Title: Parametric Study of High Temperature Springs for Solid Oxide Fuel Cells
Name of NGM Educator: Alfred Gates, Ph.D., Engineering Department Head |
Name of Host Company: FuelCell Energy |
Grade Level: College Juniors and Seniors
|
Student Work Types:
|
Task Abstract: Predict the reduction in strength, % relaxation, of springs over time at high temperatures subject to different initial loads using experimental material testing data. The results of the % relaxation for different materials and the material cost will be used to determine the cheapest and most effective spring combinations to provide a sustained force over a period of time at the operating temperature of a Solid Oxide Fuel Cell.
|
Task Objectives: Students will learn how to use compression spring experiential data, material fatigue rupture data and curve fitting techniques to estimate the % reduction in spring material strength over time based on temperature and initial corrected shear stress for springs with a spring index close to 6. Using this data along with equations students will be able to design springs for high temperature applications. |
Esssential Understandings/Questions:
|
Task Description: Students will;
|
Resources Required:
|
Prior Learning Required:
|
Context within which work is produced:
classroom |
Individual or Group Work: Individual |
Special Needs: n/a |
Educator Comments: Designing springs for applications with Solid Oxide Fuel Cells provided a learning experience dealing with limited information and making engineering judgments with experimental data. Students will gain from my experience an unpublished method of designing springs for high temperature applications. They will understand that material loses a percentage of strength over time, % relaxation or % reduction in strength, when subject to high temperatures. The students will also understand that some strength reduction is acceptable but that there will be a limit on the maximum allowed reduction in strength. Students will learn how to set up a spread sheet using compression spring data provided in a Machine Design text book providing a particular desired output. Finally the students will be able to apply this to different materials to determine the lowest cost springs for a particular application. This procedure can be applied to designing other structural load bearing members. The requirements of applying a similar procedure are having the following information; engineering equations that represent a maximum stress state, experimental data from structural test and material tensile test data.
|