Variable viscosity and activation energy aspects in convection heat transfer over gravity driven solar collector plate for thermal energy storage.

Variable viscosity, activation energy and microgravity effects on Darcy nanofluid for the thermal performance improvement in thermal energy storage systems through stretching flat plate solar collector is the focus of this research. Thermal energy storage (TES) can be improved though solar collectors, phase change materials and photovoltaic cells using nanofluid in the base liquid. To increase the reaction rate in nanoparticles, the activation energy and solar radiations are used for the efficiency of TES.

Is the entropy-weighted water quality index a suitable index for evaluating the groundwater quality in Ha'il, Saudi Arabia?

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.

Statistical quality control based on control charts and process efficiency index by the application of fuzzy approach (case study: Ha'il, Saudi Arabia).

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.

Thermal and flow performance analysis of a concentrated linear Fresnel solar collector with transverse ribs.

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.

Numerical analysis of the energy-storage performance of a PCM-based triplex-tube containment system equipped with arc-shaped fins.

This study numerically intends to evaluate the effects of arc-shaped fins on the melting capability of a triplex-tube confinement system filled with phase-change materials (PCMs). In contrast to situations with no fins, where PCM exhibits relatively poor heat response, in this study, the thermal performance is modified using novel arc-shaped fins with various circular angles and orientations compared with traditional rectangular fins. Several inline and staggered layouts are also assessed to maximize the fin's efficacy.

Deleterious Effect of Air Pollution on Human Microbial Community and Bacterial Flora: A Short Review.

A balanced microbiota composition is requisite for normal physiological functions of the human body. However, several environmental factors such as air pollutants may perturb the human microbiota composition. It is noticeable that currently around 99% of the world's population is breathing polluted air.

The minimality of mean square error in chirp approximation using fractional fourier series and fractional fourier transform.

Chirps are familiar in nature, have a built-in resistance to noise and interference, and are connected to a wide range of highly oscillatory processes. Detecting chirp oscillating patterns by traditional Fourier series is challenging because the chirp frequencies constantly change over time. Estimating such types of functions considering the partial sums of a Fourier series in Fourier analysis does not permit an approximate solution, which entails more Fourier coefficients required for signal reconstruction.

Heat Transport during Colloidal Mixture of Water with AlO-SiO Nanoparticles within Porous Medium: Semi-Analytical Solutions.

In recent years, energy consumption has become an essential aspect in the manufacturing industry, and low heat transfer is one of the obstacles that affect the quality of the final product. This situation can be managed by suspending nanoparticles into ordinary heat transferring fluid (the base fluid). This newly prepared colloidal suspension has better heat transport capabilities.

Peristaltic Phenomenon in an Asymmetric Channel Subject to Inclined Magnetic Force and Porous Space.

This research is engaged to explore biological peristaltic transport under the action of an externally applied magnetic field passing through an asymmetric channel which is saturated with porous media. The set of governing partial differential equations for the present peristaltic flow are solved in the absence of a low Reynolds number and long wavelength assumptions. The governing equations are to be solved completely, so that inertial effects can be studied.

Enhancement of 3D Mass and Heat Transfer within a Porous Ceramic Exchanger by Flow-Induced Vibration.

This work investigates heat transfer enhancement for a porous ceramic heat exchanger. The effect of flow-induced vibration of exchanging air flow through porous tube banks has been tested. A numerical model able to assess the vibration effect on heat and mass transfer inside a porous ceramic exchanger has been carefully developed.

Three-Dimensional Study of Magnetohydrodynamic Natural Convection, Entropy Generation, and Electromagnetic Variables in a Nanofluid Filled Enclosure Equipped with Inclined Fins.

This article provides a numerical study on carbon nanotube-water nanofluid convection in a three-dimensional cavity under a magnetic field effect. Two walls are kept at a hot temperature, and the upper and lower horizontal walls are considered adiabatic. As a new configuration, the beneficial effect of using a nanofluid is coupled with the incorporation of cold V-shape obstacle placed in the cubic cavity; in addition, an external magnetic field is applied toward the horizontal -axis direction.

Improving the Melting Duration of a PV/PCM System Integrated with Different Metal Foam Configurations for Thermal Energy Management.

The melting duration in the photovoltaic/phase-change material (PV/PCM) system is a crucial parameter for thermal energy management such that its improvement can realize better energy management in respect to thermal storage capabilities, thermal conditions, and the lifespan of PV modules. An innovative and efficient technique for improving the melting duration is the inclusion of an exterior metal foam layer in the PV/PCM system. For detailed investigations of utilizing different metal foam configurations in terms of their convective heat transfer coefficients, the present paper proposes a newly developed mathematical model for the PV/PCM-metal foam assembly that can readily be implemented with a wide range of operating conditions.

Control of Magnetohydrodynamic Mixed Convection and Entropy Generation in a Porous Cavity by Using Double Rotating Cylinders and Curved Partition.

In this work, mixed convection and entropy generation analyses in a partitioned porous cavity with double inner rotating cylinders are explored under magnetic field effects. A curved partition shape is considered with identical rotating cylinders and an inclined magnetic field, while the right vertical wall moves with a constant speed in the -direction. Numerical simulations are performed by considering various values of Rayleigh number, Hartman number, Darcy number, inclination of the magnetic field, size of the curved partitions, and rotational speeds of the inner cylinders and their vertical locations with the cavity.

Melting Enhancement in a Triple-Tube Latent Heat Storage System with Sloped Fins.

Due to the potential cost saving and minimal temperature stratification, the energy storage based on phase-change materials (PCMs) can be a reliable approach for decoupling energy demand from immediate supply availability. However, due to their high heat resistance, these materials necessitate the introduction of enhancing additives, such as expanded surfaces and fins, to enable their deployment in more widespread thermal and energy storage applications. This study reports on how circular fins with staggered distribution and variable orientations can be employed for addressing the low thermal response rates in a PCM (Paraffin RT-35) triple-tube heat exchanger consisting of two heat-transfer fluids flow in opposites directions through the inner and the outer tubes.