About this tool:

Flow and thermal property charts can be used by design engineers to select a suitable topology of structures for their requirements. It is a complete correlation between flow and thermal characteristics of different topologies of lattice structures.

Background

The emergence of Metal Additive Manufacturing has provided gas turbine design engineers with valuable design options, including the utilization of cellular solids. Nevertheless, there remains a dearth of research concerning the early selection of these structures and their interactions with fluid flows. Lattice structures, known for their adaptability in achieving specific properties such as high porosity, strength, energy absorption, and lightweight characteristics, have been thoroughly explored in terms of their mechanical performance. However, there is a significant paucity of research investigating their flow and heat transfer performance, particularly for strut-based lattice structures.

Nomenclature:

  • VS - Volume of the unit cell of topology
  • Q - Heat transfer rate
  • h - Convective heat transfer coefficient
  • ∆T - Temperature difference
  • Re/Ref - Reynolds number of fluid domain
  • f - Darcy friction factor
  • f0 - Friction factor for hydraulically smooth channel
  • d - Diameter of the struts in the topology
  • t - Thickness of the surface of TPMS topologies
  • Red/t - Reynolds number based on strut diameter or thickness
  • AP - Apparent Porosity
  • AL - Available surface area for heat exchange
  • Properties investigated:

    Two very important thermal properties which are compared for different topologies are:

    1. Heat transfer rate (Q) per unit temperature difference (∆T) in W/K across different structures

    2. Convective heat transfer coefficient (h)

    The flow properties, such as the friction factor (f), play a crucial role in assessing the pressure losses across different lattice structures. These properties typically exhibit variations based on the apparent porosities of the structures. Apparent porosity refers to the ratio of the 2D projected area of the topology to the total 3D surface area of the lattice, which is available for heat transfer. By considering the apparent porosity, one can better understand and analyze the impact of these structures on flow characteristics and pressure losses.

    The correlation between the flow and thermal behavior of compressed air across these structures is finally demonstrated through the relationship between the convective heat transfer coefficient and the friction factor. This correlation provides a comprehensive understanding of how the flow characteristics influence the thermal performance of the compressed air in these structures.

    To access more information about the obtained results and related research, please refer to the links provided below. These links will direct you to additional resources, such as research papers, articles, or reports, where you can delve deeper into the findings and explore the broader context of the study. These references can provide you with a comprehensive understanding of the subject matter and offer further avenues for exploration and learning.

    Publications, Conferences and Thesis:

    1. Sarabhai, S., Letov, N., Kibsey, M., Sanchez, F., & Zhao, Y. F. (2023). Understanding the flow and thermal characteristics of non-stochastic strut-based and surface-based lattice structures. Materials & Design, 227, 111787. Reference

    2. Accepted for ASME Turbo Expo 2023 (To be held from 26th June 2023).

    3. Sarabhai, S. (2022). A Holistic Study on Flow and Thermal Characteristics of Non-Stochastic Strut-Based and Surface-Based Lattice Structures for Gas Turbine Engines, McGill University. Reference

    Soft tools used:

    nTopology, Siemens NX, ANSYS Fluent and StarCCM+.

    © ADML 2023