Abstract Safety Sheet References Front Fairing Arc radius 175 Back Plate 03m30 degrees angle Weightkg Material1 92082 27197 Material Cost1 491717 50859 Weightkg ID: 279276
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Conclusion
Abstract, Safety Sheet, References
Front Fairing - Arc radius 175
Back Plate - (0.3m)(30 degrees angle)Weight(kg)(Material1)92.08227.197Material Cost(1) $491.71750.859Weight(kg)(Material 2)74.69639.362Material Cost(2) $214.37723.617Annual Fuel Consumption(Gallons)13101310Annual Fuel Cost($)4860.14860.1Delta Fuel Consumption in %(material 1)-2.923-0.986Delta Fuel Consumption in %(material 2)-3.026-0.914Fuel Savings(material 1)142.07547.909Fuel Savings(material 2)147.04544.431Payback Period(Materials 1 Cost)(Years)3.4611.062Payback Period(Materials 2 Cost)(Years)1.4580.532Practical? Yes/NoYesYes
Cost Analysis Results
The purpose of this project was to design, evaluate, and optimize 3 different drag reduction devices for a school bus. Out of the three hypotheses, two were met; the spoiler did not decrease F
D
.
The frontal fairing and back plates both would be economically viable to produce if the manufacturing, transportation, and other extra costs could be kept low by mass production, but the frontal fairing design would have many flaws in the real world.
The
transparent material would cover the windshield; if the windshield was damaged it would be inconvenient to fix. Also, the fairing would have to be safety tested and get approval, a difficult process. The fairing’s most fatal flaw is when it gets dirty or when the weather is bad. It would be very unsafe if rain fell on the fairing as there are no wipers on the fairing. Although the fairing is very effective at reducing F
D
, it
would not be practical.
The back plates on the other hand present a promising opportunity. The fuel savings would pay off for the material cost
of the steel
version in only half a year. Due to the relative ease of manufacturing, installing, and transporting steel plates, these could be very inexpensive. The design meets all of the criteria mentioned: it does not pose any safety threat or obstruction to the emergency exit, it is cheap, it is effective, and it adds less than a foot to the bus’s length.
There are drawbacks to this analysis. Depending on the type of school bus and the routes it travels, a drag reduction device could never be practical. In urban areas where school busses stop very frequently and rarely drive at high speeds, stopping and re-accelerating consumes
most
of the bus’s fuel.
The U.S. depends on school buses to transport half the nation’s school-age children. Even with a modest 1-2% reduction in fuel consumption, the potential money saved and potential fossil fuels prevented from being burned would be great if most current school buses were outfitted with the back plates device. Already being implemented by trucking companies, having back plates on current school buses would be a small step in the right direction towards slowing down the pollution of our planet
.
Possible Improvements:
To reduce simulation error and achieve more accurate results, a more detailed model of the bus could be created that has more features of a real school bus like the side mirrors and the minor details. The mesh could also be made to have more elements and more refinement could be added to the region around the bus to get a more detailed understanding of the airflow. Autodesk Simulation CFD also has the ability to add moving parts; the wheels could be made to rotate but this comes at the cost of using more computing power. All these improvements would require a faster computer to run the
simulations on
.