School: MCCURDY HIGH
Area of Science: Electrical Engineering
Interim: INTERIM REPORT FOR LIFTER PROJECT
DEFINITION OF PROBLEM
1. Introduction and background
Thrust from ionized air
What is a lifter-the concept
Physically, a lifter looks similar to triangular box kit. However, the sides are made of aluminum foil and a wire encircles the top, about 30 millimeters from the aluminum foil. The wire is attached to a high voltage power source while the aluminum foil is attached to a ground wire. The power supply provides 25,000 to 30,000 volts of direct current.
A lifter supposedly works by creating an electrostatic "wind". This is caused as the thin positively charged corona wire ionizes the air surrounding it, which is then repelled from the corona wire and pulled towards the negatively charged "skirt" of aluminum foil. The force of this ion wind combined with the impact of the moving ions on the surrounding air creates a downward thrust, causing the lifter to move upward. (This is essentially how some of the "ionic breeze" air purifiers work.)
PLAN FOR SOLVING THE PROBLEM COMPUTATIONALLY
Math modeling of electric field and moving air particles
We are using the StarLogo program to generate a model of our finished lifter. We will show how the power supply creates an electric field. We also will show how the air particles become charged and create a lift.
Currently, we have not prepared this part of our project with any depth. We prefer StarLogo to Java because it appears easier to use and visualize movement. However, we are not familiar with programming math formulas in StarLogo.
PROGRESS MADE TO THIS TIME
2. Hypothesis or question
We plan to evaluate three hypotheses as follows.
Does a lifter actually lift?
Does ionized air actually move?
Is there a more efficient design for lifters?
3. Description of the experiment or project
Proof concept model
Lifters basically consist of three parts, the corona wire (or positive electrode / anode), the air gap (or dielectric), and the aluminum foil skirt (also collector, ground electrode / cathode). After experimenting with various materials, thin dowels were chosen for the frame for the initial proof of concept model. A hot glue gun proved to be the most effective when compared to PVC liquid glue. The finished frame had three horizontal sides, each eighteen inches long, and a five-inch vertical shaft at each corner. Some bare copper wire (which will eventually carry thirty thousand volts of electricity) was run across the vertical members on each corner.
A computer CRT screen has been used as the power supply for the initial model. The results were mixed. On the positive side we have been able to successful tape into the power supply of the CRT tube, as demonstrated by the sparks created from the corona wire to the skirt. However, we have not had the initial model actual take off. Rough calculations showed that we may 20 grams of lift under ideal conditions, but the initial model weighs 19.8 grams.
We therefore will be constructing a new model with the goal of significantly reducing its weight.
Design of more efficient model
There may be a more efficient way of building a lifter. This design would look, in a way, like a rocket. This design would consist of a frame that looks like a narrow rectangle in which the ionized air moves more directly downward between the two sides of the rectangle.
We are relying on an electric field applet from Caltech for designing a more efficient model. The web site is:
Determine if Ionized Air Moves
The following points will be addressed as we continue to develop a working model.
? We plan to set up a tray with in which an electric wire and aluminum foil are used to shape of a field. Threads in the oil will be used to visualize the shape of the resulting field.
? We plan to use of smoke to detect ionized air movement from the corona wire to the aluminum skirt.
? We plan to tether a successful lifter to correct for what otherwise may be a very unstable machine due to random air movements.
We plan to address the following In items 4 through 6 below as we progress with this project.
4. Gather data and supporting information
Prepare a functioning StarLogo program
Evaluate the possible use a Russian math model for design criteria
Measure amount of lift for various models
5. Present conclusions
Lesson learned for engineering
Lessons learned for math modeling
6. Further Exploration
Other possible designs
This site includes two videos of a lifter in use.
It also refers to theories on why a lifter works.
It includes an image of the electric field.
These related site includes a set of equations to
model a lifter's electrical fields-- may or may not
This is a brief critique of what may or may not be
occurring with a lifter.
This is an in-depth experimental critique of how
This site provides a set of articles on how to build
This pdf file reviews electric fields
This site presents animations of electric fields
This site presents animations of electric fields.
Sponsoring Teacher: Robert Dryja