The accuracy of computational fluid dynamics analysis of the passive drag of a male swimmer

The aim of this study was to build an accurate computer-based model to study the water flow and drag force characteristics around and acting upon the human body while in a submerged streamlined position. Comparisons of total drag force were performed between an actual swimmer, a virtual computational fluid dynamics (CFD) model of the swimmer, and an actual mannequin based on the virtual model. Drag forces were determined for velocities between 1.5 m/s and 2.25 m/s (representative of the velocities demonstrated in elite competition). The drag forces calculated from the virtual model using CFD were found to be within 4% of the experimentally determined values for the mannequin. The mannequin drag was found to be 18% less than the drag of the swimmer at each velocity examined. This study has determined the accuracy of using CFD for the analysis of the hydrodynamics of swimming and has allowed for the improved understanding of the relative contributions of various forms of drag to the total drag force experienced by submerged swimmers.     

替代性世界：学习环境新方向

教育领域一直以评价和采用交互创新技术为先驱,这些交互创新技术为教育技术专家探索计算机辅助的教学提供了实践的土壤＂。替代性世界＂（Alternative worlds）是完全实时的、高保真的、用户高度介入的学习环境。其特点是具有丰富的环境、丰富的接口、操作驱动和有效应用于教与学＂。替代性世界＂在混合式学习中可以冲破传统教育屏障,拓展教师和学习者角色,为学习者提供时间和空间的便利,实现终身学习＂。替代性世界＂学习环境是一个新的研究领域,它为专注于人机交互、社会网络和虚拟现实的教育技术专家开拓了新方向和新空间。     

Sports History: Reflections on My Journey So Far

Abstract

In this article, I reflect on my journey into sports history and my career path so far. I also discuss my experiences as part of the British Society of Sports History.     

The effects of three school psychological consultation modes on selected teacher and pupil outcomes

Six Kansas school psychologists structured their teacher consultation in terms of three consultative modes which varied primarily in the number of follow-up contacts. The findings indicated that follow-up contacts led to greater teacher implementation of recommendations, greater perceived pupil behavior improvement, and greater sense of cooperative planning by the teachers. These outcome differences occurred between follow-up contacts and no follow-up contacts, with outcome differences not occurring between more and less extensive contacts.