Experiment and numerical research on regression rate of hybrid rocket motor with single-port wagon wheel fuel grain

This paper focuses on the research on regression rate of hybrid rocket motor with single-port wagon wheel fuel grain. Both experiment and numerical investigations are carried out to study the three-dimension regression rate of hybrid rocket motor on several characteristic points. A laboratory 500 N-class firing test of hybrid rocket motor with single-port wagon wheel fuel grain has been conducted on the standard ground experimental system. The 98% hydrogen peroxide oxidizer and hydroxyl terminated polybutadiene based fuel are adopted as pro-pellants. The digital image processing of three-dimension regression rate is carried out, and a post-processing software has been developed to calculate the time-averaged three-dimension distribution of regression rate after the firing test. Three-dimensional numerical simulations with gaseous combustion considered are carried out to study the axial distribution of regression rate. The results of digital image processing manifest that the average regression rates of the middle position of wagon wheel spokes is higher than those in the slot of wagon wheel. A good agreement exists between the calculated regression rate from numerical simulation and the experimental results conducted by computed tomography scanning. The comparison results show that the digital image processing is potentially an effective tool for investigating and predicting the three-dimension regression rate of hybrid rocket motor with single-port wagon wheel fuel grain.