In this study, a closed-form analytical solution is presented for fully developed forced convection in a cylindrical tube partially filled with open-cell metal foam. The flow field is modeled using the Brinkman–Darcy approach, while heat transfer between the solid and fluid phases is analyzed based on the local thermal non-equilibrium (LTNE) model. Compared with the local thermal equilibrium (LTE) assumption, LTNE provides more accurate predictions, particularly when the solid-to-fluid thermal conductivity ratio is high. The validity of the model is confirmed through comparison with two limiting cases: a hollow tube and a fully filled tube. Owing to the closed-form nature of the solution, system performance can be evaluated continuously over the entire porosity range of (0,1).

The results show that, as the dimensionless interfacial radius increases, the friction factor decreases and varies inversely with the Reynolds number. The Nusselt number exhibits a non-uniform dependence on porosity, and for each pore density there exists an optimal porosity that maximizes heat transfer; for ω=30 PPI, this optimum is obtained at ε=0.87. In addition, the dependence of Nu on the interfacial radius is nonlinear, and in some ranges the thermal performance becomes even weaker than that of the hollow tube. Overall, the findings indicate that a partially filled configuration, with proper selection of geometric and morphological parameters, can achieve an effective balance between heat transfer enhancement and pressure-drop control.