Numerical Trajectory Simulation of a Dual Mode Mortar Round

Abstract

The Dual Mode Mortar Round (DMMR) presented in this paper is an answer to the need for a high precision low cost weapon. Its dual mode GPS and Strap-down Semi-Active Laser (SAL) capabilities can provide brigade combat teams with indirect precision fires at extended ranges. A high fidelity computer simulation is one of the key components in the development of the DMMR. Due to canard vortex shedding, the tail section is allowed to spin freely, subject of course to frictional constraint forces. This paper summarizes the mathematics of the 7 dof model and illustrates the derivation of the friction forces and moments to which both front and aft sections are subject. 1 Nomenclature aA = acceleration @ point A (m / sec 2 ) aB = acceleration @ point B (m / sec 2 ) CD_tail = drag coefficient of tail Clp = roll moment damping coefficient Clpfront = roll moment damping coefficient of front section Clptail = roll moment damping coefficient of tail section CM(�,�,Ma,�u) = pitching moment coefficient Cn(�,�,Ma,�u) = yawing moment coefficient CN (�,�,Ma,�u) = normal force coefficient CNfront(�,�,Ma,�u) = normal force coefficient of fore section CR_front(�,�,Ma,�u) = roll moment coefficient of tail section CR_tail(�,�,Ma,�u) = roll moment coefficient of tail CX(�,�,Ma,�u) = drag coefficient CY(�,�,Ma,�u) = side force coefficient Cxfront(�,�,Ma,�u) = drag coefficient of fore section Cyfront (�,�,Ma,�u) = side force coefficient of fore section Cxtail(�,�,Ma,�u) = drag coefficient of tail section Cytail (�,�,Ma,�u)