1. Mechanical Subsystems LabVIEW Code for Feedback Loop
The Meniscus Project (P16371)
Team Members:
Robert Walkowiak – Mechanical Engineer
Alyssa Recinella – Mechanical Engineer
Charles Krouse – Mechanical Engineer
Joseph Baldwin – Mechanical Engineer
Advisors:
Dr. Satish Kandlikar
Harold Paschal
Pruthvik Raghupathi
Project Overview
Mechanical Subsystems
A boiling system can be an incredibly useful tool for removing vast amounts of heat from a surface. However, due to the complexity and chaos of a boiling environment, the fundamental physics of a nucleating bubble are not well understood. For this reason, the RIT Thermal Analysis, Microfluidics, and Fuel Cell Laboratory (TAµFL) has proposed a system that is capable of studying bubble nucleation at a fundamental level. The goal of this senior design project is to design TAµFL's proposed system in order to meet the requirements for observing and studying bubble nucleation. This will be accomplished by designing, and then constructing, an apparatus that creates a stable liquid meniscus, is capable of controlling the meniscus's volume, and is able to oscillate the meniscus at a desired frequency. The applications of understanding bubble nucleation pertain to any system that requires heat dissipation, ranging from jet engines to computer chips.
Final Design Overview
An oscillating meniscus was created using various integrated components. After various design considerations, the following parameters were chosen: a cone speaker to induce oscillations, a syringe pump for liquid injection, a stage to vary the distance between the needle and copper surface, a capacitance sensor to assist in feedback controls and a high speed camera for in-depth visualization.
Customer Requirements
Cone Speaker: The method selected for generating the oscillations, a cone speaker, is an inexpensive and readily available option with a relatively high power output that can produce consistent oscillations.
Liquid injection: The liquid injection system of our setup consists of two syringes and two syringe pumps in order to supply the working fluid to the speaker and needle. Swagelok connections are used to seal the system and allow for easy disconnections and reconnections.
Capacitance Sensor: Utilizes a Schering bridge circuit in order to determine the relative volume of the meniscus. Output from the capacitance sensor is input into LabVIEW in order to supply an adequate flow rate and maintain a stable meniscus. This ensures that the meniscus does not evaporate away or flood the copper chip.
Height Adjustment: A motorized stage is used to adjust the height between the needle and copper chip. The motor is controlled via an external program on the computer and allows for very fine height adjustments. Adjusting the height enables us to use various working fluids and change the shape of the meniscus.
LabVIEW Code for Feedback Loop
System Design
Results
Increasing contact angle
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Acknowledgements
We would like to thank the following people for their guidance and assistance throughout this project:
MSD Office and Dr. Elizabeth DeBartolo
The Machine Shop – Rob Kraynik, Jan Manetti, and Craig Piccarreto
Professor Wellin and Professor Lam
Financial support from TAMFL
Accomplishments
Decreasing contact angle
Submitted paper to ASME ICNMM 2016 conference
Presenting at conference in July 2016 in Washington DC
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