Aeronautical engineering: A continuing bibliography with indexes (supplement 301)

This bibliography lists 1291 reports, articles, and other documents introduced into the NASA scientific and technical information system in Feb. 1994. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment, and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics

Binder-free K2CO3 granules for thermochemical heat storage

Thermochemical heat storage systems encounter challenges such as agglomeration within the reactor bed,which limits gas molecule movement and diminishes overall efficiency. This study proposes an approachto mitigate this issue by producing millimeter-sized potassium carbonate (K2CO3) granules withoutbinders using the wet granulation technique. Through 10 cycles, initial hydration loading started at 0.19molH2O/molK2CO3 in the first cycle and increased steadily to 1.42 molH2O/molK2CO3 by the 10th cycle.During 6-hour hydration periods, the released heat from the granules significantly increased from 57 J/gto 535 J/g after 10 cycles, attributed to changes in pore volume and granule structure throughout cycling.Despite pore enlargement, the granules maintained structural integrity, highlighting their stability acrossrepeated cycles. This study underscores the potential of binder-free potassium carbonate granules toenhance heat storage efficiency, providing valuable insights for optimizing thermochemical heat storagesystems, particularly in terms of scalability for mass production of these granules

Membrane-encapsulated salt hydrate:An anti-agglomeration approach to enhance cyclability

Heat has a crucial effect on the general energy consumption in the world. Hence, the need for an environmentallyfriendly and energy-efficient substitute is on the rise as far as reducing carbon footprints is concerned, wherethermochemical materials (TCM) can be a viable option. Potassium carbonate (K2CO3) has shown the most promisingcharacteristics for seasonal heat storage due to its high energy density, cost-effectiveness, and reaction safety.However, due to the accruing of salt crystal clumping after a few hydration/dehydration cycles, the operational lifecycle of K2CO3 is challenged with diminished energy density and kinetics of hydration. In the present study, tomitigate this challenge, a new encapsulation strategy based on membrane science is used to address bothagglomeration mitigation and preservation of crystal integrity without limiting the water vapour diffusion inside thecrystal by employing a separative polymeric layer. This research introduced the encapsulation process along withsuitable crystal morphology with a focus on optimal pore structure and hydration kinetics as a mechanism foroptimizing the efficiency of transport of water vapour. The key results of this research provide a cheap and easy-to-implementmethod to prevent agglomeration while preserving the cyclic performance characteristics of salt hydratesfor heat battery application

Characterizing Na2S kinetics for thermochemical energy storage applications through algorithmic optimization

In this study, the application of the Shuffled Complex Evolution (SCE) method for algorithmic optimization has demonstrated its effectiveness in calibrating the reaction model for sodium sulfide (Na2S) for use in thermochemical energy storage (TCES) systems. The research revealed that both twostep and three-step reaction models for Na2S align well with experimental data. This method significantly streamlines the data requirements, as it relies primarily on time-series data of conversion, temperature, and pressure, which are readily accessible from Thermogravimetric (TG) measurements. However, despite these advancements, thorough validation of these models is essential, especially under diverse operating conditions beyond the initial test environments. This study highlights the potential of advanced algorithmic techniques for material characterization for TCES applications