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Accession Number:
AD0831048
Title:
THE PREDICTION OF MATERIAL TEMPERATURES ON WOVEN RETARDATION DEVICES
Descriptive Note:
Final rept. Aug 1966-Sep 1967
Corporate Author:
MINNESOTA UNIV MINNEAPOLIS HEAT TRANSFER LAB
Report Date:
1968-03-01
Pagination or Media Count:
84.0
Abstract:
The primary purpose of this report is to present analytical techniques for the prediction of instantaneous parachute temperatures for any prescribed flight condition and history of operation. Sample calculations are presented which illustrate the technique by comparing measured parachute temperature histories with several predictive techniques. A variety of exact, transient heat conduction solutions are included for a cylindrical geometry which cover a range of trajectory possibilities. This was done because the transfer of heat to a conventional fabric or coated-fabric parachute is governed primarily by the large resistance to heat conduction into the interior. The commonly used infinite thermal conductivity case is shown to produce surface temperatures which fall considerably below the surface temperatures predicted by more exact complete energy balances. For the extreme applied heat flux case atmospheric entry, internal temperatures are accurately predicted by assuming the wall temperature instantaneously assumes a steady state, radiation equilibrium value q sub w 0 and internal conduction governs the process. An approximate method is presented for the calculation of parachute fabric temperatures when both the internal and external resistances to the flow of heat are of importance. The results are compared with flight test data on a full- scale parachute. Author
Distribution Statement:
APPROVED FOR PUBLIC RELEASE
