Kraft IV, Edward August (2018-08). Thermal Hydraulic Performance of Aluminum Metal Foam Heat Exchangers with Varying Cellular Lattice Structures. Master's Thesis. Thesis uri icon

abstract

  • Due to their large surface area to volume ration, low density, and high strength structure, aluminum metal foams offer a promising application for heat exchangers. One significant design challenge of aluminum foam heat exchangers is optimizing the trade-off between heat transfer performance and pressure drop (i.e., pumping power). Previous experimental investigations successfully quantified the thermal hydraulic behavior of such heat exchangers based on foam porosity, but they provide limited insight on the effects of varying cellular lattice structures within their samples. As a result, a Computational Fluid Dynamic (CFD) analysis using Star CCM+ is carried out for the thermal hydraulic behavior of aluminum foam heat exchangers based on varying cellular lattice structures. Two secondary studies were also undertaken, including the comparison of the thermal-hydraulic performance using different meshing styles (structured vs unstructured) and different CFD software (Star CCM+ vs ANSYS Fluent). Pressure drop and heat transfer performance were analyzed based on three criteria: unit cell geometry, relative density, and orientation. Performance rankings were developed according to pressure drop and heat transfer. Pressure drop and Nusselt number correlations were formed for heat sink designs. It is recommended to use models with unstructured mesh for pressure drop data and models with structured mesh for thermal data. Finally, both CFD codes resulted in nearly identical pressure drop and thermal data.
  • Due to their large surface area to volume ration, low density, and high strength structure, aluminum metal foams offer a promising application for heat exchangers. One significant design challenge of aluminum foam heat exchangers is optimizing the trade-off between heat transfer performance and pressure drop (i.e., pumping power). Previous experimental investigations successfully quantified the thermal hydraulic behavior of such heat exchangers based on foam porosity, but they provide limited insight on the effects of varying cellular lattice structures within their samples. As a result, a Computational Fluid Dynamic (CFD) analysis using Star CCM+ is carried out for the thermal hydraulic behavior of aluminum foam heat exchangers based on varying cellular lattice structures. Two secondary studies were also undertaken, including the comparison of the thermal-hydraulic performance using different meshing styles (structured vs unstructured) and different CFD software (Star CCM+ vs ANSYS Fluent).
    Pressure drop and heat transfer performance were analyzed based on three criteria: unit cell geometry, relative density, and orientation. Performance rankings were developed according to pressure drop and heat transfer. Pressure drop and Nusselt number correlations were formed for heat sink designs. It is recommended to use models with unstructured mesh for pressure drop data and models with structured mesh for thermal data. Finally, both CFD codes resulted in nearly identical pressure drop and thermal data.

publication date

  • August 2018