This paper explains three important factors of fluid dynamics in sports through the analysis of flight in a ski jump. The first important element is measuring aerodynamic forces in wind tunnel tests. If the values of aerodynamic forces are not accurate, the results of the computer simulation may be invalid. The second influence is concurrent optimization. Fluid dynamics research for sports should consider not only one objective, but several objectives in order to ensure equal optimization. The final factor is translating feeling to a quantity which can be simulated. This is attained on the basis of careful observation and insight for each problem.

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  The wind tunnels used for full size cars are explained. The main specifications, maximum air speed, test section dimension, test section types, and wall interference are discussed first. Especially, the effect of adaptive wall test section is introduced. Five-belt moving belt system is shown with some examples next, which is the best ground simulation and most suitable for the cars. Finally, low noise wind tunnels and the improvement of conventional wind tunnels to the low noise type are written. Low noise wind tunnels are very popular today, because they are useful to decrease the wind noise of the cars.

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  The competition in the aerodynamics development in the wind tunnel between F1 teams has been heating up in the last decade, which requires extremely accurate and repeatable results. In addition, its development pace is extremely rapid in order to catch up with the race schedule, in which the race takes place at least twice a month during the season. It means that the process of the wind-tunnel development must be highly efficient so that the track performance of the F1 machine should improve every race by aerodynamic updates. In this paper, some unique technologies are described in detail, by looking back the history of the F1 development at Toyota Motorsport GmbH (TMG). It includes the wind tunnel measurement system, the detail scale-model, F1's first PIV system, and other activities to improve the model configurations and experimental conditions to match the real world.

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  Since the first powered flight by Wright brothers, wind tunnel has been one of key ground test facilities required for development of aircraft and space vehicles. In Japan, large-scale industrial wind tunnels were developed and have been operated by Japan Aerospace Exploration Agency, JAXA. To keep and increase the capabilities of the tunnels, maintenance of the facilities and research and development on advanced testing and measurement technologies were being done continuously. In this article, four major industrial wind tunnels in JAXA covering low to hypersonic speed ranges are introduced with new aerothermodynamic/aeroacoustic measurement techniques such as pressure-sensitive paint (PSP), particle image velocimetry (PIV), CT-reconstructed schlieren imaging, and microphone-array technique. Also, described are activities to improve data accuracy and data productivity as well as data uncertainty analysis. Finally, as an activity towards future integration between experimental fluid dynamics (EFD) and computational fluid dynamics (CFD), development of ‘Digital/Analogue-Hybrid Wind Tunnel’ which is under way is presented.

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  The RTRI's Large-Scale Low Noise Wind Tunnel located in Maibara-shi in Shiga Prefecture, Japan, is a unique railway wind tunnel built for the purpose of studying aeroacoustic and aerodynamic phenomena for high-speed trains. This wind tunnel has following features:
/Extremely low background noise enables measurement of the aerodynamic noise generated from a model with remarkable accuracy.
/The test section is long enough to allow wind tunnel tests for a train-set model composed of multiple cars.
/The wind tunnel has boundary layer suctions and a large and high speed moving belt. These enable simulation of flow between the model and the ground with considerable reality. This will be helpful for conducting research on decreasing the aerodynamic drag and improving the aerodynamic characteristics of high-speed trains.
This wind tunnel can be used for not only railways but also automobile and others.

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