Propeller Thrust

1
Propeller Thrust

• Hiram Gonzalez, Alphonse Sims
• Kate Menees, Chris Davis,
• Carolyn Hawk

2
The Objective

• Use Lab view Instrument to measure the thrust
  from different size propellers.
• Find a way to put different size propellers on a
  motor.

3
How lab view will work

• We need to find several different variables
  Thrust load coefficient, power coefficient, size
  of the propeller, speed of the motor.

4
What is in Lab View

• Converting a volt reading from the resistor into
  Newtons.
• The distance from the resistor to the pivot
  point.
• Distance from the motor to the pivot point.

5
How We Get From Volts to Newtons

• The resistor will show a change in voltage as
  the beam tilts. Then we will use the fish scale
  hooked to the vertical beam to find the pounds
  displaced. After plotting those numbers on a
  graph, we can find the slope of the line which is
  the conversion factor we need for our VI.

6
Comparison of Volts and Pounds
7
Apparatus

• The apparatus is called a vertical beam thrust
  balance. It consists of a pump, metal beam, and
  different propellers.
• Some of the problems we have to worry about is
  tare due to gravitational force,

• (cont.) reflection off the side of the tank, and
  human error in the conversions factor.
• The apparatus is supposed to move with the
  different propellers at a constant speed.
  Displacement needs to be measured.

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Picture of the Apparatus
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Problems in the Project

• Reflection of the jet of water from the
  propeller bouncing off the walls and back to the
  propeller.
• Measuring the displacement that will occur when
  the motor and propeller are turned on.
• Take into consideration the pitch of the
  propeller.
• Shafts had to be made so that the propellers
  could be interchangeable.

10
New Problems

• Have had trouble finding AC/DC adapters that
  work. There is only one in the lab that is
  functioning properly
• Set back when the apparatus got knocked over we
  had to replace the motor because the shaft was
  bent. We also had to reglue the motor on the
  vertical beam.
• The shaft was wanting to move in circles towards
  the end, so we had to support and stabilize it
  with a sort of bearing.

11
Thrust

• Thrust is simply force.
• This picture is a representation of measuring
  thrust from a propeller.
• Instead of using these equations, well use the
  lbs from the fish scale compared to the volts on
  the resistor.

12
Propellers

• Most propellers in the marine industry are made
  out of aluminum, stainless steel, etc.
• There are all sorts of propellers in use today
  and each one has its own design, the most common
  is the elephant ear blade.

13
Budget

• Metal for Shafts6.24
• Propellers.Donated
• Bilge Pump..Donated
• Metal for Apparatus.Donated
• Epoxy...4.00
• 
  Total10.24

14
Other Materials Used

• Resistor
• Wave Modulator
• Other FieldPoint Components
• Computer
• Wave Tank

15
Timeline
16
Hypothesis vs. Results

• The group predicted the large brass propeller
  would perform the best. After we tested each
  propeller we found that the plastic propeller
  performed the best out of the three.

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Conclusion

• Although it was the medium-sized plastic
  propeller that worked best, and not the large
  brass one as we had hypothesized, we were able to
  calculate some thrust. If the lab was going to
  be repeated, things that could be improved
  include accounting for the effect that gravity
  had on the displacement, working more
  efficiently, (although you cant predict
  accidents like the apparatus breaking), and
  having propellers that have fewer variables.