Open AccessThe effect of PPI on thermal parameters in compact heat exchangers with aluminum foam
Author(s) -
Bernardo Buonomo,
Anna di Pasqua,
Davide Ercole,
Oronzio Manca
Publication year - 2019
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1224/1/012045
Subject(s) - metal foam , materials science , heat exchanger , heat transfer , porosity , mechanics , composite material , porous medium , thermodynamics , reynolds number , darcy number , aluminium , micro heat exchanger , tube (container) , thermal , plate heat exchanger , natural convection , turbulence , rayleigh number , physics
A numerical analysis on a compact heat exchanger in aluminum foam is accomplished. The governing equations in two-dimensional steady state regime are written in local thermal non-equilibrium (LTNE). The physical domain under investigation is made up of a plate in aluminum foam with inside a single array of five circular tubes. The presence of the open-celled metal foam is modelled as a porous media by means of the Darcy-Brinkman-Forchheimer law. The metal foam is characterized by a porosity of 0.93 and different pores per inch (PPI), equal to 5, 10, 20 and 40 are analized. The LTNE assumption is considered to simulate the heat transfer between the fluid phase and the solid matrix of the foam. The compact heat exchanger at different air flow rates is studied with an assigned surface tube temperature. The results are shown in terms of heat and mechanical power ratio. Global parameters such as effectiveness and NTU, typical in compact heat exchangers, are showed. Furthermore, local air temperature and velocity profiles in the smaller cross section, between two consecutive tubes, as a function of Reynolds number are presented.