Polarimetric SAR Interferometryによる森林の特徴について

Surface modifications to enhance dropwise condensation

Enhanced cooling, coupled with novel designs and packaging of semiconductors, has revolutionized communications, computing, lighting, and electric power conversion. It is time for a similar revolution that will unleash the potential of electrified propulsion technologies to drive improvements in fuel-to-propulsion efficiency, emission reduction, and increased power and torque densities for aviation and beyond. High efficiency and high specific power (kW/kg) electric motors are a key enabler for future electrification of aviation. To improve cooling of emerging synchronous machines, and to realize performance and cost metrics of next-generation electric motors, electromagnetic and thermomechanical co-design can be enabled by innovative design topologies, materials, and manufacturing techniques. This paper focuses on the most recent progress in thermal management of electric motors with particular focus on electric motors of significance to aviation propulsion.

https://www.mdpi.com/1996-1073/12/19/3594/pdf

Thermal Management of High-Power Density Electric Motors for Electrification of Aviation and Beyond

Review article: Microscale evaporative cooling technologies for high heat flux microelectronics devices: Background and recent advances

/pdf/combined-dielectrophoretic-and-electrohydrodynamic-c4jr3x5pr7.pdf

Combined Dielectrophoretic and Electrohydrodynamic Conduction Pumping for Enhancement of Liquid Film Flow Boiling

Research on heat transport in microscale has been generating much interest in the recent years due to the development of state-of-the-art high-powered electronics used in aerospace and terrestrial applications and the large amount of heat produced during their operation. Microscale two-phase-flow heat-transport devices are seen as one solution to this problem of high heat-flux removal. Microscale devices have extremely high heat fluxes due to the small heat-transfer surface area. In addition, the need for robust, nonmechanical, lightweight, low-noise, and low-vibration devices in specialized aerospace applications has led researchers to investigate electrically driven flow devices rather than their mechanical counterparts. This paper, for the first time, presents the results of an experimental study of a unique microscale heat-transport device that is driven by electrohydrodynamic (EHD) conduction pumping. Results from ground-based single-phase experiments with a microscale EHD pump are compared with experiments conducted on board a variable-gravity parabolic flight. Data show that the EHD pump functions well in both environments and can be potentially used in heat-transport devices in the absence of gravity. This is the first step in broader-scale future experimental work that will involve heat transfer, including phase change.

http://www.electrostatics.org/images/ESA2012_H3.pdf

Terrestrial and Microgravity Experimental Study of Microscale Heat-Transport Device Driven by Electrohydrodynamic Conduction Pumping

Condensation proceeds as dropwise or filmwise depending on the wettability of the condensing surface. These two modes of condensation have disparate heat transfer coefficients, with dropwise often ...

Switchable Wettability for Condensation Heat Transfer.

Gen3, Embedded Cooling, promises to revolutionize thermal management of advanced microelectronic systems by eliminating the sequential conductive and interfacial thermal resistances which dominate the present “remote cooling” paradigm. Single-phase interchip microfluidic flow with high thermal conductivity chips and substrates has been used successfully to cool single transistors dissipating more than 40kW/cm2, but efficient heat removal from transistor arrays, larger chips, and chip stacks operating at these prodigious heat fluxes would require the use of high vapor fraction (quality), two-phase cooling in intra- and inter-chip microgap channels. The motivation, as well as the challenges and opportunities associated with evaporative embedded cooling in realistic form factors, is the focus of this paper. The paper will begin with a brief review of the history of thermal packaging, reflecting the 70-year “inward migration” of cooling technology from the computer-room, to the rack, and then to the single chip and multichip module with — and liquid-cooled coldplates. Discussion of the limitations of this approach and recent results from single-phase embedded cooling will follow. This will set the stage for discussion of the development challenges associated with application of this Gen3 thermal management paradigm to commercial semiconductor hardware, including dealing with the effects of channel length, orientation, and manifold-driven centrifugal acceleration on the governing behavior.

/pdf/challenges-and-opportunities-in-gen3-embedded-cooling-with-28rzdkfspu.pdf

Challenges and opportunities in Gen3 embedded cooling with high-quality microgap flow

Liquid film flow boiling is used in many terrestrial thermal management applications as a heat transport mechanism. However, it suffers in microgravity applications such as spacecraft thermal management because the gravitational body force is not present to facilitate liquid film flow and bubble removal from the heater surface. One way of overcoming these constraints is to use an electrical field to move a liquid film in the absence as well as in the presence of gravity. In this experimental study, electrohydrodynamic conduction pumping is used to rewet the heater surface during liquid film flow boiling. The experiments are performed both terrestrially and onboard a variable-gravity parabolic flight. Terrestrial steady-state results show a maximum superheat reduction of 6°C and a 62% increase in critical heat flux when the electrohydrodynamic pump is moderately activated. The parabolic flight transient results indicate that, although there was an adverse effect of electrohydrodynamic on heater surface tem...

Effect of Gravity on Electrohydrodynamic Conduction Driven Liquid Film Flow Boiling

In its Carbon Cycle research efforts, prioritized by the National Science Foundation Decadal Survey and mandated by the US Congress, NASA is developing an airborne P-band Ecological Synthetic Aperture Radar called EcoSAR By using polarimetric and interferometric techniques, and a digital beamforming phased-array architecture, EcoSAR will characterize biomass and ecological structure in three dimensions aboard a P-3 aircraft One of the main components in the EcoSAR instrument development is the 32 channel RF Electronics Unit (REU) The multi-channel solid-state REU design provides amplification, conditioning, blanking, and several calibration schemes to meet EcoSAR's science and engineering requirements The design, assembly, and testing of the REU is well underway with 16 of 32 channels completed The remaining channels are nearly finished The REU once complete, will be calibrated and integrated with the rest of the system in preparation for EcoSAR's first flight campaign

Franklin Robinson

Papers

Terrestrial and Microgravity Experimental Study of Microscale Heat-Transport Device Driven by Electrohydrodynamic Conduction Pumping

Switchable Wettability for Condensation Heat Transfer.

Challenges and opportunities in Gen3 embedded cooling with high-quality microgap flow

Effect of Gravity on Electrohydrodynamic Conduction Driven Liquid Film Flow Boiling

Development of the RF electronics unit for NASA's ecological synthetic aperture radar