Tetsuro Tsujimoto

Distorted Model and Time Scale Evaluation of Multiscale Subjected Fluvial Processes

Fluvial process is often subjected to several different factors and thus a physical model test, which satisfies all requisite similarity criteria, is difficult to plan. Sometimes a distorted model is required and the detailed arrangements for the requisite conditions are particularly difficult to meet. With a physically reasonable analytical model, we could skillfully predict prototype behavior from partially imperfect distorted model. By taking an example in predicting scour depth around a bridge, this study demonstrated how an analytical model can be used effectively to complement a physical model study.

SEDIMENT-CLOUD BASED MODEL OF SUSPENSION OVER RIPPLE BED DUE TO WAVE ACTION

A special reflecting wall 12 m long and 2.1 m high was built off the beach at Reggio Calabria, and 30 wave gauges were assembled before the wall and were connected to an electronic station on land. It was possible to observe the reflection of wind waves generated by a very stable wind over a fetch of 10 Km. The experiment aimed to verify the general closed solution for the wave group mechanics (Boccotti, 1988, 1989), for the special case of the wave reflection.Significant features on Wadden Sea wave climate are evaluated in respect of the state of the art. Main emphasis was laid on an analysis of the governing boundary conditions of local wave climate in island sheltered Wadden Sea areas with extensions being sufficient for local wind wave growth. Explanatory for significant wave heights a reliable parametrization of local wave climate has been evaluated by using generally available data of water level and wind measurements.

Momentum Exchange between Fluid and Particles and Mutual Collisions among Particles in Saltation Layer

In order to make a general model for granular material transport in saltation motion by fluid, (i) collision and rebounding of saltating particles at the bed; (ii) interaction between fluid and particles; and (iii) mutual collisions among saltating particles are investigated.