SEL Thermal Card Guide
|Sponsor:||Schweitzer Engineering Laboratories|
|Duration:||Fall 2017 - Spring 2018|
|Team Name||Cooler Than Before|
The goal of this project is to develop a card guide design that can be applied in SEL equipment that has a net thermal resistance less than 1 ⁰C/Watt between an aluminum tray (.05"-.1" thick) and the chassis (.05"-.1" thick). This involves creating an instrumented test stand for measuring heat transfer across the card guide. Results should be reconciled against an analytical model to assure accuracy. The recommended solution should meet SEL standards for vibration.
Mathematical heat transfer model Experimental test set-up that can accommodate different guide configurations Experiment design and test results that demonstrate which guide configurations are most effective Comprehensive project documentation for easy future reference by client
|Part Cost||Card guide needs to cost less than $5.00/part.|
|Dimensions||The card guide is to be 5in* long, 0.38in wide, and 0.50in tall. *Possible to design product such that the length is variable.|
|Thermal||Net thermal resistance of the guide must be ≤1°C/W between the tray it is supporting and the chassis it is fixed to.|
|Mechanical||Must pass industry standard vibration testing.|
To determine a suitable card guide our group had to model potential heat transfer rates using solidworks thermal modeling system. Alongside this we are ussing EES to create a math model of the conduction heat transfer of our test setup.
For our test setup we have created a scale version of the thermal card guide.
After completing a test with the new material and thermocouples, convective heat loss does seem to cause issues when conducting the test in open air. Using the equation: R_t=(T_1-T_2)/q_x =L/kA We were able to calculate resistance values in the model. With temperature values obtained from the test T1 = 54⁰C and T2 = 36⁰C (see image below). The power input to the system was qx = 7.068 W. Measuring the dimensions of the tray and distance between the thermocouples we found A = 82.656x10-6 m2 and L = 0.135 m. Using these values the expected resistance value was Rexpected = 12.098 ⁰C/W. We have concluded that the convection heat loss is not allowing us to acquire correct measurements in open air. Looking at the resistors for our power input, they have fins around the entire housing allowing for greater convective loss resulting in power that isn’t being sent into the tray.
| Marc Dobson
| Collin Mabe
| Nick Tobe
| Michael Wendell
|I am a Senior in Mechanical engineering at the University of Idaho. I plan to graduate and continue my education by getting a masters degree in Business. My interests include working on my motorcycle and playing soccer.||Mechanical Engineering|