Fluid-structure interaction simulation of parachute dynamic behaviour

The work presented concerns the numerical simulation on the dynamic behaviour of full size parachute models using a non linear explicit Fluid-Structure Interaction method. As a previous result of the partnership between ENSICA and CEV/TL, some partial solutions to model the parachute, the suspension lines, the surrounding air, and the coupling phenomenon were first determined. Validation criteria used for the presented results are the drag force, the kinematics and pressures in the fluid domain known from previous simulation work, and the inflated shape of a known cross parachute. These results, though inaccurate, were a major marker pole on the way to parachute opening simulation which requires many intermediary checks and developments. Some specific phenomena, like those related to the apparent mass increase during the parachute opening, will be correctly simulated when the basics of FSI are mastered well. The comparison between the obtained results and experimental measures allowed us in 2004 to propose the development of new features in the numerical methods of the hydrodynamic explicit code LS-DYNA, especially a new coupling method for air vs. porous fabric. The current achievement is also considered as a good basis for the coming simulations of opening and full descent

Four-Powers Long Term Technology Projects: "Airflow Influence on Airdrop" and "2nd Precision Airdrop Improvements"

The Four-Powers Air Senior National Representative (ASNRs) Long Term Technology Projects (LTTPs) related to airdrop research include both the Airflow on Aircraft (AIA) technical Group (TG) and the 2nd Precision Airdrop Improvements (PAIc) TG. The TG’s are made up of Subject matter experts from France (FR), Germany (GE), The United Kingdom (UK), and the United States (US). This paper will provide an overview of each TG’s objectives, work plans, results to date, and future activities. In addition, under the PAIc activities, the paper will describe the status of a planned North Atlantic Treaty Organization (NATO) Precision Airdrop Capabilities Demonstration (PACD)