Dr Robert Woolley2026-06-082026-06-08https://dspace.academy.edu.ly/handle/123456789/2221Thermal performance measurements were conducted using an unsteady-state technique (single-blow technique). To evaluate the thermal performance a single blow model was solved numerically to predict the number of the transfer unit of each matrix. Furthermore, two data reduction techniques (direct and maximum slope matching techniques) were adopted to predict the thermal characteristics of the tested samples. The hydrothermal performance of regenerator matrices was characterized in terms of volumetric Nusselt number and Reynolds numbers based on the Darcy permeability.The primary object of this work is to investigate if it is possible to improve the flow and thermal performance of porous media by combining two different types of media. Aluminuin open cellular materials were combined with woven wire mesh screens and experiments were performed to investigate the pressure drop and thermal performance of the samples. The samples were tested as regenerators where the fluid is passed through the porous media to packed beds. Thirty-six heterogeneous regenerators were constructed from square woven mesh screens, having mesh sizes 20, 30, 40 pores per inch and combined with six different types of metal foams. The aluminium foam samples were further subdivided on the pore shape: spherical and irregular. Each category consisted of three foam samples having different pore sizes (small pore (1-1.18 mm), medium (1.4-1.7 mm) and large (2-2.36 mm)). Two test rigs were developed to measure the hydraulic and thermal performance of the semi-homogeneous and heterogeneous matrix materials using dry air with velocity from 0.01 m/s to 6 m/s (Darcy permeability based Reynolds number ranged from 0.002 to 80). For the hydraulic performance, the pressure drop profiles against the air velocity were measured under steady-state conditions. Several flow regimes with the transition zone between them were identifiedFORCED CONVECTIVE HEAT TRANSFER