Subject: Project 3, Terminal Velocity
In this project you are asked to prepare a spreadsheet to calculate terminal velocity for objects of various sizes and materials falling through different fluids. The purpose is to help a high school science teacher explain the concept of terminal velocity to a class of 11th grade students. In addition to the concept, you should provide an example of how this concept can be used for industrial applications. Investigate the application using your model to generate appropriate data. Plots and tables should be included in the memo with your discussion. Printed and electronic file copies are due at the time of the final exam. Remember to write for your audience, follow the guidelines for memos, document your work and pay attention to your visual display of data (tables and plots â follow the guidelines).
When an object falls in a fluid its downward motion is opposed by a buoyancy force and a drag force. The buoyancy force is equal to the weight of fluid displaced by the object. The drag force is proportional to the square of the velocity and depends on properties of the fluid and the object. If the distance travelled is long enough, the object will reach a constant velocity, called the terminal velocity. The equations below show this concept applied to a spherical object:
The drag coefficient ( CD ) is a function of the Reynold’s number, with the latter calculated from the expression Re = (fluid density * velocity * diameter)/ (fluid viscosity). Note that the fluid properties are used here along with the velocity and diameter of the particle. Equations and symbol definitions are provided in a spreadsheet posted with this assignment sheet.
The Spreadsheet Model
Design your spreadsheet to solve for the terminal velocity of a sphere using iteration. Solver may be used to implement the iteration, however, you will need to set up the sequence of calculations.