Control of Boundary Layer over NACA0015 Using Fuzzy Logic by Suction Technique

تعتبر طريقة اعادة التصاق الجزء المنفصل من الطبقة المتاخمة واحدة من اهم الطرق المستخدمة لتحسين الجريان فوق الاجسام. وقد ركزت هذه الدراسة على تصميم وبناء نظام سيطرة يعمل وفقا للمنطق الضبابي للسيطرة على أنفصال الطبقة المتاخمة من على سطح مقطع جناح طراز ((NACA0015وذلك من خلال التحكم بسرعة محرك جهاز التفريغ الذي يقوم بسحب الجزء المنفصل من الطبقة المتاخمة من خلال خمسة ثقوب موزعة على طول المحور العرضي للجناح وعلى خط يبعد مسافة (75%) من طول الوتر مقاسة من مقدمة المقطع. كل التجارب العملية تم اجرائها في نفق هوائي دون الصوتي ذي مقطع اختبار (300x300x 600) mm وعند قيم رقم ريبنولد وزوايا هجوم مختلفة. واهم النتائج التي تم الحصول عليها هي: ان استخدام نظام سيطرة يعمل وفقا للمنطق الضبابي في السيطرة على تقنية المص سوف يؤدي الى زيادة في قيمة معامل الرفع للجناح (CL) بمقدار (14.72%) عنه في الحالة الاعتيادية كذلك فان قيمة زاوية الانفصال سوف تزداد من 15o الى 17o. ايضا ان استخدام قواعد المنطق الضبابي في برمجة نظام السيطرة اعطى تحسينا مستقرا عند قيم معامل سحب CQ مقبولة.Re-attachment the separation of boundary layer using suction method is one of the important techniques, which improve the flow over bodies. This study focused on the design of fuzzy logic controller to control on the separation of the boundary layer, using suction delayed separation technique from the surface of NACA 0015 airfoil. The airfoil was designed and fabricated depending on the airfoil tool with (300x300) mm chord and span length respectively. The upper surface was developed with five holes  6mm diameter to suck the delayed boundary layer along the span of the airfoil about 75% from leading edge . Also there are four BMP180 Piezoelectric pressure sensors distributed with constant pitch on upper surface of model used to sense the pressure difference. Sub sonic wind tunnel with (300x300x 600) mm work section is used. (1.354, 1.915, 2.345, 2.708 and 3.028 x 105) Reynolds numbers and (0o, 3o, 6o, 9o, 12o, 15o, 16o and 17o) are the angles of attack were used as a conditions boundary of the experimental work. The model was tested without applying suction to determine the stall condition. Pneumatic vacuum cleaner with (0.00737 to 0.01329) discharge coefficient range was used to perform the suction experiment. Pressure difference and angle of attack were input of fuzzy logic controller which programmed by using commercial Matlab softwar. The results of applying suction showed an increase of 14.72% in the lift coefficient and increase the stall angle from 15o to more than 17o. Also lift/drag ratio increased when angle of attack increased. Fuzzy logic rules gave steady enhancement at range of suction coefficient CQ universally acceptable

Analysis of Suspended Vibrated Drum, Part II: Improvement Dynamic Model Using Particle Swarm Optimization

Particle swarm optimization (PSO) algorithm has been used to obtain the optimal design of three degrees of freedom mathematical model for the suspended vibrated drum. Optimization is done for the geometric distance of the model; therefore the mathematical model has two constraints which are presented. The constraints must be achieved to improve the model. PSO code is programmed in MATLAB with exchanging data between MATLAB and Simulink