Development of a Scale Model Parachute Wind Sensor
Abstract
A scale model parachute GPS wind sensor is to be designed that will follow the same trajectory as that of a full size PAD payload. This will allow the wind field to be measured where it is most needed, along the descent path of the payload. In actual operation the scale model sensor would be released shortly before the payload, the wind field calculated in real time during descent, and used in the CARP algorithm to calculate the payload release point. In order for the scale model parachute system to follow the same trajectory as the full size payload system several scaling parameters must be analyzed. A necessary condition that the airflow around scale model system. Since the flow around an object depends upon Reynolds and mach numbers, a change in these parameters could cause the airflow to change and thus the drag coefficients to change between the scale model and full size systems. The mach number will remain the same for the two systems because the systems are designed to maintain the same trajectory. The Reynolds Number however, will be necessity vary because of the difference in the dimensions of the two systems. Thus it must be established whether the variation in Reynolds number over the range that occurs between the full and scaled systems significantly changes the drag coefficient of the systems. Other parameters that may change the relative airflow between the two systems are the porosity of the parachute fabric, the mass of each systems, the length of the tether lines, and the size air passage opening in the center of each parachute. Each of these parameters is addressed in the following analyses.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1998
- Accession Number
- ADA376978
Entities
People
- James K. Luers
Organizations
- University of Dayton