156B Week 4 Progress Report

Overview of Status of Analysis, Design, Fabrication, Tests, etc.

• Devised novel cooling strategy, using cold airflow across bottom surface of test substrate to cool without requiring added mass to test module.

• 3D printed first hardware iteration, made refinements based upon observations and new standards for performance.

• Obtained much of the required hardware:

  • Steel stock and thermocouples for emulation of test environment.

  • Control supplies (Arduino Nano, Feather, IR temperature sensors, etc.)

  • Ordered other necessary supplies and awaiting sponsor shipment of test silicon coupons.

• Revamped project timetable (due to replacement of the Peltier cooling solution with the cold airflow alternative).

Accomplishments from Previous Week

• • Produced first hardware iteration based upon CAD model (3D printed on Makerbots)

  • Clarified new cooling solution, performed sanity check flow simulation using Solidworks and verified viability.

  • First working CAD design completed and ready for refinement.

  • Hardware assembly is beginning now that many components have arrived.

Assignments for Coming Week

    Jayant Mathur

• 1. Design control loops and communication (telemetry) schemes.

  2. Assist with implementation of hardware and coordination between data collection and test structure.

  3. Assist with CAD and design of cold air injection nozzle.

  Nate Goldberg

• 1. Perform necessary heat transfer calculations for cold airflow across bottom surface of coupon stack.

  2. Design basic cold air injection nozzle according to required dimensions from calculations.

  3. Perform necessary simulations of heat transfer and cold airflow.

  Kristen Matsuno

• 1. Supply fluid calculations (shear forces, thermal boundary layer effects, etc.)

  2. Continue refining assembly CAD model.

  3. Investigate non-contact thermal measurements (IR temperature sensing).

  4. Assist with design of cold air injection nozzle.

   Nathaniel Liu

• 1. Continue design on test method to emulate the heated airflow using a solid thermal mass.

     1. Machine stainless steel stock square bar.

     2. Perform necessary calculations and design control loop for testing and data collection.

1. Assist with CAD of coupon stand assembly and cold air injection method.

Sponsor Feedback and Corresponding Action Items

    Sponsor approves of new cooling solution (cold air sheet to underside of coupon). Suggested caution to minimize injection method impact on airflow characteristics.

        Accordingly, the nozzle will be designed to supply an airflow that does not interact strongly with the heated airflow (shielded from mixing until after the coupon length).

    Sponsor requested the holes drilled into the test chamber to be minimized, preferably such that the Chill Puck utilizes the holes that already exist and that new holes do not exceed 0.5" diameter.

        To this end, Chill Puck designed to be inserted in the same way as the previous "Hot Puck" test device, and holes will be planned carefully to minimize modification to test chamber.

Instructor Feedback and Corresponding Action Items

    Professor Tustaniwskyj much more fond of new idea to use cooling air flow "sheet." Suggested inclusion of a tuning resistive heater to accommodate potential lag in the system.

    This additional heater would require more hardware to be added to the Chill Puck, but could provide a well-defined means of "trimming" or "tuning" the thermal control system.

Comments from Other Students

    Student feedback for Design Proposal Presentation received, allowing for refinements in further presentations.

Risks and Areas of Concern

Thermal control might be difficult to achieve due to lag in thermal response to system flow rate changes. To remedy this, suggested Joule heater implementation and/or increase in overall "thermal mass" of stack below coupon.

Containment of dry ice for cool air flow potentially hazardous (pressurized ampoule difficult to characterize), or potentially insufficient (a temporary styrofoam design could leak too much CO2).  

Resources or Information Required but not Available

Further details about preexisting test structure still required (pressure in chamber, means of thermal control, etc.)

Silicon coupons for testing are required, pending sponsor shipment.

Schedule

    Monday 4/24 - 10:00 am Team meeting

                            3:00 pm  Meeting with Professor T.

                            4:00 pm  Secondary team meeting for assembling hardware.

    Wednesday 4/26 - 2:00 pm  Phone call with sponsor contact (Jeremy)

                                  5:00 pm  Team meeting (revamp 3D printed parts)

    Friday 4/28 - Team meeting to decide upon details of second design iteration.

Budget

• • $35 Spent on Risk Reduction (Winter 2017)

  • $11.37 Adafruit Trinket

  • $19.31 Adafruit Thermocouple Amplifier

  • $8.12 Battery "backpack" add-on

  • $16.99 Ofeely 3.7V 3000mAh LiPo Battery

  • $11.99 Halnziye High Performance Thermal Grease

  • $11.98 Arctic Silver Cooling Adhesive

  • $8.44 ThermalCoolFlux Thermal Paste

  • $12.99 Ultronix ThermoSensor

  • $13.27 Adafruit Infrared Thermo-sensor.

  • ~$1000.00 Remaining Budget for Equipment and Parts (approximate estimate, pending quote for Adafruit supplies)

Progress on Report and Webpage    

    Drafted "Impact Upon Society" section of final report.

    Continuous report refinements and pending website additions.