Engineering topics
Publications and source records attributed to Udlock, D. E..
Burn-test apparatus made from conductive metal grid and indicator lamp monitors release of conductive carbon fibers from specimen of carbon-reinforced composites exposed to flame. Procedure is more sensitive than photographing or physically trapping and counting fibers.
Storage of solid propellants in either a dry or a vacuum environment causes a significantly greater increase in the propellants' modulus and maximum tensile strength than does ambient storage. It is postulated that these physical property changes can be attributed to the effect trace amount of moisture has on the bond between the propellants' binder and oxidizer.
A test program is described which determines the extent of physical property changes that result from extended space exposure. Primary emphasis was placed on determining the effects of space vacuum. Solid propellants were stored and their physical properties tested in a vacuum and in a dry environment. The storage caused significantly greater increases in the propellants' modulus and maximum tensile strength than occurred in parallel ambient stored samples. The data indicate that the loss of trace amounts of residual moisture from cured propellant is the apparent cause of the observed propellant property changes. Therefore, initial screening tests were carried out under dry storage conditions. Upon completion of the dry storage tests, appropriate propellant samples are exposed to an actual space environment using the Long Duration Exposure Facility (LDEF).
A brief investigation of the combustion characteristics of a solid propellant containing a binder which chars, as opposed to melting or volatizing, has been made. The burning rate of the propellant with the charring binder was significantly higher than similar propellants containing non-charring binders. High speed motion pictures of the burning propellant showed that the aluminum burned on the regressing surface, rather than a short distance from it as is typical with composite propellants.
Low modulus solid propellants family for low thrust-to-mass ratio fully case bonded end-burning motors, using polymer network theory for binder formulation
Chain and stereo isomers of dipropylene glycol analyzed by gas liquid partition chromatography