Regression Rates of Non-liquefying Fuels in a Hybrid Rocket Engine at Atmospheric Pressure

Hybrid rocket propulsion systems offer many advantages including throttling capabilities and safety. This study investigates the regression rates of non-liquefying fuels in hybrid rocket engines operating under atmospheric pressure conditions with the purpose to investigate the effects of chamber pressure and establishing a pure baseline database. Traditional polymeric fuels were the main focus of the study. The three fuels studied were high density polyethylene (HDPE), polypropylene (PP), and polymethyl methacrylate (PMMA). Regression rates were measured and the a and n experimental constants were obtained. Regression rate correction was also applied. A comparative analysis was per-formed, comparing the findings with existing literature data. Discrepancies were observed, highlighting the influence of external factors and chamber pressure on regression rates. The findings show discrepancy between the regression rates of fuels under different chamber pressures when compared to other studies, providing valuable insights for fuel se-lection and mission design. Moreover, the study emphasizes the im-portance of establishing pure regression rate databases to facilitate accurate comparisons and optimize the performance of hybrid rocket engines.