Metal foam fillings provide a ‘cool’ thermal management solution

High-temperature aerospace structures often have little room to spare. Panels and liners in aircraft combustors or other high-heat-flux regions must be light and thin, yet still able to support mechanical loads and remove heat. Xiao et al. studied one potential design: an ultralight corrugated-core sandwich structure (CSS), made from aluminum alloy or steel, filled with an open-cell metal foam to combine load bearing with flow-through active cooling.

When comparing an unfilled CSS, a CSS filled with smooth-surfaced aluminum foam, and a CSS filled with rough-surfaced aluminum foam using pore-scale simulations, the researchers found the foam-filled panels combine structural support and active cooling within a small sandwich volume. The corrugated core provides the primary load-bearing framework, while the metal foam adds internal support without requiring a large increase in size. At the same time, the foam skeleton helps conduct heat away, and its open pores disturb the coolant flow and promote mixing between fluids at different temperatures. Thanks to its larger surface area and stronger interaction with the surrounding fluid, the rough-surfaced foam has the best heat transfer performance.

The foam fillings involve a tradeoff: Though the foam increases the pressure drop across the panel, potentially raising the pumping-power cost, the heat-transfer improvement could outweigh this penalty.

“Although the presence of metal foam leads to an increase in pressure drop, its overall thermal performance remains superior to that of the unfilled corrugated-core sandwich structure,” said author Tian Xiao.

The group plans to test 3D-printed foam-filled CSS structures and optimize key parameters such as foam porosity, surface morphology, and core geometry. Such structures could eventually serve as lightweight, compact, load-bearing cooling panels or liners for high-heat-flux regions of aircraft and spacecraft.

“This structure can serve as an integrated thermal management and load-bearing system, suitable for components requiring both temperature control and structural support, such as jet blast deflectors and hangar doors in aircraft carriers,” Xiao said.

Source: “Pore-scale simulation of ultralight sandwich panel filled with metal foam for simultaneous load bearing and active cooling,” by Tian Xiao, Chengxu He, Youruo Wu, Yuanji Li, Liu Lu, Zengshen Yue, Xiaohu Yang, and Tian Jian Lu, MechanoEngineering (2026). The article can be accessed at https://doi.org/10.1063/5.0330597 .