Characterization of Heat and Momentum Transfer in Sintered Metal Foams

Abstract

In this study, metal foams made by the Slip Reaction Foam Sintering (SRFS)‐process are investigated concerning their thermophysical and permeability properties. Since the foam is to be applied as a functional and structural element in the effusion air cooling system of a stationary gas turbine combustion chamber, these properties are of major interest for the calculation of the temperature distribution inside the combustion chamber walls, which may be critical for the employed materials. Experimental set‐ups are presented, which are used to determine permeability, the volumetric heat transfer coefficient and the effective thermal conductivity. The results are presented for a wide range of foam materials. Porosity as well as the basic metal powder and the manufacturing parameters are varied. The influence of these parameters on the measured quantities is discussed. Thermal conductivity data are determined at temperatures of up to 1200 K. The obtained volumetric heat transfer coefficients are transferred to Nusselt–Reynolds plots, which allow generalization to the high temperature and high pressure regime. Correlations between the heat transfer properties and the permeability data are made. Using the acquired experimental data, a proposal is made for the calculation of the inner surface temperature of the combustion chamber as well as the temperature distribution inside the chamber wall, which consists of a structural element, the metal foam and a thermal barrier coating, equipped with laser drilled micro‐holes.

Porous Metals and Metallic Foams: Current Status and Recent Developments

“…This combination of properties makes them attractive for various thermal applications (heat exchangers, heat sink, heat pipes). Various research centres are presently working on the characterisation [121][122][123][124][125][126][127] and modelling [128,129] of heat transfer and thermal exchanges in metal foams with various structures.…”

Exceptional Performance of Flame-Retardant Polyurethane Foam: The Suppression Effect on Explosion Pressure and Flame Propagation of Methane-Air Premixed Gas

“…In addition to the aforementioned explosion suppression technologies, porous media have been employed for explosion protection in fuel and oil storage tanks. Porous media, such as wire mesh [23], metal foam [24][25][26][27], and non-metal foam [28][29][30], have been investigated for explosion protection in fuel and oil storage tanks. To explore the quenching mechanism of porous media on a gaseous deflagration, researchers designed porous media with different geometric parameters and found that smaller pore sizes enhanced the flame quenching performance [31].…”