Hiromori Miyagi

An Actively Controlled Wind Tunnel And Its Application To The Reproduction Of The Atmospheric Boundary Layer

An actively controlled wind tunnel equipped with multiple fansand airfoils has been developed, mainly for the purpose of reproducing the atmospheric boundary layer (ABL) for wind engineering applications. Various fluctuating flows can be achieved in this wind tunnel by altering the input data of the fans and airfoils through computer control. In this study, the ABL is physically simulated in this wind tunnel, and particular attention ispaid to the simulation of the profile of Reynolds stress. The method of generating the fluctuating flow and the experimental results of reproducing the ABL are presented. As the results show, the spatial distribution of Reynolds stress is satisfactorily simulated, and the profiles of other statisticalturbulent parameters, such as mean velocity, turbulent intensity, integral scale and power spectrum are successfully reproduced simultaneously.

High-Strength Porous Ceramics Produced by Recycling Glass Fibers in Waste GFRP

Ceramics, Composite Material, GFRP, Clay, Recycling, Bending strength Abstract In this study, as the effective recycling technique for the waste GFRP, the process for the producing the porous glass fiber reinforced ceramics by firing the mixture of the clay and the crushed waste GFRP was proposed. The proposed recycling technique for the waste GFRP enables to produce various ceramics parts by effectively reusing the glass fibers included in the waste GFRP as well as to dispose injurious GFRP radically. By changing the mixing ratio of the waste GFRP and clay, and by firing the mixture at some temperatures, several kinds of ceramics specimens (tiles) were produced. The microstructure of each specimen was observed using the SEM and the microscope, and then water absorption and the bending strength of the specimens were examined in detail by comparison with those of specimens without the glass fiber. From those results, it was confirmed that the high-strength porous glass fiber reinforced ceramics could be produced by our proposed process.

Development of a Large-Scale Wind Tunnel of Multi-Fan Type (Characteristics of Turbulent Flow by a Uniformly-Active Method)

In an attempt to simulate both large scale and high-intensity turbulence within a limited entry length, an innovative wind tunnel of “multi-fan type” is developed. The airflow is driven by an array of fans (9 columns×11 rows), each of which is independently controlled by a computer. Details of the wind tunnel were introduced, and two typical methods (“uniformly-active” and “quasi-grid” methods) were applied to drive the wind tunnel. Comparison with the quasi-grid method revealed the spatial structure of the turbulent flow generated by the uniformly-active method.