Introduction to Fluid Mechanics

This introductory lesson touches experimental, analytical, and computational approaches in the study of fluids. Experimental fluid mechanics provides insights in relationships and behaviors, many of which that can be explained or approximated through mathematical expressions.  In some simple or controlled cases, analytical solutions can be derived to guide further experimentation (hypothesis testing). Computational fluid dynamics (CFD) extends mathematical theory to more complex situations that require the use of computers for deriving solutions. Experimental approaches are typically used to validate / test results from CFD predictions and vice versa (see the figure below).

The following exercises help to develop a sense of the different approaches and their relative strengths and limitations. 

1. Watch the following videos of wet experiments in discuss your understanding with respect to the following concepts: viscosity, no slip conditions, internal friction between fluid layers. (NOTE: clicking each link will download a .mov file. If you have trouple playing the videos, use the VLC player (Official download of VLC media player) 

            Viscous Fluids

Capillary Tube Viscometer

No-Slip Condition

Laminar Flow

Shear Deformation

2. Watch the following videos of computational simulation and visualizations in a particular area of civil and environmental engineering. Discuss what you learned from the videos. Discuss how a groundwater model can be applied to manage water resources, control pollution, and design monitoring networks.

Groundwater Contamination

3. Apply the following numerical model to simulate groundwater flow and contaminant migration, taking advantage of the powerful MAGNET4WATER modeling platform for computational experiments in water resources / environmental engineering, and answer the following questions: 

a. What do the groundwater flow patterns look like? Discuss in relation to the landscape features. 

b. Will the contamination plume hit any of the drinking water wells? Which wells are likely to be impacted?

c. Approximately how long does it take for the contamination to reach the wells? 

Additional modeling details / instructions:

• Go to MAGNET MODEL NETWORK, enter "Fluids Problem" in the search bar, and search. Zoom to the marker that appears in northern Michigan, U.S.A., and click on it.
• A small window will appear. Click on 'Load Model to IGW MAGNET". This will load the model directly into the MAGNET4Water modeling environment.
• The model is "all ready to go". Click on the "Simulation Tools" button along the left-hand side, and then click the red 'SIMULATE' button. Enter your username and password (or create a free account). Then follow the on screen prompts to proceed with simulation.
• When the simulation is finished, the results will be dynamically shown in the map display.

4. Discuss in general the ‘pros and cons’ of the traditional build-and-test wet experimental approaches VERSUS computational simulation-based approach in understanding fluid flow phenomena, analyzing flow, and designing fluid systems.