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Mcgarvey, J. F.

Publications and source records attributed to Mcgarvey, J. F..

4 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

Theory of prediction of solar eclipse as observed from a sounding rocket using rocket trajectory and eclipse ephemeris

The present paper deals with the problem of determining various solar eclipse variables as observed from a sounding rocket for various rocket trajectories. By applying the methods described to a set of trajectories, a set of boundary conditions, launch azimuth, quadrant elevation, and launch time may be selected to optimize any aspect of eclipse observation within the constraints imposed by rocket performance.

Mcgarvey, J. F.↗
NASA NTRS1977

Nonlinear stress waves in a perfectly flexible string

This paper discusses nonlinear stress-wave propagation in a perfectly flexible string obeying a quasilinear (rate-dependent) constitutive equation. Wave speeds and compatibility relations valid along various families of characteristics were determined. It was shown that the compatibility relations associated with the transverse as well as the longitudinal waves readily yield a physical interpretation when they are expressed in suitable variables and in vector form. Coding based on the present information was completed for the machine solution of a class of mixed initial- and boundary-value problems of practical interest. Computer simulation of the stress-wave interaction in the 40-foot lanyard in the Arcas 'Rocoz' system during deployment was carried out using a stress-strain relation for nylon at the strain rate of 30/second. A method for estimating the maximum tension and strain in a string during the initial loading phase is proposed.

Fan, D.-N.↗
NASA NTRS1973

Recovery of sounding rocket payloads by center-of-gravity position control.

A computerized procedure has been developed to predict dynamic pressure at parachute deployment altitude. Inputs to the program are payload geometry, center-of-gravity position, velocity, and altitude at start of reentry. Payload is assumed to be trimmed, and potential and cross-flow drag theory is used to compute trim angle-of-attack and trim drag coefficient as a function of free-stream Mach number. The computations involve only simple geometric quantities and closed-form equations. Payload flight path is assumed to be vertical, and equations of motion of the payload are integrated from start of reentry to chute deployment altitude.

Mcgarvey, J. F.↗