The propulsion efficiency lab was designed to familiarize students with propulsion system efficiency and wind tunnel testing equipment. This lab also intended to give the AEV real world significance and link the testing performed in the wind tunnel to the AEV project. The main focus in the AEV project thus far and this lab was efficiency. In terms of this project, efficiency relates to a systems ability to maximize energy. Efficiency can be measured quantitatively by observing the ratio between useful power output and total power output. To find the propulsion efficiency of an AEV, a ratio of the motor efficiency and propeller efficiency is observed. The main factors influencing propulsion efficiency were the type of motor and the type of propellers. Because testing various motors can be costly, testing a variety of propeller configurations can improve the efficiency of an AEV. This is often done in a wind tunnel. The wind tunnel testing helped students determine the most efficient propeller, propeller configuration, and the operating conditions that are the most energy efficient.
Based on the results displayed in the charts below, the team determined that the 3030 propeller in the puller configuration would be the most efficient option. The 3030 propeller had a higher efficiency than the 2510 propeller. Another drawback of the 2510 propeller is the inability to use a lower power setting. In order to use a lower power setting, the 3030 propeller would have to be used. Though the puller system is more efficient than the pusher system, the team will use both. However, while designing the AEV, the team will want to use the most efficient configuration when the AEV returns after picking up the caboose. The extra efficiency would counteract the extra weight the caboose added to the AEV. When returning with the AEV, a high power setting will be used. This will lower the advance ratio. A lower advance ratio means the AEV would be travelling farther because the RPM value would increase. This increase in efficiency would help the AEV meet the goals set in place by the lab manual.
The objective of this lab was to determine which propeller size and configuration would be power the AEV most efficiently. The lab gave the engineers a process to test the efficiency for propellers and other parts of the AEV. It also familiarized the group with wind tunnel procedure and calculations. Lastly, the lab gave engineers formulas to calculate power and efficiency for any electric component. Calculations of power and efficiency show that the most efficient propeller to be the 3.5 inch propeller in the pusher configuration.
Team Meeting Notes:
Date: 18–February–2016
Time: 10:30am-12:30pm
Members Present: Kailee Gulbin (KG), Ben Reed (BR), Paul Conway (PC), Grant Miller (GM)
Topics Discussed: Lab 5 Post-Lab
Objectives:
Today’s main focus was meeting as a team to discuss how to prepare an Executive Summary for Lab 5 and update the u.osu.edu website.
To do:
-u.osu.edu (KG)
-Executive Summary (PC, KG, GM, BR)
Reflections:
-The u.osu page was not finished completely, need to finish the final paragraph.
-The executive summary was not proof read, and the analysis section was not finished.