Search

In this article, a new energy-efficient reference model has been established for a plastic injection molding plant. However, the proposed model handled difficulties due to the lack of robust and complete data, such as production mix and cooling degree-days. In addition, the proposed model applies three distinct enhanced modeling methodologies, including regression modeling, artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS). Furthermore, these performance parameters were established to assess the accuracy of each model in this work. Moreover, the numerical results show that among the methodologies used in this work, the ANN demonstrated effective performance despite uncertainties in the measured input variables. The ANN numerical results in this paper highlight the ability to accurately assess baseline consumption in the industrial sector, providing a practical tool for decision-makers to improve energy efficiency. [ABSTRACT FROM AUTHOR]

This paper established a novel approach for developing simplified yet accurate models using artificial neural networks (ANNs) in industrial environments. It demonstrates that combining nonlinear regression with neural network modeling enhances predictive accuracy while maintaining the inherent simplicity of ANNs. Industrial sectors are increasingly adopting environmentally friendly practices, driven by the recognition that sustainable initiatives can lead to significant and lasting financial benefits rather than merely a sense of ecological duty. Integrating energy efficiency practices offers potential advantages in waste reduction and resource conservation, which can decrease operating expenses over time. This contributes significantly to pollution mitigation by reducing overall energy consumption cost‐effectively. Numerical simulations based on experimental results validate the proposed method, addressing the complexity and accuracy challenges in business models within the energy sector. [ABSTRACT FROM AUTHOR]

The current work numerically investigates free convection in a square box filled with a non-Newtonian conductive fluid, which is numerically analyzed and is subjected to a steady heat flux at the normal walls, while the horizontal walls are thought of as adiabatic. To examine the impacts of the regulating parameters, including Rayleigh number, behavior index, n, and Hartmann number, on fluid-flow and heat transfer, the governing equations are solved numerically by applying the finite volume method. The results are shown and analyzed in terms of streamlines, isotherms, flow intensity, medium Nusselt, and velocity profiles. [ABSTRACT FROM AUTHOR]

This study extensively examines double-diffusive natural convection of a water nanofluid containing Al2O3 nanoparticles in both horizontal and vertical rectangular enclosures subjected to uniform thermal and solutal fluxes along the horizontal direction. The key contribution of this research is to emphasize the significance of aspect ratio as a critical factor for enhancing heat transfer. Neglecting this factor could have substantial implications for the advancement and practical application of nanotechnology in heat transfer. The study also examines the impact of other relevant parameters namely nanoparticle concentration, thermal Rayleigh number, and three distinct models to calculate effective viscosity and thermal conductivity. A comparison among these models highlights a notable disparity between models based on experimental data (model II and III) and that based on theoretical assumptions (model I). It was revealed that the thermal Rayleigh number manifests a notable impact on both heat and mass transfers, especially for horizontal enclosures, and an augmentation in the aspect ratio improves the convective heat and mass transfers. However, for lower Rayleigh numbers, the aspect ratio effect diminishes. The incorporation of nanoparticles might deteriorate up to 21% or enhance up to 12% heat transfer according to the dominant transfer mode, we obtain the enhancement in conduction and deterioration in convection. Model I gives higher Nusselt and Sherwood numbers, followed by models II and III, but model I showed a peculiar behavior compared to models II and III. A critical aspect ratio is identified which defines the regions where nanofluid enhances heat transfer compared with clear water. [ABSTRACT FROM AUTHOR]

The current study explores numerically mixed convection of thermo-dependent power-law fluids in a square lid-driven enclosure, including the thermal radiation effect. The vertical sidewalls are sustained at both hot and cold temperatures. On the other hand, the cavity is insulated from the horizontal walls. The upper wall is moving along the x-axis. The main governing equations that the Boussinesq approximation is used for are solved using the finite difference method. The simulations focus on the effects of multiple pertinent parameters, including the Richardson number. (Ri = 0.1, 1, 10 and 100), thermal radiation parameter (Rd = 0 and 10), power-law index (0.6 ≤ n ≤ 1.4) and the Pearson number (0 ≤ m ≤ 6). The findings reveal that improving the Richardson number reduces heat transfer. Then, increasing Rd results in a domination of heat conduction for a fluid having a higher thermal conductivity. Also, the growth in the power law-index reduces heat transfer while improving convective flow. Finally, increasing the Pearson number improves the convective flow rate and also the average Nusselt number. [ABSTRACT FROM AUTHOR]

