Design, manufacture, and analysis of metal foam electrical resistance heater

This paper presents a novel concept using the radial heating element made from porous Fe–Cr–Al metal foam in an air heater. Electrical resistance heating has been used extensively to convert the electrical energy into thermal energy. An analytic heat transfer model is first developed to estimate dimensions of the heating element. Four prototype Fe–Cr–Al metal foam electrical heaters with different levels of porosity and density are built. A more detailed computational fluid dynamics modeling of prototype heaters to include the temperature loss to the surroundings is developed. Experiments are conducted to evaluate the effects of airflow rates and electrical current and measure the change of air inlet and outlet temperatures. The experimental temperature measurements show reasonably good agreement with modeling predictions. Finally, improvements to the initial concept are discussed.