High-performance computing-based exploration of flow control with micro devices

Abstract

One contribution of 13 to a Theme Issue 'Aerodynamics, computers and the environment' . Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Yoshinodai, Chuo-ku, Sagamihara 252-5210, JapanThe dielectric barrier discharge (DBD) plasma actuator that controls flow separation is one of the promising technologies to realize energy savings and noise reduction of fluid dynamic systems. However, the mechanism for controlling flow separation is not clearly defined, and this lack of knowledge prevents practical use of this technology. Therefore, large-scale computations for the study of the DBD plasma actuator have been conducted using the Japanese Petaflops supercomputer 'K' for three different Reynolds numbers. Numbers of new findings on the control of flow separation by the DBD plasma actuator have been obtained from the simulations, and some of them are presented in this study. Knowledge of suitable device parameters is also obtained. The DBD plasma actuator is clearly shown to be very effective for controlling flow separation at a Reynolds number of around 10 5 , and several times larger lift-to-drag ratio can be achieved at higher angles of attack after stall. For higher Reynolds numbers, separated flow is partially controlled. Flow analysis shows key features towards better control. DBD plasma actuators are a promising technology, which could reduce fuel consumption and contribute to a green environment by achieving high aerodynamic performance. The knowledge described above can be obtained only with high-end computers such as the supercomputer 'K'.

Theoretical modeling of pulse discharge cycle in dielectric barrier discharge plasma actuator

“…A burst mode actuation with duty cycles has possibilities of separation control with a lower input energy. 5,6) The burst wave consists of a highfrequency base wave and a low-frequency burst component, and several experiments presented the control capability of the flow separation when an appropriate burst frequency is applied. 7) The DBD-PA is conventionally used to induce an ionic wind as a momentum source for the main flow, while a nanosecond pulsed DBD-PA (NSDBD-PA) has recently been proposed as an impulse source.…”

Investigation on performance characteristics of dielectric discharge plasma actuator using pulsed-dc waveform

“…DBDPA has many advantages over conventional devices such as no-moving mechanical parts and active controllability by electrical signal. Therefore, many engineering applications of DBDPA to fluidic devices are expected; flow separation control over an airfoil (Corke et al, 2009, Fujii, 2014, a wind turbine (Matsuda et al, 2017) and so on. However, the control effect decreases in higher Reynolds number flow (higher mainstream velocity) because the flow speed of the induced jet is typically only up to several meters per second.…”

Aerodynamics, computers and the environment

“…Fujii [13], at the Japanese Aerospace Exploration Agency, gives a positive aerospace perspective for the use of NDS to explore flow control. The paper focuses on plasma actuators and their use on high liftconfigured aerofoils.…”