Browsing by Author "Omar, I."

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Citation Count: 0
Applying different machine learning algorithms to predict the viscosity behavior of MWCNT–alumina/water–ethylene glycol (80:20) hybrid antifreeze
(Elsevier B.V., 2024) Salahshour, Soheıl; Omar, I.; Saddam, A.B.; Baghoolizadeh, M.; Salahshour, S.; Pirmoradian, M.
While machine learning has become the new way of analyzing data, neutral networks form the basis of this revolutionary technology. In this work, we shall employ the power of neural networks to analyze and demystify the processes in nanofluids. By combining the precision of neural networks with the optimization capabilities of genetic algorithms, we aim to create a more accurate and efficient prediction model for MWCNT-alumina/water-ethylene glycol (80:20) hybrid antifreeze. Our approach entails using an MLP neural network and several training functions (LM, GD, BFGS, BN) with an adjustable number of neurons. The inputs of the network are φ (solid volume fraction or ϕ), temperature (T), and shear rate (γ), and the output is μnf of MWCNT-alumina/water-ethylene glycol (80:20) hybrid anti-freeze. To improve the accuracy of the final model, we use genetic optimization to make final adjustments to the parameters of the neural network. Utilizing the detailed analysis of the primary characteristics of these algorithms, we conclude that the BFGS function is the best to obtain neural network training. Steady performance achieved by this function—0.99828 of the R-value and RMSE value significantly equal to 0.213—illustrates good stability and accuracy of the suggested model. This work contributes to progressing the existing knowledge about the behavior of nanofluids and can stimulate further improvement in heat transfer and energy utilization. © 2024 The Author(s)
Citation Count: 0
Static Stability of Functionally Graded Porous Nanoplates Under Uniform and Non-Uniform In-Plane Loads and Various Boundary Conditions Based on the Nonlocal Strain Gradient Theory
(Elsevier B.V., 2025) Salahshour, Soheıl; Marhoon, T.; Babadoust, S.; Najm, A.S.; Pirmoradian, M.; Salahshour, S.; Sajadi, S.M.
This work examines the buckling behavior of functionally graded porous nanoplates embedded in elastic media. Size effects are added to the nanoplate constitutive equations using nonlocal strain gradient theory. The four-variable refined plate theory is employed for nanoplate modeling. This theory assures stress-free conditions on both sides of the nanoplate and has less uncertainty than high-order shear deformation theories. It is postulated that the nanoplate experiences in-plane compressive loads, which may have both linear and nonlinear distributions. Additionally, uniform and non-uniform porosity distributions are considered. The governing partial differential equations are extracted using the notion of the minimal total potential energy. Following this, the Galerkin method is employed to solve these equations utilizing trigonometric shape functions. Simple, clamped, and combined boundary conditions for nanoplate edges are studied. Once the governing algebraic equations were extracted, the critical buckling load of the nanoplate is determined. To conduct a validation study, the obtained data are juxtaposed with the findings of previous studies, revealing a notable level of concurrence. After the critical buckling load has been ascertained, an inquiry is undertaken to assess the influence of various parameters including nonlocal and length scale parameters, boundary conditions, porosity distribution type, in-plane loading type, geometric dimensions of the nanoplate, and stiffness of the elastic environment, on the static stability of nanoplates. © 2024
Citation Count: 0
The Thermal-Flow Performance of Water-Al2o3 Nanofluid Flow in an Elliptical Duct Heat Exchanger Equipped With Two Rotating Twisted Tapes
(Elsevier Ltd, 2025) Salahshour, Soheıl; Omar, I.; Ghanim, W.K.; Fares, M.N.; Fazilati, M.A.; Salahshour, S.; Esmaeili, S.
Background: The thermal-flow performance of nanofluid (NF) flow in an elliptical duct heat exchanger fitted and turbulated with two rotating tapes is investigated. The issues concerning rotating twisted tapes inside the oval tubes using NF as the working fluid simulated with two-phase modeling have received less attention in previous studies. Methods: Considering the importance of employing the heat transfer improving methods in tubular heat exchangers, the passive and ative heat transfer improving methods examined here. As a novel study case, the rotated tapes beside the water-Al2O3 NF of was used; and sensitivity analysis was performed to reveal the effect of the volume fraction of nanoparticles (ϕ), tapes rotational speed and Re number on the Nu number, pumping power and figure of merit (FOM). The heat flux of 5000 Wm−2 was applied to the wall surface, and the two-phase mixture method was employed for the simulation. The heat exchanger performance is studied in cases of fixed and rotating twisted tapes with three different rotational speeds. The results show that increasing the Re number, ϕ and the rotation speed of the blades would increase the Nu number and pumping power in all cases. The increase in ϕ improves the Nu number by 6.1 %–19.4 % and the pumping power by 59.2–280 %. The Nu number change by increasing ϕ is lower at low Re numbers and becomes higher at high Re numbers. The effect of ϕ increment on heat transfer is increasing but took place with a higher inclination rate in rotating tapes rather than stationary tapes and plain tube cases. In the cases of rotated twisted tape mode, the value of FOM is always greater than one and is below 0.9 for stationary mode. Significant findings: The highest value of FOM is 1.57, which is for the highest rotational speeds, the lowest Re number, and ϕ = 1 %. Increasing the Re number reduces the FOM while increasing ϕ improves it. Practical significance and potential area of application: The increasing need for efficient heat transfer in heat exchanger devices necessitated the application of heat transfer augmentation techniques. The effects of twisted tapes, their rotation, and the application of NFs in heat exchangers as the active and passive heat transfer increment methods are studied numerically. © 2025 The Author(s)