Submunitions should exhibit optimum terminal performance at target end when released from certain pre-determined height. Selection of an optimum height of release of the submunitions depends on the terminal parameters...Submunitions should exhibit optimum terminal performance at target end when released from certain pre-determined height. Selection of an optimum height of release of the submunitions depends on the terminal parameters like forward throw, remaining velocity, impact angle and flight time. In this paper,the effects of initial firing conditions and height of release on terminal performance of submunitions discussed in detail. For different height of release, the relation between range and forward throw is also established & validated for a number of firing altitude and rocket configurations.展开更多
In any armament system,projectile yaw during flight is undesirable because it affects range.For drag calculation,the area of the cross section of the projectile perpendicular to the air flow,called reference area,is u...In any armament system,projectile yaw during flight is undesirable because it affects range.For drag calculation,the area of the cross section of the projectile perpendicular to the air flow,called reference area,is used.If yaw angle is zero,reference area depends only on the diameter of the projectile.When yaw angle is nonzero reference area is more;resulting in more drag.For a given projectile,a mathematical relation between yaw angle and corresponding reference area can be established.This paper proposes a method to estimate yaw angle at each point on the trajectory from the flight data.The method uses extended Kalman filter(EKF)and system dynamics is modeled using modified point mass trajectory model.At each instant reference area is estimated using EKF.This area is mapped to yaw angle through pre-established mathematical relation.The method is validated using simulation.In special cases,the results are validated with the help of actual flight data.The proposed method is effective and can be used for indirect measurement of yaw angle or angle of attack.展开更多
文摘Submunitions should exhibit optimum terminal performance at target end when released from certain pre-determined height. Selection of an optimum height of release of the submunitions depends on the terminal parameters like forward throw, remaining velocity, impact angle and flight time. In this paper,the effects of initial firing conditions and height of release on terminal performance of submunitions discussed in detail. For different height of release, the relation between range and forward throw is also established & validated for a number of firing altitude and rocket configurations.
文摘In any armament system,projectile yaw during flight is undesirable because it affects range.For drag calculation,the area of the cross section of the projectile perpendicular to the air flow,called reference area,is used.If yaw angle is zero,reference area depends only on the diameter of the projectile.When yaw angle is nonzero reference area is more;resulting in more drag.For a given projectile,a mathematical relation between yaw angle and corresponding reference area can be established.This paper proposes a method to estimate yaw angle at each point on the trajectory from the flight data.The method uses extended Kalman filter(EKF)and system dynamics is modeled using modified point mass trajectory model.At each instant reference area is estimated using EKF.This area is mapped to yaw angle through pre-established mathematical relation.The method is validated using simulation.In special cases,the results are validated with the help of actual flight data.The proposed method is effective and can be used for indirect measurement of yaw angle or angle of attack.
