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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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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS2014

High Fidelity CFD Analysis and Validation of Rotorcraft Gearbox Aerodynamics Under Operational and Oil-Out Conditions

This document represents the evolving formal documentation of the NPHASE-PSU computer code. Version 3.15 is being delivered along with the software to NASA in 2013.Significant upgrades to the NPHASE-PSU have been made since the first delivery of draft documentation to DARPA and USNRC in 2006. These include a much lighter, faster and memory efficient face based front end, support for arbitrary polyhedra in front end, flow-solver and back-end, a generalized homogeneous multiphase capability, and several two-fluid modelling and algorithmic elements. Specific capability installed for the NASA Gearbox Windage Aerodynamics NRA are included in this version: Hybrid Immersed Overset Boundary Method (HOIBM) [Noack et. al (2009)] Periodic boundary conditions for multiple frames of reference, Fully generalized immersed boundary method, Fully generalized conjugate heat transfer, Droplet deposition, bouncing, splashing models, and, Film transport and breakup.

Gears↗
NASA NTRS2014

Magnetic Gearboxes for Aerospace Applications

Magnetic gearboxes are contactless mechanisms for torque-speed conversion. They present no wear, no friction and no fatigue. They need no lubricant and can be customized for other mechanical properties as stiffness or damping. Additionally, they can protect structures and mechanisms against overloads, limitting the transmitted torque. In this work, spur, planetary and "magdrive" or "harmonic drive" configurations are compared considering their use in aerospace applications. The most recent test data are summarized to provide some useful help for the design engineer.

Perez-Diaz, Jose Luis↗
DOE OSTI2023

Gearbox assembly

A gearbox assembly includes a first gear coupled to a first shaft, a second gear coupled to a second shaft, and a plurality of planet gears that mesh with the first gear and the second gear. The first shaft includes a first shaft stiff portion and a first shaft flexible portion that includes a greater flexibility than a flexibility of the first shaft stiff portion such that the first gear moves in a radial direction. The second shaft includes a second shaft stiff portion and a second shaft flexible portion that includes a greater flexibility than a flexibility of the second shaft stiff portion such that the second gear moves in the radial direction. The first gear and the second gear move to distribute loads substantially equally on the plurality of planet gears.

O'Connor, Ethan Patrick↗
NASA NTRSDate not supplied

Enabling a Weight Efficient Power System for an Electrified Turbofan Through Gearbox Design and Control

Electrified Aircraft Propulsion (EAP) concepts could enable various benefits through a variety of use-cases. Benefits are sought in the form of reduced fuel burn and emissions. Many of these concepts involve the electrification of gas turbine engines. Electrification is accomplished through the integration of electric machines (EMs) with the engine shafts, providing the ability to inject and/or extract power as desired. Energy storage is also a common feature. An often-overlooked feature of the analysis is the means of integrating the EMs with the engine shafts. A trivial solution is to allow each shaft to have its own dedicated EM through independent geartrains. However, non-trivial mechanical integration solutions could provide benefits when considered in coordination with control logic to manage the operation of the propulsion system. Here, such a solution is considered and is shown to have the potential to reduce weight for a relevant conceptual electrified propulsion system. Weight saving benefits are demonstrated for various EAP use-cases. In particular, the mild hybrid application was shown to benefit from a power system weight reduction of 47% and an overall system weight reduction of 29%.

Hybrid Electric Propulsion↗
NASA NTRSDate not supplied

Enabling a Weight Efficient Power System for an Electrified Turbofan Through Gearbox Design and Control

Electrified Aircraft Propulsion (EAP) concepts could enable various benefits through a variety of use-cases. Benefits are sought in the form of reduced fuel burn and emissions. Many of these concepts involve the electrification of gas turbine engines. Electrification is accomplished through the integration of electric machines (EMs) with the engine shafts, providing the ability to inject and/or extract power as desired. Energy storage is also a common feature. An often-overlooked feature of the analysis is the means of integrating the EMs with the engine shafts. A trivial solution is to allow each shaft to have its own dedicated EM through independent geartrains. However, non-trivial mechanical integration solutions could provide benefits when considered in coordination with control logic to manage the operation of the propulsion system. Here, such a solution is considered and is shown to have the potential to reduce weight for a relevant conceptual electrified propulsion system. Weight saving benefits are demonstrated for various EAP use-cases. In particular, the mild hybrid application was shown to benefit from a power system weight reduction of 47% and an overall system weight reduction of 29%.

Hybrid Electric Propulsion↗
DOE OSTI2025

High-Fidelity Modeling of a Type-5 Wind Turbine Gearbox

Type-5 wind turbines are characterized by their use of a hydraulic torque converter and permanent synchronous generator. This combination promotes steady and grid-ready energy without the use of a power converter. Thus, researchers were prompted to study the potential impact on grid reliability, stability, and resilience using a Real Time Digital Simulator (RTDS) model of the type-5 turbine, including a high-fidelity model of its gear box.

13 - HYDRO ENERGY↗
DOE OSTI2016

The Gearbox of the Bacterial Flagellar Motor Switch

Switching of flagellar motor rotation sense dictates bacterial chemotaxis. Multi-subunit FliM-FliG rotor rings couple signal protein binding in FliM with reversal of a distant FliG C-terminal (FliGC) helix involved in stator contacts. Subunit dynamics were examined in conformer ensembles generated by molecular simulations from the X-ray structures. Principal component analysis extracted collective motions. Interfacial loop immobilization by complex formation coupled elastic fluctuations of the FliM middle (FliMM) and FliG middle (FliGM) domains. Coevolved mutations captured interfacial dynamics as well as contacts. FliGM rotation was amplified via two central hinges to the FliGC helix. Intrinsic flexibility, reported by the FliGMC ensembles, reconciled conformers with opposite FliGC helix orientations. FliG domain stacking deformed the inter-domain linker and reduced flexibility; but conformational changes were not triggered by engineered linker deletions that cause a rotation-locked phenotype. These facts suggest that binary rotation states arise from conformational selection by stacking interactions.

59 BASIC BIOLOGICAL SCIENCES↗