Enhancement of Hybrid Fuel Regression Rate Using a Bluff Body

Abstract

In this paper, an attempt is made to increase the regression rate of the hybrid fuel (paraffin wax) using a hemispherical bluff body placed near the head end of the motor. The oxidizer used for the present study is gaseous oxygen. The results show that the use of a bluff body increases the regression rate by around two times at the higher () and by around three to four times at the lower (). This increase in regression rate diminishes as the of the motor is increased from 9 to 27, whilst still being higher than the case without bluff body. The bluff body was seen to increase the regression rate even at a port diameter, which was four times the initial port diameter of 15 mm. The was nearly constant () for the case with the bluff body, whilst for the case without the bluff body, it increased from 1.5 to 2 during an operation time of 4.5 s. In addition, the port diameter after combustion was nearly uniform from the head end to the nozzle end as compared to the case when no bluff body was used, thus minimizing the sliver losses.