كليدواژه :
الگوي الكترواستاتيك ارتقاء‌يافته , شبيه‌سازي عددي , عملگر پلاسماي دي‌بي‌دي , كنترل جريان سيال
چكيده فارسي :
كنترل جريان سيال عبوري از سطوح آيروديناميكي به كمك عملگرهاي پلاسماي دي‌بي‌دي، بسيار مورد توجه قرار گرفته است. ازجمله چالش‌هاي پژوهش در اين زمينه، ضعف الگوهاي عددي است كه بتوانند فيزيك اين پديده را به‌طور دقيق و با هزينه محاسباتي كم شبيه‌سازي كنند. يكي از الگوهاي سريع براي شبيه‌سازي اندركنش اثر عملگر پلاسمايي و جريان سيال، الگوي الكترواستاتيك سوزن و هوانگ است كه با حل معادلات ميدان پتانسيل الكتريكي و غلظت شارژ، اثر عملگر را به صورت نيروهاي حجمي (جمله‌هاي چشمه) به معادلات مومنتوم جريان اضافه مي‌كند. در اين پژوهش، ارتقايي بر اين الگوي الكترواستاتيك پيشنهاد شده كه در آن ارتباطي ميان دو معادله‌ي مستقل پتانسيل الكتريكي و غلظت شارژ توسط يك شرط مرزي براي توزيع شارژ، برقرار مي‌شود. براساس الگوي پيشنهادي، نتايج شبيه‌سازي جت القايي
در جريان سيال روي صفحه تخت با دقت بالايي با نتايج آزمايشگاهي تطابق دارد.
چكيده لاتين :
Recently, active flow control by dielectric barrier discharge (DBD) plasma actuators has been increased. These actuators are known as more efficient, low-cost, without the need of moving parts, low power consumption, small size, low weight, easy installation and without delay in control. All these features have attracted researchers to use this actuator in a variety of cases, such as turbulence flow control, laminar to turbulent transition suppression, separation control, drag reduction and mitigation of noise pollution. However, most of the studies suffer from lack of an accurate numerical model which can simulate this phenomenon in details. Computational analysis of this phenomenon is very complex and difficult due to a combination of ionization phenomena and the interaction of the fluid flow with the actuator effects. For the exact solution of this phenomenon in certain conditions, Maxwell and Navier-Stokes equations must be combined, while this non-linear solution combination will be very difficult. One of the models for modeling the interaction between the actuator and fluid flow is an electrostatic model which adds the actuator effect as source terms in the momentum equations by solving the electrical potential equation and charge density equation. In this study, an improvement is proposed to enhance the simulation accuracy of a model used for plasma actuator effect under interaction with fluid flow. In the modified model suggested, a boundary condition for charge distribution on the charged surface is presented based on a relationship between the independent electrical potential and charge density equations. Further, semi-empirical relations are utilized to calculate the produced plasma extend. The effect of the actuator on induced jet shows a good agreement with experimental results and does not need experimental tests for parametric calibration.
