Based on the stability theory, numerical simulations and theoretical calculations are performed for a projectile with wrap-around fins. Its stability is analyzed and the flow field is simulated with computational flui...Based on the stability theory, numerical simulations and theoretical calculations are performed for a projectile with wrap-around fins. Its stability is analyzed and the flow field is simulated with computational fluid dynamics method. Consequently, the pitching moment coefficient of the projectile is further investigated under the conditions of Mach number ranging from 0.3 to 0.8, attack angle from 0 to 8° and yaw angle from 0 to 4°. A trajectory equation is established and its trajectory characteristics are also explored. All the results of theoretical analysis, numerical simulation and trajectory equation agree well with each other, which indicates the projectile is flying steadily at the given conditions. These results provide an effective way for judging the stability of the projectile with wrap-around fins.展开更多
The transonic-supersonic wind tunnel experiment on the aerodynamics of the rockets and missiles that have four, six, eight flat or wrap-around fins is introduced. The experimental results show, while M∞〈2.0, with th...The transonic-supersonic wind tunnel experiment on the aerodynamics of the rockets and missiles that have four, six, eight flat or wrap-around fins is introduced. The experimental results show, while M∞〈2.0, with the increase of the fins＇number, the derivative of lift coefficient is increasing, the pressure center is shifting backwards, and the longitudinal static stability is augmenting. On the contrary, while the Mach number exceeds a certain supersonic value, the aerodynamic effectiveness of the eight-fin missiles would be lower than that of the six-fin missiles. For the low speed short-range missiles, by adopting six, eight or ten flat fins configuration, the lift effectiveness can be greatly increased, the pressure center can be shifted backwards, the static and dynamic stability can be obviously enhanced. For the high speed long-range large rockets and missiles launched from multi-tube launcher, the configuration adopting more than six fins can not be useful for increasing the stability but would make the rolling rate instable during the flight.展开更多
Both the asymptotical stability criterion and the bounded stability criterion of the coning motion for wrap around fin(WAF) rockets are proposed through the analy-sis of coning motion equations,which can be easily use...Both the asymptotical stability criterion and the bounded stability criterion of the coning motion for wrap around fin(WAF) rockets are proposed through the analy-sis of coning motion equations,which can be easily used to determine the exis-tence of the coning motion during the rocket design. The correctness of the crite-rions is verified by mathematical simulation examples of a WAF rocket with differ-ent setting angles. It is also found that the setting angle of WAF has great effects on the rolling moment and side moment of the rocket.展开更多
基金the National Natural Science Foundation of China (10572026)
文摘Based on the stability theory, numerical simulations and theoretical calculations are performed for a projectile with wrap-around fins. Its stability is analyzed and the flow field is simulated with computational fluid dynamics method. Consequently, the pitching moment coefficient of the projectile is further investigated under the conditions of Mach number ranging from 0.3 to 0.8, attack angle from 0 to 8° and yaw angle from 0 to 4°. A trajectory equation is established and its trajectory characteristics are also explored. All the results of theoretical analysis, numerical simulation and trajectory equation agree well with each other, which indicates the projectile is flying steadily at the given conditions. These results provide an effective way for judging the stability of the projectile with wrap-around fins.
文摘The transonic-supersonic wind tunnel experiment on the aerodynamics of the rockets and missiles that have four, six, eight flat or wrap-around fins is introduced. The experimental results show, while M∞〈2.0, with the increase of the fins＇number, the derivative of lift coefficient is increasing, the pressure center is shifting backwards, and the longitudinal static stability is augmenting. On the contrary, while the Mach number exceeds a certain supersonic value, the aerodynamic effectiveness of the eight-fin missiles would be lower than that of the six-fin missiles. For the low speed short-range missiles, by adopting six, eight or ten flat fins configuration, the lift effectiveness can be greatly increased, the pressure center can be shifted backwards, the static and dynamic stability can be obviously enhanced. For the high speed long-range large rockets and missiles launched from multi-tube launcher, the configuration adopting more than six fins can not be useful for increasing the stability but would make the rolling rate instable during the flight.
文摘Both the asymptotical stability criterion and the bounded stability criterion of the coning motion for wrap around fin(WAF) rockets are proposed through the analy-sis of coning motion equations,which can be easily used to determine the exis-tence of the coning motion during the rocket design. The correctness of the crite-rions is verified by mathematical simulation examples of a WAF rocket with differ-ent setting angles. It is also found that the setting angle of WAF has great effects on the rolling moment and side moment of the rocket.
