Scale-up validation of hydrogen peroxide/high-density polyethylene hybrid rocket with multiport solid fuel

A feasibility study related to the scale-up of solid fuel with multiport was performed using the regression rate equation derived from a laboratory-scale hydrogen peroxide (H₂O₂) hybrid rocket using a single-port solid fuel. First, a 250-N-class hybrid rocket using a single-port solid fuel was designed and experiments were conducted to derive the regression rate equation. Based on the derived equation and fuel design method for a 250-N-class hybrid rocket, a multiport solid fuel of a 2500-N-class hybrid rocket was designed. To evaluate the validity of the derived regression rate equation and the scale-up potential of solid fuel, not only experimental tests but also an analytical estimation was performed based on the derived equation. The design method using both experimental and analytical approaches was useful in determining the accuracy and effectiveness of the derived equation. It was useful in the scale-up design process of a rocket in a different scale and with a different type of feeding system. More than 90% of the design thrust was confirmed to be produced from the scale-up H₂O₂/high-density polyethylene hybrid rocket during the blowdown mode operation. The maximum differences of the final port diameter and regression rate between the analytical estimation and experiments were found to be 2.6 and 8.4%, respectively. As a result, the design and estimation of multiport solid fuels in a different scale based on the regression rate equation derived from the H₂O₂ hybrid rocket with a single-port solid fuel were confirmed as sufficiently feasible.