Fluid Mechanics #9 - Drag and Lift of an Airfoil (Part 2): Momentum Theorem and Drag Expression

In this new video of the "Integral Theorems" series, we continue our case study on calculating the drag and lift forces on an aerodynamic profile. We now move on to the core of the problem: applying the Momentum Theorem to derive the expression of the drag force. We calculate the projection onto Ox of the net momentum flux leaving the reference volume, and we establish the link between this flux, the external forces, and the velocity field in the wake. In this video: Calculation of the net momentum flux ϕx projected onto Ox. Application of the Momentum Theorem to the reference volume ABCDEGHIJKA. Expression of the external forces acting on the volume. Using Bernoulli's Theorem to eliminate the pressure terms. Derivation of the final expression of the drag per unit span fx as a sum of two integrals of the velocity field (the wake deficit and the induced drag). This fundamental result shows that the drag force can be calculated simply by analyzing the velocity perturbations in the wake, without needing to know the pressure distribution on the airfoil itself. Who is this for? This session is intended for undergraduate science students, preparatory class students, or engineering students who want to master the finer points of the linear momentum theorem in fluid mechanics. Useful Links: Previous Session (Session 8):    • Fluid Mechanics #8 - Drag and Lift of an A...   Watch the Full Playlist on "Incompressible Fluid Mechanics" here:    • 5. Incompressible Fluid Mechanics   Watch the Full Playlist on "Perfect Fluid Mechanics" here:    • 1. Mécanique des Fluides Parfaits   Keywords: Fluid Mechanics, Integral Theorems, Momentum Theorem, Drag, Lift, Airfoil, Wake, Flow Rate Deficit, Induced Drag, Control Volume, Bernoulli's Theorem, Aerodynamics, Incompressible Flow, Linear Momentum, Engineering, Physics. Hashtags: #FluidMechanics #Aerodynamics #IntegralTheorems #MomentumTheorem #DragAndLift #Airfoil #InducedDrag