The effect of scaling cross section of pipe down with generating microbubble on reducing pipe friction loss

Recently, there are many studies about pipe friction loss because almost energy loss with fluid transportation is ruled in pipe friction at very long fluid circuit such as oil pipeline, water and sewage and so on. There are many methods used to reduce pipe friction loss but there are problems. Therefore, we focused on Microbubbles (MB) MB which has various characteristics such as reducing pipe friction loss, self-pressurizing and so on. On the other hands, MB becomes small with time and disappear in water so we have to provide MB in the middle flow channel to get the effect reducing pipe friction loss. The purpose of this paper is measured pipe friction loss when generated MB by using orifice plate and injected air and flow characteristics. As a result, pipe friction loss decreased when orifice plate is set. Also, the reduction rate of pipe friction loss is decrease when the Re increased. Also, we confirmed bubbles are collapsed when a pipe was injected air but its diameter was bigger than theoretical diameter.