THE PARACHUTE SYSTEM WITH THE ELASTIC LINK AND THE LOAD DIVIDED INTO TWO PARTS AS A TANDEM

Abstract

The article suggests a new type of the parachute system (PS). Its distinctive feature is the presence of an elastic link (EL) for attaching the cargo to the parachute, and the cargo itself is divided into two parts, m1 and m2, comparable in weight and suspended one under the other. The cargo is connected by a cable through the cable length control mechanism. PS in flight consists of a parachute, stretched EL, cargo m1, the cable length control mechanism, cable, cargo m2. The main feature of this type of PS is the ability to provide low dynamic overloads of m1 cargo during the entire flight, including landing. For a soft landing of m1 cargo, it is necessary to choose the main parameters of the PS correctly: the parachute area, the EL stiffness, the weight of m1 and m2 cargo, the length of the cable. To confirm the efficiency and feasibility of the proposed concept, an experimental PS with a flight mass of m ≈ 10 kg was designed, prepared and tested. The parachute is made of zero porosity fabric, its area is S = 2.2 m² It has a cylindrical skirt that is used to give stability to the PS in flight. As an EL a silicone tube is used with the length of l₀ = 6 m when unstretched, but in flight under the weight of cargo ml and m2 it is stretched to l₀ + Δl ≈  17 m. The mass of the cargo ml is m₁ - 5.5 kg, m2 cargo has a mass of m₂ ≈  4.5 kg. To raise the PS a two-seat hang-glider was used. The drop occurred from the height of H ≈  200 m. The rate of decent before landing was Ve = 8...9 m/s. The analysis of the final records of dynamic overloads shows that during the entire flight, including landing, the total cargo overload ml did not exceed n = 5. Thereby operability, feasibility and the declared properties of the offered type of PS are confirmed.