Accession Number : AD0759209

Title :   Wind Tunnel Feasibility Study of Aerodynamic Reefing of Subsonic Parachutes.

Descriptive Note : Final rept. Feb 70-Aug 72,

Corporate Author : MINNESOTA UNIV MINNEAPOLIS DEPT OF AEROSPACE ENGINEERING AND MECHANICS

Personal Author(s) : Heinrich,Helnut G. ; Noreen,Robert A.

Report Date : MAY 1973

Pagination or Media Count : 26

Abstract : The inflation characteristics of solid flat circular model parachutes with stiffness indices in the order of 1.17 and various annular slots were studied in a wind tunnel at velocities up to 265 fps. The amount of the geometric porosity was varied as well as the location of the annular slots. It was found that at a speed of 250 fps models with geometric porosities up to 18% inflated immediately, with porosities between 18% and 28% the models showed random inflation and collapsing, and at porosities of 28% and higher squidding or aerodynamic reefing was observed. The location of the slots did not influence the inflation characteristics significantly. The critical speed was established for a number of models; however, the conclusion was reached that more efforts have to be made in order to understand the mechanics of squidding to be able to take advantage of the principle of aerodynamic reefing for full scale design. (Author)

Descriptors :   (*PARACHUTES, AERODYNAMIC CONFIGURATIONS), AERODYNAMIC SLOTS, FEASIBILITY STUDIES, WIND TUNNEL MODELS, VELOCITY

Subject Categories : Gliders and Parachutes

Distribution Statement : APPROVED FOR PUBLIC RELEASE