In this paper, numerical study on natural convection heat transfer for confined thermodependent power-law fluids is conducted. The geometry of interest is a fluid-filled square enclosure where a uniform flux heating element embedded on its lower wall is cooled from the vertical walls while the remaining parts of the cavity are insulated, without slipping conditions at all the solid boundaries. The governing partial differential equations written in terms of non-dimensional velocities, pressure and temperature formulation with the corresponding boundary conditions are discretized using a finite volume method in a staggered grid system. Coupled equations of conservation are solved through iterative Semi Implicit Method for Pressure Linked Equation (SIMPLE) algorithm. The effects of pertinent parameters, which are Rayleigh number (103 = Ra = 106), power-law index (0.6 = n = 1.4), Pearson number (0 = m = 20) and length of the heat source (0.2 = W = 0.8) on the cooling performance are investigated. The results indicate that the cooling performance of the enclosure is improved with increasing Pearson and Rayleigh numbers as well as with decreasing power-law index and heat source length. [ABSTRACT FROM AUTHOR]

The present work analyzes both numerically and analytically mixed convection heat transfer in shallow rectangular enclosure files confining ferrofluid, and exposed to temperature conditions of Neuman type with uniform heat flux applied to the short vertical sides, while the top wall is moving with a uniform velocity in the same direction as the applied heat flux. The finite volume method and the SIMPLER algorithm were used to numerically solve the governing equations, while the analytical solution is based on the parallel flow approximation. Simulations are conducted a wide range of controlling parameters, namely, the Reynolds, Hartmann and Richardson numbers and the solid volume fraction of ferroparticles. Effects of mentioned parameters, on the flow structure, temperature fields, and heat transfer rate, were studied and discussed. [ABSTRACT FROM AUTHOR]

The present paper investigates double-diffusive mixed convection inside a horizontal rectangular cavity both numerically using the finite volume method to solve the governing equations and analytically based on the parallel flow approximation developed for the case of shallow enclosures A≫1. Uniform heat and mass fluxes are applied to the short vertical walls, while the horizontal ones are insulated and impermeable, with top wall sliding from left to right. The results show good agreement between both solutions for a wide range of controlling parameters: Peclet number, Pe, Lewis number, Le, the buoyancy ratio, N, and thermal Rayleigh number, RaT. In order to highlight how the convective regimes influence the effect of controlling parameters on flow and heat and mass transfer characteristics, the parameter RaT/Pe3.0 is established to delineate the zones where natural, mixed, and forced convections dominates the heat and mass transfer. Effects of governing parameters on flow intensity and heat and mass transfer rates are illustrated and discussed in terms of the stream function, Ψ, the average Nusselt number, ̅𝑁̅̅𝑢̅, the average Sherwood number 𝑆̅̅ℎ̅, for the three separated convective regimes. [ABSTRACT FROM AUTHOR]

Two-dimensional steady laminar natural convection of a viscoelastic fluid represented by generalized second-grade fluid model in a square enclosure is studied. The cavity is submitted at its vertical sides to a uniform density of heat flux while the horizontal walls are insulated, without slipping conditions at all the solid boundaries. The governing conservation and constitutive equations with the corresponding boundary conditions are solved by finite volume method in a collocated grid system. The contributions of shear rate dependent and elastic characteristics of the viscoelastic fluid are investigated on momentum and heat transport. The effects of elastic number (E) in the range 0 - 1 on heat transfer and fluid motion are interpreted for a power-law index (n) in the range 1.4 - 0.6 and nominal values of Rayleigh number (Ra) range of 10³ to 105. [ABSTRACT FROM AUTHOR]

Copyright of Nature & Technology / Nature & Technologie is the property of Nature et Technologie Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Two-dimensional steady-state Rayleigh-Bénard convection of thermodependent power-law fluids confined in a square cavity, heated from the bottom and cooled on the top with uniform heat fluxes, has been conducted numerically using a finite difference technique. The effects of the governing parameters, which are the Pearson number (0 = m = 10), the flow behaviour index (0.6 = n = 1.4), and the Rayleigh number (0 < Ra = 105), on the flow onset, flow structure, and heat transfer have been examined. The heatlines concept has been used to explain the heat transfer deterioration due to temperature-dependent viscosity effect that m expresses. [ABSTRACT FROM AUTHOR]