Isao Teruya

Experimental Study of Effect of Jets Injected into Supersonic Main Flow on Porous Cavity

In this study, the interaction between the supersonic main duct flow and jet surrounded by a porous cavity was experimentally investigated by means of schlieren flow visualization and measurements of flow direction in a cavity underneath of jets. The detection of flow directions was done with so called thermal tuft probe that has two heat sensors and one heat source middle of the two sensors. The parameters of the experiments are jet arrangements and pressure ratio defined by the ratio of total pressure in the settling chamber to atmospheric pressure. As a result, the backward flow in the cavity is confirmed in case of jet injections. Moreover, it is found that the change in the flow direction has dominant frequency between 300HZ and 400Hz only when the starting shock wave exists around the porous cavity

Time‐Serial analysis on Gas‐Liquid Two‐Phase Bubbly Flow using POD

Bubbly flows are complicated flows because bubbles are deformable and the bubble‐bubble interactions work in local area including a lot of bubbles. Such flow occurred turbulence in liquid phase by each bubble is called “pseudo turbulence”. A PIV is most effective to measure complicated bubbly flow because of multi‐dimensional measurement. Recently Dynamic PIV system which is consisted of high‐speed camera and high‐repetition laser is developed, and it is possible to capture time‐serial images with higher resolution. In this paper POD (Proper Orthogonal Decomposition) is described as post‐processing of bubbly flow. We confirmed it has the effect of temporal‐spatio smooth filter.

Flow Visualization on Gas-Liquid Two-Phase Flow with Contraction

This paper described about flow visualization of a gas-liquid two-phase flow in vertical channel with contraction. We have found that the pulsation for void fraction and pressure are occurred by the contraction. However, the mechanism of pulsation is not cleared. Therefore, we visualize the gas-liquid two-phase flow at contraction and the downstream region using high-speed camera system.