More Fun With Infinite Wings
Hello again, it’s weird to think that this spring quarter is now 40% complete but with each passing week comes new and exciting errors in our Matlab calculations. This week we continued to test the infinite wing with a NACA 4412 airfoil. This week we recorded and attempted to process the recorded pressure data across the upper and lower surfaces of the wing. My team decided to examine the wing in the same orientations but at different Reynolds Numbers. Reynolds Numbers are used to compare and estimate the characteristics of flow around similar objects. The number itself is calculated using the geometry of the object, the density of the fluid, the viscosity of the fluid, and the velocity of the fluid.
Our tests were similar to the previous week in testing the properties of the airfoil at post-stall angles of attack. We recorded data from 0-degrees up to 25-degrees. Throughout the testing one of the group members was analyzing the data recorded and comparing it to a fairly accurate computer program called Xfoil. All of the pressure data recorded matched up really well to the Xfoil approximations.
The majority of our problems showed up when analyzing the pressure data to calculate the coefficients of lift and drag of the airfoil. So many problems that in a 3 hour class period this past Thursday we only solved errors that led to more difficult errors. At the end of the day we had made negative progress on our calculations. How bad was our code you ask? If the numbers were to be true we would be some of the best engineers to test the NACA 4412. We had a negative drag, meaning that the force of the air opposing our forward motion was actually pushing us forward at a greater and greater rate. My team is planning on meeting this Sunday to try and complete this code and have some valid graphs for our upcoming lab report. Until next time.