Design, Simulation, and Experimental Testing of Humanitarian Aid Airdrop Micro Packages

Abstract

Conventional airdrop methods for humanitarian aid and emergency relief require dropping heavy payloads far away from the intended recipients. Currently, there are a number of issues with this method of delivery. Because supplies are distributed by just a few large crates dropped on or near the location of those requiring relief, there is not only risk of injury upon being struck by one of these large crates, but it is also common for the distribution of supplies to be inhibited by adversaries. Thus, in an effort to reduce or eliminate the occurrence of such difficulties, a safer, more effective means of dropping and distributing humanitarian aid is necessary. The development of small sized packages of supplies that can be dispersed directly above a populated area with minimal risk of human injury is essential to ensure safe, timely, and effective distribution of aid. The research reported here explores several proposed packaging designs of individual food and water rations to identify possible methods to deploy emergency relief in a manner consistent with the previously stated requirements. With a combination of flight dynamic simulation, wind tunnel testing, and flight testing, promising package designs that meet impact requirements are identified. NomenclatureC = aerodynamic force or moment coefficient, denoted by subscript , , = unit vectors denoting the axes of a reference frame [I] = total body mass moment of inertia matrix (kg-m 2 ) A = reference area (m 2 ) F s = cushion spring force (N) g = gravitational acceleration (m/s 2 ) k s = cushion spring stiffness (Pa/m) L, M, N = moment components in the body reference frame (N-m) m= total body mass (kg) p, q, r = angular velocity components of the body frame with respect to the body frame (rsd/s) q 0 , q 1 , q 2 , q 3 = quaternion parameters denoting the orientation of the body frame relative to the inertial frame R = sphere radius (m) r x , r y , r z = body frame components of a position vector from center of gravity to a point of interest (m) s = cushion thickness (m) SL, BL, WL = distances along the station, butt, and water lines from the body frame origin (m) [T BW ] = rotation matrix from the body to the wind reference frame [T IB ] = rotation matrix from the inertial to the body reference frame 2 u, v, w = velocity components of the mass center in a body reference frame (m/s) V air = air velocity magnitude relative to the body center of gravity (m/s) V imp = cushion impact velocity magnitude (m/s) V w = horizontal wind velocity magnitude with respect to the inertial frame (m/s) x, y, z = inertial positions of the body mass center (m) X, Y, Z = force components in the body reference frame (N) x imp = cushion impact deflection (m) φ, θ, ψ = Euler roll, pitch, and yaw angles of the body frame relative to the inertial frame (rad) ψ w = wind heading from North (rad) Subscripts * 0 = pertaining to the initial state * A = aerodynamic forces and moments acting on the attachments * air = air velocities relative to the center of gravity in the body frame * B