pb noties - related:
>>19914276 US Navy, "I've got your six" @ 8 a.m.
QClock November 14, 2023 - I've Got Your Six - Locked & Loaded
https://twitter.com/TheInsiderPaper/status/1724384676155171272
NEW - A prominent Mexican magistrate who was the country’s first citizen to be granted a non-binary passport was found dead on Monday, authorities said.
6:11 AM · Nov 14, 2023
·16.4K Views
https://www.nextbigfuture.com/2023/11/breakthrough-thermoacoustic-stirling-generator-converts-to-energy-with-no-moving-parts.html
Breakthrough Thermoacoustic Stirling Generator Converts to Energy With No Moving Parts
November 12, 2023 by Brian Wang
China has built the most powerful thermoacoustic Stirling generator. The prototype delivered a groundbreaking 102 kilowatts of power from a heat source of 530 degrees Celsius (986 Fahrenheit). This is the first time this type of breakthrough generator has gone over 100 kilowatts. Thermoacoustic engine achieves high thermal-to-electrical efficiencies with no moving parts. The new generator converts sound directly into electrical energy.
The Chinese design can be used for ultraquiet submarines.
Nasa’s LEW-TOPS-80 patent proposed a thermoacoustic engine paired with an alternator to generate electricity in space. NASA has not shown a prototype.
NASA Glenn’s thermoacoustic power converter reshapes the conventional Stirling engine from a toroidal shape into a straight colinear arrangement. Instead of relying on failure-prone mechanical inertance and compliance tubes, this design achieves acoustical resonance by using electronic components. In a typical Stirling engine, the acoustical wave travels around a toroid and reflects back, forming a standing wave. In Glenn’s device, by contrast, the wave instead travels in a straight plane where a transducer receives the acoustical wave and electrical components modulate the signal. A second transducer on the diametrically opposed side reintroduces the acoustic wave with the correct phasing to achieve amplification and resonance. Glenn’s design allows the transducers to operate at high frequency while presenting a mass rather than stiffness impedance. Glenn’s magnetostrictive alternator uses stacked magnetostrictive materials under a biased magnetic and stress-induced compression. The acoustic energy from the engine travels through an impedance-matching layer (which can be formed from aerogel materials) that is physically connected to the magnetostrictive mass. Compression bolts keep the structure under compressive strain, allowing for the micron-scale compression of the magnetostrictive material and eliminating the need for bearings. The alternating compression and expansion of the magnetostrictive material creates an alternating magnetic field that then induces an electric current in a coil wound around the stack. This alternator produces electrical power from the acoustic pressure wave and, when the resonant frequency is tuned to match the engine, can replace the linear alternator to great effect.
Benefits
Efficient: Offers very high thermal-to-electrical efficiency compared to other heat engines
Reliable: Features no moving parts or bearing systems, limiting opportunities for failure
Lower-cost: Reduces fabrication expense by using fewer parts and allowing wide tolerances in manufacturing
Compact: Enables significantly reduced engine mass and volume
Versatile: Provides flexibility in design so that any heat source can be used to provide power