Session: 07-01-01 Aerospace

Paper Number: 65728

Start Time: August 10th, 10:50 AM

65728 - Influence of Exposed Electrode Thickness on Plasma Actuators Performance for Coupled Deicing and Flow Control Applications 

Dielectric Barrier Discharge (DBD) plasma actuators are a popular topic of research within the active flow control field. Several authors have studied these devices during the last twenty years considering their flow control applications. These devices present several interesting features such as the absence of mechanical components, fast response time, very low mass, easy implementation and robustness. However, it has been shown that a big percentage of the power applied to these electronic devices it is not transferred to the adjacent flow but instead dissipated as heat. Studies have shown that the power dissipated by a plasma actuator is composed of the power dissipated by the plasma discharge and the thermal dielectric losses which are dependent on the frequency and applied voltage. Also, due to the plasma actuation the actuator surface may reach temperatures near hundred Celsius degree. On the other hand, we know that in icing conditions, water droplets condensing on a wing's leading edge can freeze and the ice accumulation leads to weight increase and aerodynamic imbalances. When ice starts to accumulate on the aircraft, the growth of the ice disturbs the local airflow, adds weight and modifies the aerodynamic performance of the surfaces by changing either their shape and/or their surface characteristics. This may lead to a performance decrease, boundary layer airflow disturbance, critical loss of control or lift, premature aerodynamic stall and increase in drag.  Considering the need of good ice prevention systems and the abilities of plasma actuators to dissipate energy in the form of heat, recently plasma actuators started to be studied as devices that can be used to prevent ice formation and at the same manipulate the flow field. This makes a perfect combination not only for aircraft applications but also for wind turbines that operate in cold regions. Studies have shown that the exposed electrode plays an important role on the surface temperature field of the plasma actuator. Thus, in the current study, by the first time, we will investigate the influence of the exposed electrode thickness on the induced velocity flow field and surface temperature field. Our preliminary results indicate that the use of thicker exposed electrodes improve the conductivity of the heat on the exposed electrode region which leads to an of temperatures on the exposed electrode area. By this, the heat dissipation to the adjacent medium will be increased and the plasma actuator device will be optimized as a de-icing and flow control device. Actuators with different dielectric thicknesses and different exposed electrode thicknesses will be experimentally characterized in terms of electrical characteristics, induced flow velocity, mechanical efficiency (which is directly related with the flow control ability) and surface temperature field. It will be shown that the use of thicker exposed electrodes allows to increase the surface temperature and also the surface area affected by the plasma thermal effects which will lead to a considerable improvement of the device performance for coupled de-icing and flow control applications.

Presenting Author: Frederico Rodrigues Universidade da Beira Interior

Authors:

Frederico Rodrigues Universidade da Beira Interior
Mahdi Abdollahzadeh Universidade da Beira Interior
Jose Pascoa Universidade da Beira Interior
Luis Pires Universidade da Beira Interior