Optimal Energy Systems (OES) is currently designing and manufacturing flywheel based energy storage systems that are being used to provide pulses of energy for charging high voltage capacitors in a mobile military system. These systems receive their energy from low voltage vehicle bus power ( 480 VDC) and provide output power at over 10 000 VDC without the need for dc-dc voltage conversion electronics. This energy conversion is accomplished through the use of OES patented ultra high-speed flywheel power module (FPoM) technology. In this paper, adaptation of the OES FPoM technology to energy storage for electromagnetic aircraft launch system (EMALS) applications is described. Physical system design parameters are summarized for the FPoM. Transient PSPICE electrical and MSC/Nastran FEA thermal analyses characterize operation and response in a conceptual EMALS energy storage environment.

The geometry of the characteristic element forming the artificial structure of an electromagnetic metamaterial defines the way the metamaterial will interact with electromagnetic waves, and accordingly, how it will transmit, reflect, and absorb electromagnetic energy. Metamaterials have been discovered that can manipulate electromagnetic waves to create perfect absorption of incident electromagnetic energy using relatively simple elemental geometries. But the phenomenon is confined to very narrow frequency bandwidths owing to the mono-resonance characteristics of simple cellular structures. Complex cellular geometries based on the combination of many different fundamental building blocks may be able to constructively couple many more resonances and broaden the perfect absorption bandwidth. We describe here a metasurface based upon geometric inversion of a set of conformal mapping contours. The resulting geometry forms a nearly continuous series of perfect absorption resonances within an ultrathin (λ/165) metasurface to develop broadband absorption in a frequency range of interest for downhole chemical spectroscopy. The metasurface is derived from a geometric inversion of the Rhodonea, or more commonly called four-leaf roses, conformal mapping contours and was found to exhibit a near zero index metamaterial (NZIM) behavior. An uncooled microbolometer design is described that uses the metasurface geometry on a single VO2 thermometric substrate leading to an infrared detector with predicted maximum absorption of 99.94% at 4.3 μm and an absorption bandwidth of 170% FWHM on 15.8 μm center wavelength, coincident with important chemical spectra of downhole hydrocarbons. The infrared detector design has a predicted maximum detectivity D* = 1.5 × 109 cm$$\sqrt{\text{Hz}}$$Hz/W and noise equivalent difference temperature NEDT of 70 mK at a frame rate of 60 Hz. These levels of detector performance conventionally would be achievable only with cryogenically cooled technologies and could represent a significant step in the effort towards deploying an in situ infrared chemical spectroscopy sensor into downhole logging applications.

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In Part I of this paper, a combination of Airy stress functions and direct displacement functions was utilized to obtain the plane elasticity solution for the stresses and displacements in a multilayer laminated orthotropic strip subjected to a temperature gradient that is arbitrarily symmetric in the longitudinal direction. The solution is exact for the specific boundary conditions associated with satisfaction of zero slope of transverse displacement at the strip ends and shear traction free edges at the strip ends. In Part II of this paper, numerical results are presented for several examples and compared to detailed finite element analyses for approximate zero edge slope and free edge boundary conditions. The results indicate the shear and peel stress concentrations and axial stress distributions for the boundary condition are in excellent agreement with the finite element analysis results for the zero edge slope case and correlate with the free edge boundary condition over a broad range of temperature gradient cases. This correlation with the free edge numerical analysis indicates the theoretical approach is feasible as a conceptual design tool for a reasonable range of free edge engineering problems.