Learning Objectives
After completing this module, you should be able to:
1. Understand the relationship between force and stress, including how stress is calculated and the difference between normal stress and tangential stress.
2. Calculate frontal and cross-sectional area.
3. Define density and identify its units.
4. Apply basic momentum principles and identify the correct units for momentum.
5. Understand the concept of relative velocity, particularly in the context of fixed control volumes and moving control volumes.
6. Distinguish between uniform and non-uniform flow profiles and understand the no-slip condition.
Videos
Title: M7V1 – Visualizing Flow Streamlines
Summary: The video lecture shows how streamlines—curves tangent to a flow’s velocity vectors—reveal fluid behavior. Using a steady 2‑D field, the instructor draws streamlines, then compares flow around three objects: a streamlined shape (little disturbance), a bluff body (stagnation point, high drag, wake), and a smooth sphere (intermediate). Close streamlines mark fast flow; wide gaps mark slow “dead zones.” These ideas explain phenomena like fish resting behind rocks.
Learning Objectives: After watching this video, you should be able to define a streamline, interpret a streamline plot from steady vs. unsteady flows, locate stagnation points, high-speed zones and wakes using streamline spacing, and apply it to drag reduction and natural flow habitats.
Transcript: Read the transcript
Slides With Annotations: See the slides
Title: M7V2 – Relative Velocity
Summary: This video lecture revisits your understanding of relative velocity within the Reynolds Transport Theorem (RTT). The RTT tracks any extensive property (mass, energy, momentum) across a control volume (CV). Its velocity term carries a subscript vᵣ to remind us that the speed must be measured relative to the chosen control volume (CV), this is important because analyses of fluxes are only correct when the velocity is relative to the moving or stationary CV that encloses the flow.
Learning Objectives: After watching this video, you should be able to understand why RTT uses fluid speed relative to the control volume, manipulate the relative velocity equation, differentiate between fixed and moving control volumes, and calculate relative velocities.
Transcript: Read the transcript
Slides With Annotations: See the slides
Title: M7V3 – Momentum
Summary: This video provides a review of linear momentum to prepare students for analyzing momentum fluxes in control volumes. It defines momentum as the product of mass and velocity, discusses its units in both SI and US customary systems, and explains how different mass-velocity combinations can yield the same momentum. The video revisits Newton’s second law, emphasizing its form as the time rate of change of momentum and highlighting the condition for momentum conservation: zero net external force.
Learning Objectives: After watching this video, students will be able to explain the concept of linear momentum, relate it to Newton’s second law, and apply the principle of momentum conservation to analyze closed systems with no external forces.
Transcript: Read the transcript