Center for Space Microelectronics Technology

The 1991 Technical Report of the Jet Propulsion Laboratory Center for Space Microelectronics Technology summarizes the technical accomplishments, publications, presentations, and patents of the Center during the past year. The report lists 193 publications, 211 presentations, and 125 new technology reports and patents

Electro-thermal design and optimization of high-specific-power slotless PM machine for aircraft applications

A 1 MW high-frequency air-core permanent-magnet (PM) motor, with power density over 13 kW/kg (8 hp/lb) and efficiency over 96\%, is proposed for NASA hybrid-electric aircraft application. In order to maximize power density of the proposed motor topology, a large-scale multi-physics optimization, which is not favorable for current electrical machine software, is needed to obtain the best design candidates, which is not favorable for current electrical machine software. Therefore, developing electromagnetic (EM) and thermal analytical methods with computational efficiency and satisfactory accuracy is a key enabling factor for future multi-physics optimization of motor power density. This dissertation summarizes the efforts of developing an electro-thermal analysis and optimization scheme of the proposed motor for aircraft applications. Component hardware tests including windage loss, fan performance, full-scale stator temperature and litz-wire were conducted to validate the proposed prediction methods and provide calibrations in the motor design analysis. Furthermore, slotless litz wire winding geometry and strand size are optimized with the developed electro-thermal modeling including transposition effects. After gaining confidence in the developed electro-thermal models, an optimization design toolbox is built for the hybrid-electric engine systems study. The first application study is in partnership with Rolls Royce's Electrically Variable Engine Project to study thermal management system integration effects on motor sizing. The second study is in collaboration with Raytheon Technologies to study motor transient performance with phase change materials integration, which can be tailored to a hybrid-electric engine mission profile

Center for Space Microelectronics Technology 1988-1989 technical report

The 1988 to 1989 Technical Report of the JPL Center for Space Microelectronics Technology summarizes the technical accomplishments, publications, presentations, and patents of the center. Listed are 321 publications, 282 presentations, and 140 new technology reports and patents

Modeling And Simulation Of All-electric Aircraft Power Generation And Actuation

Modern aircraft, military and commercial, rely extensively on hydraulic systems. However, there is great interest in the avionics community to replace hydraulic systems with electric systems. There are physical challenges to replacing hydraulic actuators with electromechanical actuators (EMAs), especially for flight control surface actuation. These include dynamic heat generation and power management. Simulation is seen as a powerful tool in making the transition to all-electric aircraft by predicting the dynamic heat generated and the power flow in the EMA. Chapter 2 of this dissertation describes the nonlinear, lumped-element, integrated modeling of a permanent magnet (PM) motor used in an EMA. This model is capable of representing transient dynamics of an EMA, mechanically, electrically, and thermally. Inductance is a primary parameter that links the electrical and mechanical domains and, therefore, is of critical importance to the modeling of the whole EMA. In the dynamic mode of operation of an EMA, the inductances are quite nonlinear. Chapter 3 details the careful analysis of the inductances from finite element software and the mathematical modeling of these inductances for use in the overall EMA model. Chapter 4 covers the design and verification of a nonlinear, transient simulation model of a two-step synchronous generator with three-phase rectifiers. Simulation results are show

Numerical Study of the Optical Response of ITO-In2O3 Core-Shell Nanocrystals for Multispectral Electromagnetic Shielding

Nowadays materials to protect equipment from unwanted multispectral electromagnetic waves are needed in a broad range of applications including electronics, medical, military and aerospace. However, the shielding materials currently in use are bulky and work effectively only in a limited frequency range. Therefore, nanostructured materials are under investigation by the relevant scientific community. In this framework, the design of multispectral shielding nanomaterials must be supplemented with proper numerical models that allow dealing with non-linearities and being effective in predicting their absorption spectra. In this study, the electromagnetic response of metal-oxide nanocrystals with multispectral electromagnetic shielding capability has been investigated. A numerical framework was developed to predict energy bands and electron density profiles of a core-shell nanocrystal and to evaluate its optical response at different wavelengths. To this aim, a finite element method software is used to solve a non-linear Poisson's equation. The numerical simulations allowed to model the optical response of ITO-In2O3 core-shell nanocrystals and can be effectively applied to different nanotopologies to support an enhanced design of nanomaterials with multispectral shielding capabilities