Numerical Study on the Flow over a Simplified Vehicle Door Gap – an Old Benchmark Problem Is Revisited

A simplified automobile door gap model, defined at the Third Computational Aeroacoustics (CAA) Workshop on Benchmark Problems (Category 6) was investigated. After a thorough mesh study compressible and incompressible simulations were carried out and various turbulence models were tried. The influence of three dimensional effects and boundary layer thickness effects were examined too. In case of compressible simulations stability problems were encountered with the non-reflective boundary condition of CFX (beta version at the time of the simulations). It was found that for deep cavities incompressible simulations are not applicable. In spite of the diculties a good agreement between measurements and simulations was found when the flow speed was 50m/s. In case of 26.8m/s flow speed it was found that the presence of the upper channel wall, not taken into account by the previous authors simulating this problem plays an important role – a hitherto unexplained peak in the measured spectrum appeared this way in the simulation

Optimum Finger Spacing for Swimmers

The purpose of this study was to investigate the effect of spreading the fingers in human swimming. Two-dimensional CFD simulations were carried out to gain insight into this problem, modelling the fingers by equidistant cylinders. One, two and then four cylinders were studied with varying distance. The effect of the thumb was neglected. The drag coefficients of the individual cylinders in the assembly were then compared with each other and other previously published data. The power spectrum of the drag coefficients and videos of the velocity contours were also examined. The dominant frequency, its subharmonics as well as the qualitative appearance of the flow varied strongly with the finger distance. Contrary to other studies and our expectations, the optimum finger spacing proved to be the zero distance configuration

Planning Sungang-Quingshuihe neighbourhood for a new innovative growth centre of Shenzhen

Shenzhen is one of the most dynamically growing cities in the world with a population of more than 10 million. Situated in the Pearl River Delta (PRD) in China it is in the powerhouse of the global economy. Some decades ago Shenzhen was a small fishing village only, however, after its designation as a Special Economic Zone (SEZ) the city has gone through rapid urbanization and industrial development. Therefore, currently, Shenzhen is one of the leading economic hubs of China, an important gateway of the large Chinese economy, and a sub-provincial administrative centre in the PRD. Sungang-Quingshuihe (SQ) is a neighbourhood of 2.5 square kilometres, in Louhu district in the east of Shenzhen. The landscape system of SQ has been largely destroyed and fragmented by developments. Our main goal is to redesign SQ neighbourhood for an innovative growth centre of Shenzhen. We envisage SQ as a liveable area with new and modern functions for international residents who work in higher education, information communication industry, medical services, R&D facilities of multinational corporations, and research-oriented start-up companies. In order to accomplish this vision it is required to design new transportation system, public buildings, housing, green corridors and parklands