Date of Award


Degree Name

Master of Science in Engineering


Mechanical and Aerospace Engineering


Mechanical and Aeronautical Engineering

First Advisor

Dr. Daniel J. Dorney

Second Advisor

Dr. Parviz Merati

Third Advisor

Dr. Iskender Sahin

Access Setting

Masters Thesis-Open Access


The wings on aircraft can experience unsteady loads due to atmospheric disturbances; e.g., wind, the wakes of other aircraft, structural vibrations, or some combination of these sources. In some cases flow unsteadiness can be beneficial by augmenting the lift and reducing the drag; under different circumstances temporal variations in the flow can induce stall or cause structural failure.

In this study, the response of isolated (and tandem) NACA 0012 airfoil(s) to time-periodic unsteadiness have been investigated. The sources of unsteadiness include a time-varying free stream flow angle, a time varying free stream velocity magnitude, and an oscillating airfoil.

The predicted results indicate that the three types of unsteadiness investigated can generate additional airfoil lift and produce thrust (instead of drag) during a significant portion of an unsteady oscillation cycle.