated liquids, focusing on the factors controlling this process: liquid inertia, surface tension, and vapor pressure. As the bubble grows, evaporation occurs at its boundary, reducing the temperature and vapor pressure inside. The heat required for evaporation depends on the bubble's growth rate, linking the dynamic and heat diffusion problems. A solution for the bubble's radius as a function of time is derived, valid for large radii, and shows the significant effect of heat diffusion on growth rate. Experimental observations in superheated water show good agreement with the theoretical predictions.
The physical model assumes a spherical vapor bubble with uniform temperature and pressure, neglecting viscosity and compressibility effects. The equation of motion for the bubble radius is derived, incorporating the pressure difference between the bubble and the surrounding liquid. The pressure inside the bubble is given by the equilibrium vapor pressure minus a term related to surface tension.
The solution for the bubble's radius is analyzed for large radii, showing that the growth rate depends on the balance between surface tension and heat diffusion. The analysis includes the cooling effect of evaporation, which significantly influences the bubble's growth. The temperature at the bubble wall is determined by the heat conduction from the liquid into the bubble, leading to a temperature gradient that affects the bubble's growth.
The solution is compared with experimental observations, showing good agreement. The growth behavior is analyzed for large radii, where the bubble's radius increases steadily, but the temperature at the bubble wall cannot fall below the boiling temperature of the liquid. The asymptotic solution for the bubble's radius is derived, showing that the growth rate depends on the balance between surface tension and heat diffusion. The analysis also includes the effects of initial conditions and the delay period in bubble growth, which is accounted for by shifting the asymptotic solution in time. The results are consistent with experimental observations, confirming the validity of the theoretical model.The text discusses the growth of vapor bubbles in superheated liquids, focusing on the factors controlling this process: liquid inertia, surface tension, and vapor pressure. As the bubble grows, evaporation occurs at its boundary, reducing the temperature and vapor pressure inside. The heat required for evaporation depends on the bubble's growth rate, linking the dynamic and heat diffusion problems. A solution for the bubble's radius as a function of time is derived, valid for large radii, and shows the significant effect of heat diffusion on growth rate. Experimental observations in superheated water show good agreement with the theoretical predictions.
The physical model assumes a spherical vapor bubble with uniform temperature and pressure, neglecting viscosity and compressibility effects. The equation of motion for the bubble radius is derived, incorporating the pressure difference between the bubble and the surrounding liquid. The pressure inside the bubble is given by the equilibrium vapor pressure minus a term related to surface tension.
The solution for the bubble's radius is analyzed for large radii, showing that the growth rate depends on the balance between surface tension and heat diffusion. The analysis includes the cooling effect of evaporation, which significantly influences the bubble's growth. The temperature at the bubble wall is determined by the heat conduction from the liquid into the bubble, leading to a temperature gradient that affects the bubble's growth.
The solution is compared with experimental observations, showing good agreement. The growth behavior is analyzed for large radii, where the bubble's radius increases steadily, but the temperature at the bubble wall cannot fall below the boiling temperature of the liquid. The asymptotic solution for the bubble's radius is derived, showing that the growth rate depends on the balance between surface tension and heat diffusion. The analysis also includes the effects of initial conditions and the delay period in bubble growth, which is accounted for by shifting the asymptotic solution in time. The results are consistent with experimental observations, confirming the validity of the theoretical model.