ISSN Online: 2688-7231
ISBN Online: 978-1-56700-524-0
Proceedings of the 26thNational and 4th International ISHMT-ASTFE Heat and Mass Transfer Conference December 17-20, 2021, IIT Madras, Chennai-600036, Tamil Nadu, India
Generation of design data for wavy fins used in compact heat exchangers for aerospace applications
Compact heat exchangers are growing in popularity thanks to their compactness and high heat transfer ability. The use of fins has been identified as a very powerful method of improving their heat transfer coefficient without adding too much weight. This is most significant in the aerospace industry, where lightness and compactness of systems is key. As these fins can be machined using lightweight materials like aluminum or titanium, they can be extremely light. However, the type of fin used and its geometry needs to be carefully picked for the application. Commonly, Colburn(j) and Fanning friction(f) factor are used as the metrics to judge the performance of a fin with respect to its heat transfer coefficient and the frictional pressure drop respectively. They are commonly referred to as 'design data' of the fin. This work intends to develop design data for Colburn (j) and Fanning friction (f) factors for different wavy fin geometries with air and R134a as the working fluids. A Computational Fluid Dynamics (CFD)
approach is used to validate some of the existing literatures.
The fin geometry is modelled using a CAD software according to the dimensions provided in the literature and meshed. The appropriate boundary conditions are applied and the case is solved in ANSYS Fluent software and the Colburn and Fanning friction factors were evaluated. Using the learnings from validation, this literature will deal with finding these factors in the case of two-phase flow with R134a as the working fluid for different wavy fin geometries with different Reynolds numbers. Existing literatures were successfully validated with minimal errors for both air and R134a as the working fluids and the trends observed from the validation were in agreement with the existing literatures.