AN INNOVATIVE STABILIZER UNIT DESIGNFOR TUBE LAUNCHEDARTILLERY ROCKET TO IMPROVE DYNAMIC STABILITY

摘要

Stabilizer unit of any artillery rocket is very important part, which provides stability to the rocket during flight. Conventionally tube launched rocket has curved wrap around fins (WAF) stabilizer unit .Although these curved WAF provide maximum packing efficiency in given space envelop but it also possess excessive out-of-plane moment (C_(nα)) during flight which may lead to dynamic instability of the rocket. In the literature, work has been carried out to reduce out-of-plane moment generated by Curved WAF by reducing curvature, cant angle and span. By using these methods out-of-plane moment reduces but does not become negligible, which may not guarantee dynamic stability during flight. In the present work, stabilizer unit is designed with flat wrap around fins (WAF). Necessary modifications are done in the fin and fin cylinder design to pack rocket with flat WAF inside launch tube. Computational fluid dynamic (CFD) is used to find out aerodynamic coefficients of the rocket. A comparative study has been carried out to find out the aerodynamic behavior of same rocket with curved and flat WAF. It is found that with flat WAF chances of occurrence of out-of-plane moment reduced drastically. Hence, it is recommended to use Flat WAF for tube launch rocket to avoid any possibility of occurrence of dynamic instability during flight.