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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Solid viscoelastic cylinder bonded to thin elastic casing, analyzing normal and tangential stresses for stress and displacement frequency responses in forced transverse vibration
Adhesive debonding in case-bonded solid propellant rocket motors, describing stress analysis and interfacial surface energy measurement
Nonmagnetic hermetically sealed battery case made of epoxy resin and woven glass tape for use with electrochemical cells in spacecraft
Method for shaping regeneratively cooled rocket motor casing having minimum thickness at each channel cross section
Regeneratively cooled rocket motor casing with tapered channels to insure minimum thicknesses at each channel cross section for necessary strength requirements
Payload/spent rocket engine case separation system
Permanently magnetized ion engine casing construction for use in spacecraft propulsion systems
Sealed electrochemical cell with flexible casing for varying electrolyte level in cell
Test description and results for high Mach number transonic fan stages to determine range and distortion tolerance for various rotor tip casing treatment configurations
Tabulations of blade element and circumferential distortion flow data in tests of high Mach number transonic fan stages with various rotor tip casing treatment configurations
Low modulus solid propellants family for low thrust-to-mass ratio fully case bonded end-burning motors, using polymer network theory for binder formulation
Organiation and presentation of data pertaining to design of solid propellant rocket engine cases are discussed. Design criteria are presented in form of monograph based on accumulated experience and knowledge. Improvements in reliability, cost effectiveness, and engine efficiency are stressed.
The effect of casing boundary-layer removal on noise produced by a turbofan rotor was measured. The outlet guide vanes were removed for these tests. A comparison was made between the noise measurements when the boundary layer was bled off and under zero bleed conditions. When the boundary layer was removed, overall sound pressure level was reduced 2 dB with moderate blade loading and 3 dB with heavier blade loading. An analysis of the changes in the spectral density with bleed is presented.
A worst case analysis is reported on the safety of time watch movements for triggering explosive packages on the lunar surface in an experiment to investigate physical lunar structural characteristics through induced seismic energy waves. Considered are the combined effects of low pressure, low temperature, lunar gravity, gear train error, and position. Control measures constitute a seal control cavity and design requirements to prevent overbanking in the mainspring torque curve. Thus, the potential hazard is reduced to safety negligible.
Demonstration that accurate solutions to the integral equation or to the extremal function can be easily obtained by the variational method in many cases when a stepwise constant function is used for the trial function. The evaluation procedure is simple and straightforward; integrals of the kernel function can be evaluated analytically; the method provides, when the solution involves singularities, the best mean value across the singularity; the results are accurate in both the detailed physical quantities and their averages; the resultant solution can be further integrated analytically over the parameters associated with the problem; and the method can be readily applied to nonlinear integral equations.
Extension of Allen and Wing's (1970) previous work on problems of transport in periodic media to the matrix case. A method in the form of a complete set of equations is presented that may be used without any further analytical work by investigators interested in computing solutions to problems of the type the method is designed to handle. All the formulas have been checked out numerically, and their effectiveness is demonstrated by numerical examples.
The problem of the transmission of sound in a duct with very thin shear layers at the walls is treated by an inner expansion method. The results show that the formulation of the problem of the transmission of sound in a duct with a shear layer at the wall converges, in the case of a vanishingly thin shear layer, to the formulation of the same problem when uniform flow is assumed and the wall boundary condition is that of continuity of particle displacement.
A review of exact techniques for determining the surface of a three-dimensional perfectly conducting body is given, followed by some new results on the uniqueness question concerning the number of measurements that may be required to explicitly determine the surface of the body. It is then shown that the inhomogeneous but spherically symmetric dielectric electromagnetic case is reducible to a scalar inverse problem that can be treated by known techniques.