Tim Evans

Basic oxygen furnace (BOF) is a key steelmaking process for yielding qualified liquid metal by removing the harmful elements sourced from the iron ore, and it features complex multiphase flow, especially the cavity, the key region strongly governing the smelting and refining. However, the understanding of the dynamic cavity characteristics, especially the periodic features within an industrial-scale BOF, remains limited. In this study, an industrial-scale BOF model is developed based on computational fluid dynamics (CFD), considering the system's multiphase nature and interactions, to quantify long-term cavity dynamics and the related periodic features. The results show that the mathematical model effectively captures the multiphase flow features inside and around the cavity. The cavity profiles, particularly, depth and radius grow significantly between 0.1 s and 0.4 s before reaching a less unsteady state. Subsequently, the cavity geometric features, including depth, radius, volume, and interfacial area, maintain distinct oscillatory behaviours over time. The time-averaged values for cavity volume, interfacial area, depth, radius, and sphericity are 0.31 m ³ , 1.95 m ² , 0.78 m, 0.55 m, and 0.76, respectively. Furthermore, cavity depth exhibits more pronounced periodic features than other cavity properties, with the primary period being approximately 1 s for the studied scenario. This study may provide valuable insights into the further understanding and optimisation of multiphase flow behaviours within an industrial-scale BOF.

A problem associated with gas injection into molten metal through tuyeres is the accelerated erosion of refractory lining due to a back attack phenomenon caused by pressure and liquid velocity fluctuations impinging on the refractory surface. Back attack is closely linked to the gas conditions at tuyere exit, and in this study a computational (CFX-F3D) model has been used to predict the radial velocity, density and temperature profiles for gas flow exiting a circular tuyere into a molten metal bath. It was found that both the adiabatic and non-adiabatic models predicted a deficit in the mass flux and dynamic pressure in the body of fluid adjacent to the tuyere wall when compared with fluid in the centre of the tuyere. The deficit at the walls is used to explain, qualitatively, the back-attack phenomenon.

Observations of middle aged to retired clients in Personal Training practices in London UK, surfaced two themes; exercise-averse individuals with sedentary leisure and work pursuits reported poor experiences of physical education in secondary (high) school, whereas more active clients reported positive reflections. This instigated a systematic examination of contemporaneous documents and literature, which sought to explain the context of this reality. Five major themes emerged: The politico-educational environment from the 1960’s to the 1970’s, the parallel experience of maths anxiety, teaching practice, navigating failure and economic implications. Evidence suggests why the behaviour of a generation has been impacted; a post-war hierarchical social order undergoing profound change, poor pedagogic practices in which the less able found themselves suffering everything from corporal punishment to physical embarrassment and response models to failure predict clients’ later behaviours. The research findings substantiate the claims of clients’ memories of negative experiences with physical education at secondary school. The research concludes that the socio-economic costs associated with such past failures in PE are estimated to exceed £6 billion over the life of a contemporary five-year UK government and have clear social and economic implications for other developed democracies.