Performance parameters enhancement of a thermoelectric generator by metal foam in exhaust automotive lines

•Numerical study on a TEG in automotive exhaust line with metal foam is provided.•Hot surface temperature of the TEG increases increasing the foam thickness.•The system efficiency enhances increasing the mass flow rate and the foam thickness.•The useful converted energy presents maximum values for metal foam thickness ≥5/8.•Electric and pumping power ratio reaches a maximum for foam thickness ratio of 0.4.