Overview

Background

In the engineering field, to control liquid or vapor flow is essential to fundamental technology that enables modern living. Internal combustion engine, energy generation by thermal power, passenger and cargo service by automobiles, airplanes, or ships, manufacturing by using fluidization technology in steel or chemical industry: all of these technologies are related to flow control. In this project, we are trying to develop a system that enables to utilize selected functions of flow by adding highly intelligent functions to the fluid itself or its surroundings. Furthermore, we are trying to systemize turbulent flow control technologies and stimulate studies on thermo-fluid dynamics to develop new technologies. Turbulent flow, which is characterized by small eddy motion, plays a key role to the entire flow motion. However, we usually control flow by using macroscopic methods such as operating valves, without elucidating the entire flow mechanism. In these days, technologies such as numerical simulation methods of turbulent flows with TFLOPS (tera floating point operations per second) supercomputer, micromachine technology, and control theories have been developed, which may contribute to the development of microscopic turbulent control method.

Technical Contents

In this project, three national research laboratories above mentioned collaborate under the common research topic. The Executive Manager, who is responsible for research management, and Management Groups, which are responsible for decisionミmaking, are appointed to fulfill the objectives, and every participating researcher is cooperate each other to accomplish the project. The project, which aim at developing and systemizing highly intelligent fluid-dynamic devices with new functions and establish innovative turbulent control systems, consists of the following two subthemes.    Subtheme1: Active control of turbulent flow (AIST, NMRI) This subtheme consists of the following working subgroups. On study for active control of turbulent flows by using micromachine, we are going to develop methods for active control of wall turbulent flow mainly using MEMS (micro electromechanical systems) such as micro sensors, actuators and controllers installed on the wall surface to control the micro-flow near the wall and the entire flow. On study for control of physical property of fluids, we are going to control flows by injecting microbubbles or adding surfactants, which may help to control and utilize microscopic physical properties of fluid selectively.    Subtheme2: Control of turbulent combustion (NAL)  It is said that mankind became civilized when he started to use fire. Almost all kinds of energy that we use in daily life have something to do with combustion. On this study for combustion control, we are going to investigate the relationship between combustion and turbulent flow and develop environmental friendly combustion technologies by controlling combustion field.

Final Goals

Turbulent flow control technology has been considered as a "dream technology" in the field of thermal and fluid dynamics. This project aims at elucidating phenomena of turbulent flow and controlling turbulence by using fluid-dynamic devices with new functions. In addition, we hope to systematize these control methods to establish advanced technologies for practical use. More specifically, we are going to implement the following technologies: active control of flow structure by using micromachine technologies with cutting-edge control theories, active control of physical properties of fluids locally with micro-bubbles, new thermo-fluid control system with flow resistance reduction and high efficiency heat and material transfer through the establishment of complex control of combustion turbulent flow.

Organized Research Combination System

Smart control of turbulence is an interdisciplinary research theme. The purpose of this study, to demonstrate the possibility of smart turbulence control, can be fulfilled by the unique collaboration among the three national laboratories, namely AIST (National Institute of Advanced Insutrial Science and Technology), NMRI (National Maritime Research Institute), and NAL (National Aerospace Laboratory), each of which has been playing a primary role in the R&D studies on micromachine technologies, high-accuracy experimental techniques, advanced numerical simulation of turbulence, respectively. In this project for organized research combination system, we expect the cooperation among the institute will lead to a positive outcome that may not be achieved by a single organization. Moreover, we expect this project to become a leading center of R&D studies and information in this field. We hope it will contribute to stimulate the R&D studies on control of turbulent flow.