Computational analysis of external heat transfer for a tubular Stirling convertor

•Stirling convertor and combustion burner interface analysis.•The flow distribution and heat transfer characteristics of the combustion gas.•Novel flow guides and a diffuser plate greatly improve flow dynamics and heat transfer.•Additively manufactured Stirling heater head. Stirling convertors are an ideal choice for use in numerous energy conversion applications owing to their simplistic design, fuel independence, and robustness. The use of additive manufacturing allows for significant improvements in the overall system efficiency by removing the design limitations of traditional manufacturing techniques. This allows for the design of a novel burner–heater head interface that can vastly improve the external heat transfer. A numerical analysis of the combustion flow over an additively manufactured tubular heater head was conducted. It was shown that the use of flow guides improves the velocity distribution of the combustion gases over the heat acceptor tubes. Additionally, the use of a diffuser plate can be employed to further improve the heat transfer. The developed model can be used further to optimize the overall design of the heat acceptor, regenerator, and heat rejecter.