Utilization of additive manufacturing in hybrid rocket technology: A review

Abstract The focus of this review is to collect and compare research studies on hybrid rocket fuels and components produced via additive manufacturing. The use of hybrid rocket propulsion for launching applications is limited due to its inherently low regression rate and actual specific impulse. To address these limitations, various additive manufacturing methods have been employed so far to fabricate fuel grains with complex port geometries or composite fuel grains possessing intricate shaped, printed scaffolds into which a second fuel material is incorporated. In addition to the fuel grains, additive manufacturing technology has also proven to be beneficial for fabricating a considerable number of hybrid rocket components, thereby reducing the part count, production time and cost. In this review, the rationale, types of the materials used, methods and comparison of performance data are presented. Future directions that use additive manufacturing to enhance hybrid rocket propulsion are also provided.