Estudo do coeficiente de pressão no escoamento sobre um cilindro de acrílico

Abstract

The flow of fluids on solid bodies happens daily, from which several physical phenomena occur, such as: the support developed by the wings of an airplane, the drag force that acts on automobiles, buildings, power transmission lines and among other phenomena. Routine. This work aims to study the distribution of the pressure coefficient (Cp) in the flow over an acrylic cylinder in a wind tunnel. In order to achieve the goal, an area reducing accessory with a test area of 225 cm² was designed and built, a 26.6 mm diameter acrylic cylinder was designed and made. 3 mm in diameter, it acted as a Pitot tube and served as a channel for the fluid to flow through the pressure sensor. It is noteworthy that the acrylic cylinder was manufactured in the Laboratory of Fluid Mechanics (LMF), the area reducing accessory provided a speed increase from 6.03 m/s to 24.08 m/s. Electronic equipment was used, such as: the MPX5050DP pressure sensor that measured the pressure differential; an ADC ADS 1115 card that converted the analog signal to digital, a B10K potentiometer for cylinder angle measurement, and an Esp 32 WiFi LoRa microcontroller that transmitted the circuit-mounted signal to the computer via the USB cable. For the tests the acrylic cylinder was coupled to the area reducer accessory, then the cylinder and reducer assembly was coupled to the wind tunnel, the pressure sensor was calibrated, the potentiometer was adjusted and the wind tunnel was turned on, The cylinder was manually rotated around its axis, the experimental data were collected through the pressure sensor connected to the Pitot tube and these data were analyzed. Analyzing the data, the experiment approached the literature, obtaining maximum and minimum Cp values close to those of the theory, as well as a similar Cp behavior to the literature.