Physical and mathematical modelling of ladle metallurgy operations

Experimental measurements are reported, on the velocity fields and turbulence parameters on a water model of an argon stirred ladle. These velocity measurements are complemented by direct heat transfer measurements, obtained by studying the rate at which ice rods immersed into the system melt, at various locations. The theoretical work undertaken involved the use of the turbulence Navier-Stokes equations in conjunction with the kappa-epsilon model to predict the local velocity fields and the maps of the turbulence parameters. Theoretical predictions were in reasonably good agreement with the experimentally measured velocity fields; the agreement between the predicted and the measured turbulence parameters was less perfect, but still satisfactory. The implications of these findings to the modelling of ladle metallurgical operations are discussed

The turbulent recirculating flow field in a coreless induction furnace. A comparison of theoretical predictions with measurements

A mathematical representation for the electromagnetic force field and the fluid flow field in a coreless induction furnace is presented. The fluid flow field was represented by writing the axisymmetric turbulent Navier-Stokes equation, containing the electromagnetic body force term. The electromagnetic body force field was calculated by using a technique of mutual inductances. The kappa-epsilon model was employed for evaluating the turbulent viscosity and the resultant differential equations were solved numerically. Theoretically predicted velocity fields are in reasonably good agreement with the experimental measurements reported by Hunt and Moore; furthermore, the agreement regarding the turbulent intensities are essentially quantitative. These results indicate that the kappa-epsilon model provides a good engineering representation of the turbulent recirculating flows occurring in induction furnaces. At this stage it is not clear whether the discrepancies between measurements and the predictions, which were not very great in any case, are attributable either to the model or to the measurement techniques employed

The electromagnetic force field, fluid flow field and temperature profiles in levitated metal droplets

A mathematical representation was developed for the electromagnetic force field, the flow field, the temperature field (and for transport controlled kinetics), in a levitation melted metal droplet. The technique of mutual inductances was employed for the calculation of the electromagnetic force field, while the turbulent Navier - Stokes equations and the turbulent convective transport equations were used to represent the fluid flow field, the temperature field and the concentration field. The governing differential equations, written in spherical coordinates, were solved numerically. The computed results were in good agreement with measurements, regarding the lifting force, and the average temperature of the specimen and carburization rates, which were transport controlled

Implementation of a bowel management program in the treatment of incontinence in children for primary healthcare providers

Objectives: Our surgical team has devised a bowel management program (BMP) as a basic approach for primary healthcare providers with the least use of resources.Background: Soiling in children is a major problem that has a serious impact on the child’s social and psychological life. Causes vary from idiopathic constipation to postoperative or neuropathic causes as meningomyelocele.Participants and methods: Seventy five children suffering from fecal incontinence were assessed and divided into true incontinence and pseudoincontinence groups. The BMP was applied to both categories in the form of proper diet control, enemas, drugs, and bowel habit alteration. The program was fashioned according to the age, type, severity, and response of each case. A fecal incontinence scoring system was used to assess the results.Results: All cases with pseudoincontinence attained 50% or more improvement in incontinence score whereas the true incontinence cases attained excellent results except in post high anorectal malformation repairs and neurologic groups.Conclusion: Most of the cases suffering from constipation with pseudoincontinence can be treated properly by BMPs, whereas the minority suffering from true incontinence need multidisciplinary work to achieve acceptable results.Keywords: anorectal malformations, bowel management program, chronic idiopathic constipation, fecal incontinence, Hirschsprung’s disea