Flow separation control over airfoils using DBD plasma body force

Abstract

usually the flow behavior is laminar, which is important for control of the flow [2].Methods to flow separation control include active and passive techniques which are based on energy expenditure and controlled by command. Passive separation control techniques generally constitute geometric changes such as vortex generator, slotted flaps/slats, etc. These control elements are effective if the aircraft is operating in a flight regime that is in their design envelope. However, in off-design conditions, passive control elements can have detrimental effects that are often manifested in the form of increased drag [3]. Active separation control techniques have benefits of passive techniques without their disadvantage in off-design conditions. Also, these techniques have the potential to be implemented in a feedback system that can create more benefits in flight efficiency and maneuverability [3].Dielectric barrier discharge (DBD) plasma actuator is one of the active flow control devices that have been successfully used in aerodynamic flow control applications. Thus, considerable researches have been carried out on DBD plasma actuators over the past decade [4]. The examples of aerodynamic flow control applications by DBD plasma actuators include separation control in leading edge [5, 6], trailing edge [3, 7], bluff bodies [8], low pressure turbine blade [9, 10], axial compressor [11], flow control over a hump [12], Stabilizing a laminar boundary layer [13, 14], bluff body induced sound control [15], airfoil lift increasing [16], etc. Special characteristics of DBD plasma actuator over traditional flow control devices include reduction in size, weight and drag, increasing reliability, inexpensiveness, wide frequency bandwidth, rapid on-off capability, no moving parts, low energy consumption, and increasing stealth.The actuator consists of two asymmetrical metal electrodes separated by a dielectric layer, normally kapton, or Abstract The body force effects of plasma origin on the flow over a NACA 0015 airfoil are investigated by numerical simulation. The plasma actuator effect is estimated based on a phenomenological DBD plasma model coupled with 2-dimentional compressible Navier-Stokes equations. The equations are solved using an explicit finite volume method on unstructured grids. The responses of a separated flow field to the effects of a plasma actuator body force in various magnitudes and locations are presented. Also the effects of plasma region dimensions on the flow separation control are studied. It is found that the dimensions of plasma region, the magnitude of the body force, and the location of the plasma actuator all have significant impacts on the separation control.

Investigation of a Dielectric Barrier Discharge Plasma Actuator to Control Turbulent Boundary Layer Separation

“…The Navier-Stokes equations typically consist of the conservation mass, momentum, and energy. The current work was solely dedicated to capturing the complex physics of the incompressible turbulent flow separation with and without a plasma actuator; however, we neglected the temperature rise due to the plasma as it was considered to be very low and thus ignored [24,25]. In our computations, only the continuity and the momentum equations were considered, where the DBD plasma actuator was modeled as the source term in the momentum equation.…”

“…Additional studies, such as Suzen et al [19], studied on the effect of a DBD plasma actuator on PAK-Bblade flow separation and a low-pressure turbine flow with large flow separation in a quiescent environment [20]. Khoshkoo et al [24] and Gaitonde et al [25] studied DBD actuators to control flow separation over a NACA 0015 airfoil at a high angle-of-attack, showing the ability of phenomenological DBD actuator models to control low-speed flow. Yu et al [26] studied a DBD plasma actuator model with a correction factor to examine the complex flow structure.…”

“…Hasan et al [32], Lu et al [33], He et al [34], and others studied the effects of DBD plasma actuators on the NASA hump model. The Shyy model, proposed by Wei Shyy, was adapted for use in this work due to the reasonable accuracy, low computational cost, and simple implementation [24]. The details of this model are presented in the Computational Methodology Section.…”

Numerical Simulation of Flow Separation Control using Multiple DBD Plasma Actuators

“…4compared with thethree-Dimensional LES numerical simulation results (Kaneda and Asada 2011).In this case the flow separation is initiated at approximately 2%of the chord length from the leading edge. More details can be found in Khoshkhoo and Jahangirian (2014).…”

“…It is appropriate location to place the first actuator. More details can be found in Khoshkhoo and Jahangirian (2014). The second actuator is placed in different locations that are shown Fig.…”