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Ngachin M.,Waste Control Specialists LLC | Galdamez R.G.,Crane Aerospace and Electronics | Gokaltun S.,Florida International University | Sukop M.C.,Florida International University
International Journal of Modern Physics C | Year: 2015

This study describes the behavior of bubbles rising under gravity using the Shan and Chen-type multicomponent multiphase lattice Boltzmann method (LBM) [X. Shan and H. Chen, Phys. Rev. E47, 1815 (1993)]. Two-dimensional (2D) single bubble motions were simulated, considering the buoyancy effect for which the topology of the bubble was characterized by the nondimensional Eötvös (Eo), and Morton (M) numbers. In this study, a new approach based on the "effective buoyancy" was adopted and proven to be consistent with the expected bubble shape deformation. This approach expands the range of effective density differences between the bubble and the liquid that can be simulated. Based on the balance of forces acting on the bubble, it can deform from spherical to ellipsoidal shape with skirts appearing at high Eo number. A benchmark computational case for qualitative and quantitative validation was performed using COMSOL Multiphysics based on the level set method. Simulations were conducted for 1 ≤ Eo ≤ 100 and 3 × 10-6 ≤ M ≤ 2.73 × 10-3. Interfacial tension was checked through simulations without gravity, where Laplace's law was satisfied. Finally, quantitative analyses based on the terminal rise velocity and the degree of circularity was performed for various Eo and M values. Our results were compared with both the theoretical shape regimes given in literature and available simulation results. © 2015 World Scientific Publishing Company.

Altshuller D.A.,Crane Aerospace and Electronics
Proceedings of the 2010 American Control Conference, ACC 2010 | Year: 2010

The paper considers the problem of robust stability for a class of linear time-periodic systems with a matrix having a stable constant part. The main result is given in terms of the frequency response of the constant part and is then used to derive simple stability criteria for some special cases, including the Hill's and Mathieu's equations. © 2010 AACC.

Wang F.F.,Crane Aerospace and Electronics
ASME 2013 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems, InterPACK 2013 | Year: 2013

Cadmium plated circular connectors and chromate conversion coated aluminum chassis are widely used on electronic equipment for both civilian and military aerospace applications. This article discusses electrical bonding resistance problems associated with cadmium plated circular connectors and chromate conversion coated aluminum chassis and proposes an innovative way to solve that problem. Copyright © 2013 by ASME.

Parker E.,Crane Aerospace and Electronics | Narveson B.,Narveson Innovative Consulting | Alderman A.,Anagenesis Inc. | Burgyan L.,LTEC Corporation
IEEE International Workshop on Integrated Power Packaging, IWIPP 2015 | Year: 2015

The Packaging Committee of the Power Sources Manufacturers Association (PSMA) organized and sponsored a special project to study how innovations in 3D packaging either were currently or are projected to be leveraged by the power electronics industry. Phase 1 of this special project resulted in a Technology Report titled '3D Power Packaging' [1] that was prepared under contract by Tyndall Institute of Cork, Ireland and published March 2014. Phase 2 of the special project continued to examine 3D power packaging but with a focus on embedded substrate technologies; it was prepared under contract LTEC Corporation with subcontract to Anagenesis, Inc. and Fraunhofer-Institure and was published March 2015 [2]. The phase 2 report covers a spectrum from active and passive component technologies for embedding, die attach materials and processes, thermal management, and additive manufacturing; however the heart of the report is a chapter on technologies for embedding in PCBs and inorganic substrates. This paper provides an overview of the findings from that report regarding technologies that are currently in production and those forecast to be viable for volume production in the near future. © 2015 IEEE.

Spencer K.,Crane Aerospace and Electronics
Microwave Journal | Year: 2011

The Multi-Mix micro-multi-function module technology described in this article is being used for highly integrated assemblies. These include frequency converters, T/R modules, beamformers, radiating elements and advanced switch matrices. The belief is that the use of this technology will allow designers greater flexibility and the ability to add further levels of integration in the same footprint currently being utilized. The platform also provides for low loss, highly reliable structures without the sacrifice of cost and size.

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