MEASUREMENT AND FLOW VISUALIZATION STRATEGY FOR WIND TUNNEL EXPERIMENTS: AN AIRFOIL LIFT DEMONSTRATION APPARATUS FOR UPPER SECONDARY LEVEL

• Main Author: Mayo Aquino Pang, Ignatius
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/62637
• Institution: Institut Teknologi Bandung

The complexity of the mathematical language in the Kutta-Joukowski theorem encourages Physics teachers to use another, simpler concept to explain lift, namely the Bernoulli Principle. A set of demonstration apparatus (wind tunnel, mist maker, modified inclined U manometer) has been made, and a series of experiments have been carried out to prevent possible misconceptions. Even though the apparatus is spacious and the manufacturing process is complicated, a wind tunnel is still needed; hence airflow visualization using a particle tracer (ultrasonic nebulizer technique) can be carried out accurately. Airflow visualization is mainly used to demonstrate the airflow around the trailing edge of the NACA 4412 airfoil. With an airflow visualization, lift can be explained by Newton's 3rd Law. In our experiment, lift was indicated by pressure difference (PB - PA). The pressure difference measurement utilizing digital video analysis method that has never been applied to the wind tunnel experiment nor the pressure difference measurement. Utilizing Tracker, the resolution of pressure difference measurement and the airspeed measurement uncertainty can reach 10,5 mPa and 4 mm/s. Moreover, airflow visualization demonstrates laminar and turbulent flow, Coanda effect, and describes the effect of the curvature of the airfoil surface on the pressure difference. Thus, when used in Fluid Dynamic class, this apparatus and the experiments can enhance the accuracy of learning, particularly airfoil lift at the upper secondary level, based on the concept of Newton's 3rd Law.