Publications by authors named "N Abdessayed Khedher"

Article Synopsis
  • This research explores how variable viscosity, activation energy, and microgravity affect the performance of Darcy nanofluid in improving thermal energy storage (TES) via solar collectors.
  • The study emphasizes that using nanofluid can enhance heat and mass transfer in TES applications, which include heat exchangers and solar power systems, especially when combined with solar radiation and phase change materials.
  • A mathematical model is developed to simulate oscillating heat transfer in TES, revealing that lower viscosity increases fluid velocity while higher activation energy and microgravity lead to better thermal and mass transfer efficiencies.
View Article and Find Full Text PDF

This study examined the groundwater quality in Ha'il according to World Health Organization (WHO) standards using the entropy-weighted water quality index (EWQI) more accurately. The study investigated several parameters in groundwater quality and found that more than 75% of the changes in Ha'il can be attributed to four main factors (MF1, MF2, MF3, and MF4). The MF1 was found to have the biggest role in controlling more than 33% of the changes in the water quality.

View Article and Find Full Text PDF

Fuzzy methods using linguistic expressions and fuzzy numbers can provide a more accurate examination of manufacturing systems where data is not clear. Researchers expanded fuzzy control charts (CCs) using fuzzy linguistic statements and investigated the current process efficiency index to evaluate the performance, precision, and accuracy of the production process in a fuzzy state. Compared to nonfuzzy data mode, fuzzy linguistic statements provided decision makers with more options and a more accurate assessment of the quality of products.

View Article and Find Full Text PDF

This article deals with the impact of including transverse ribs within the absorber tube of the concentrated linear Fresnel collector (CLFRC) system with a secondary compound parabolic collector (CPC) on thermal and flow performance coefficients. The enhancement rates of heat transfer due to varying governing parameters were compared and analyzed parametrically at Reynolds numbers in the range 5,000-13,000, employing water as the heat transfer fluid. Simulations were performed to solve the governing equations using the finite volume method (FVM) under various boundary conditions.

View Article and Find Full Text PDF