Mathematical modeling of cold cap
The ultimate goal of studies of cold cap behavior in glass melters is to increase the rate of glass processing in an energy-efficient manner. Regrettably, mathematical models, which are ideal tools for assessing the responses of melters to process parameters, have not paid adequate attention to the cold cap. In this study, we consider a cold cap resting on a pool of molten glass from which it receives a steady heat flux while temperature, velocity, and extent of conversion are functions of the position along the vertical coordinate. A one-dimensional mathematical model simulates this process by solving the differential equations for mass and energy balances with appropriate boundary conditions and constitutive relationships for material properties. The sensitivity analyses on the effects of incoming heat fluxes to the cold cap through its lower and upper boundaries show that the cold cap thickness increases as the heat flux from above increases, and decreases as the total heat flux increases. We also discuss the effects of foam, originating from batch reactions and from redox reactions in molten glass, and argue that models must represent the foam layer to achieve a reliable prediction of the melting rate as a function of feed properties and melter conditions.
Effect of Gas Percolation on Melting of Glass Batch
A model was developed to predict the temperature distribution, heat transfer, and melting time during unsteady heating and conversion of batch to glass. Percolation of gas through the blanket of batch and heat absorption during the decomposition of carbonates are accounted for in the model. In the glassmelt, heat was assumed to be transferred by combined conduction and radiation. The model equations were solved numerically using a finite-difference method. The effects of several model parameters were investigated. The results of computations show that percolation of gas through the batch increases the time required to convert the batch to glass. Absorption of heat and release of gas in the batch due to decomposition of carbonates changed the temperature distribution in the batchiglass system and the melting times were affected relatively little as long as the total energy absorbed during the transformation process remained unaltered.
A numerical study on liquid ring motion and fragmentation for the initial process of liquid explosive dispersal
For the explosive dispersal on liquid fuel of FAE technique, the expansion of gaseous detonation products, axisymmetric radial extension and fragmentation of a liquid ring were analyzed, then corresponding models were established. By those models coupled, the numerical simulation on motion and fragmentation of the liquid ring exerted by strong action was carried out. The results computed show that the models established are feasible, and present study can offer initial conditions for the numerical simulation on the process of liquid secondary breakup and gas-liquid mixing.