Comparative Thermo-Structural Analysis of Different Honeycomb Pads for Performance Enhancement of Direct Air-Cooling Systems

Abstract

Honeycomb cooling pads are widely used in direct air-cooling systems due to their high wetted surface area and effective heat and mass transfer characteristics. However, the influence of honeycomb geometry on thermal performance has not been sufficiently quantified. In this study, a comparative thermo-structural finite element analysis of three honeycomb pad geometries (square, rectangular, and circular) is performed under identical steady-state operating conditions. Temperature distribution, thermal gradients, heat flux, and thermally induced stresses are evaluated using consistent material properties and boundary conditions. The results show that the rectangular honeycomb pad provides approximately 12–18% higher effective heat flux and more uniform temperature distribution compared to square and circular configurations. Structural stresses in all geometries remain within safe limits. The findings demonstrate that honeycomb geometry plays a critical role in cooling effectiveness and provide design guidance for selecting optimal pads in direct air-cooling systems.

Introduction

The text presents a comparative study of honeycomb pad geometries used in direct air-cooling systems integrated with vapor compression refrigeration. Honeycomb pads, with their complex cellular structures, are critical for effective heat and mass transfer between air and water, reducing air temperature via evaporative cooling before it reaches downstream components like condensers or compressors. Their performance depends on thermal efficiency, structural integrity, durability, airflow, and moisture exposure, making design optimization essential for compact, energy-efficient cooling systems.

This study focuses on three honeycomb pad geometries—square, rectangular, and circular—made from treated cellulose. Using finite element analysis (ANSYS) under steady-state thermal and structural conditions, the research evaluates temperature distribution, heat flux, stress, deformation, and factor of safety for each geometry. Boundary conditions included an inlet air temperature of 52 °C, ambient 27 °C, and uniform convective heat transfer at 25 W/m²·K. The analysis simulates airflow and thermal loads typical of direct air-cooling applications.

Key findings include:

• Geometry significantly affects thermal performance: Cell shape and orientation influence heat transfer pathways, resulting in differences in total and directional heat flux.

• Structural behavior varies by geometry: Von Mises stress, shear stress, and deformation are influenced by the cell layout; non-load-bearing regions help maintain overall stability and airflow uniformity.

• Optimized designs reduce material usage while preserving adequate structural integrity and consistent heat transfer.

• One geometry showed superior thermal performance, with lower temperature gradients and more uniform heat flux distribution, while meeting safety and deformation limits.

The study highlights that selecting the optimal honeycomb pad geometry is crucial for maximizing cooling efficiency, maintaining mechanical stability, and minimizing material and manufacturing costs in direct air-cooling systems.

In short: geometry drives performance—thermal efficiency and structural integrity can be simultaneously optimized through careful design and finite element analysis of honeycomb pads.

Conclusion

A comparative thermo-structural analysis of three honeycomb pad geometries was carried out using finite element simulations. Based on the results, the following conclusions can be drawn: 1) Honeycomb geometry strongly influences temperature uniformity and heat flux distribution. 2) Rectangular honeycomb pads exhibit 12–18% higher effective heat flux compared to square and circular geometries. 3) Thermal stresses in all pad geometries remain within safe limits, ensuring structural reliability. 4) Rectangular pads provide the best balance between thermal performance and mechanical stability. Therefore, rectangular honeycomb pads are recommended for direct air-cooling systems to enhance cooling effectiveness and long-term durability. The outcomes of this study provide a practical basis for selecting honeycomb pad geometry in energy-efficient air-cooling system design.

References

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Copyright

Copyright © 2026 Himanshu Patel, D S Rawat. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.