Self-Regulated Thermal Management with Shape-Memory Alloy Torsional Tubes

<p>The need for dynamic thermal management that adapts to varying system needs and requirements is a growing topic of interest in different engineering disciplines, most prominently aerospace and electronics. This demand for improved thermal management systems comes from the general increase of system efficiencies leading to an increase in component energy density. Shape-memory alloy actuators, which respond with a mechanical shape recovery to variations in temperature, can be used as self-regulated thermal management actuators that are able to respond to environmental thermal changes autonomously. In this dissertation, modeling and experimental analysis of a two-way shape-memory effect trained SMA torsional tube for self-regulated thermal management purposes are considered and developed. The behavior of SMAs under steady-state conditions is well understood. However, self-regulated behavior and non-ideal thermal conditions need to be further investigated. SMA behavior is highly non-linear and path-dependent and common applications use active means of temperature and actuation control using closed-loop systems. This research considers an SMA torsional tube responding autonomously to a process fluid running through, which experiences thermal variations. For these purposes, an experimental setup using air as a process fluid and a preliminary system model are completed to investigate the actuator’s self-regulated response and model prediction capabilities. The model is comprised of a heat transfer and SMA portion, with two SMA models considered (Liang-Rogers and a model based on experimental results). Steady-state, unsteady, and mass flow variation cases are carried out and modeled to analyze tube behavior under different conditions. A sensitivity analysis of different model parameters, including changing the process fluid and SMA tube characteristics, is also carried out. It was concluded that TWSME SMA have the potential to become part of thermal management systems. The main advantages include the simplicity of the design and autonomy, though there is a strong need for accurate prediction capabilities and choosing the right geometry and training for the tube tailored to the application is key.</p>

Name thesis:degree_name

Doctor of Philosophy in Aerospace Engineering

Level thesis:degree_level

Dissertation - Open Access

Discipline thesis:degree_discipline

Aerospace Engineering

Year

2025

Author dc:creator

• Sanjuan Espejo, Paula

• thermal management
• shape-memory alloy
• torsional actuator
• self-regulated
• shape-memory alloy tube
• shape-memory effect
• two-way shape-memory effect
• Aerodynamics and Fluid Mechanics
• Structures and Materials

Repository record dc:identifier

https://commons.erau.edu/edt/906

OAI identifier oai:identifier

oai:commons.erau.edu:edt-1947