Ph.D. Thesis Defense

Waheed Bello

(Faculty advisor: Prof. Kai James)

"Application Of Topology Optimization Methods To The Optimal Design Of High-Performance Heat Exchangers"

Friday, September 18

12:00 p.m. 

Montgomery Knight Building, 325

Abstract: 

Heat exchangers are essential in aerospace applications, where effective thermal management is required for the reliability and performance of aircraft and spacecraft systems. These devices are required to be compact and lightweight while also operating under extreme environmental conditions. Topology optimization, which has successfully been applied to the design of efficient lightweight structures, offers the potential to create heat exchangers with unconventional configurations that enhance overall system performance.
This research explores the application of topology optimization to the design of high-performance heat exchangers. The proposed methodology is divided into three key stages. The first stage focuses on the development of a topology optimization framework based on a Darcy flow formulation for pipe configuration design of bi-fluid heat exchangers, exploring how variations in inlet location and pipe sizes could enhance thermal efficiency. The second stage integrates data-driven surrogates such as convolutional neural networks (CNN) with the topology optimization framework, improving the fidelity of the predicted flow fields. The final stage advances to a full-form design of a dual-flow 3D heat exchanger with arbitrary inlet conditions. This stage examines the additional efficiency gains through a combination of organic flow paths and flexible inlet configuration.
The methodology utilizes both finite element and finite volume methods for the multiphysics analysis of the system, applying discrete and continuous adjoint formulations for sensitivity analysis respectively. The design objective is to optimize thermal efficiency by maximizing the average temperature and heat transfer rate under performance constraints, such as material strain energy distribution and power requirements. The resulting framework provides an efficient approach for the design of next-generation heat exchangers and establishes a foundation for the application of topology optimization to coupled fluid-thermal-structural problems.

Committee:

Dr. Kai James (advisor), School of Aerospace Engineering
Prof. Graeme Kennedy, School of Aerospace Engineering
Prof. Claudio Di Leo, School of Aerospace Engineering
Dr. Raphael Gautier, School of Aerospace Engineering
Dr. Prabhakar Marepalli, Google