Browsing by Author "Pirmoradian, M."

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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
Free vibration analysis of a functionally graded porous nanoplate in a hygrothermal environment resting on an elastic foundation
(Elsevier B.V., 2024) Salahshour, Soheıl; Mokhtarian, A.; Hashemian, M.; Pirmoradian, M.; Salahshour, S.
This research investigates the free vibrational behavior of a functionally graded porous (FGP) nanoplate resting on an elastic Pasternak foundation in a hygrothermal environment. The nanoplate is modeled based on the nonlocal strain gradient theory (NSGT) and considering several plate theories including the CPT (classical plate theory), the FSDT (first-order shear deformation theory), and the TSDT (third-order shear deformation theory). Several patterns are investigated for the dispersion of pores, and the surface effects are incorporated to enhance the precision of the model. The governing equations and boundary conditions are derived via Hamilton's principle and an exact solution is provided via the Navier method. The impacts of several parameters on the natural frequencies are inspected such as length scale and nonlocal parameters, surface effects, porosity parameter, hygrothermal environment, and coefficients of the foundation. The results show that the impact of the porosity parameter on the natural frequencies of nanoplates is significantly dependent on the porosity distribution pattern. It is discovered that by increasing the porosity parameter from 0 to 0.6, the relative changes of natural frequencies vary from a decrease of 30 % to an increase of 6 %. © 2024 The Author(s)
Citation Count: 0
Numerical Simulation of Combined Convective Heat Transfer in a Sinusoidal Cavity With Lid-Driven Cap Affected by Fractal Blocks
(Elsevier B.V., 2025) Abdolvand, R.; Yoosefzadeh, S.; Jaffar, H.A.; Abdul-Redha, H.K.; Akbari, O.A.; Ahmadi, G.; Pirmoradian, M.
Improving the thermal performance of equipment on large and small scales is one of the most important issues in engineering. In this numerical study, the flow and combined convection heat transfer in a two-dimensional (2D) sinusoidal cavity affected by the movement of indirect hot fluid flow are investigated using the finite volume method. By using water/silver nanofluid in volume fractions (φ) of 0 to 0.06 and using fractal surfaces in a 2D cavity with a lid-driven cap in Richardson numbers (Ri) 0 to10, an attempt is made to increase the heat transfer efficiency of the sinusoidal hot surface. The results of this research show that due to the increase in the convective heat transfer coefficient resulted from the strengthening of the fluid velocity, a significant decrease in the temperature of the hot surface is achieved. At Ri = 10, due to the slower movement of the cap and the full compliance of the fluid with the sinusoidal surface, the heat penetration in the fluid layers increases and the temperature graphs become more uniform. The flow circulation between the two hot and cold sources is affected by the density gradients in the cooling fluid and the movement of the cap can create a different temperature distribution. The fluid temperature distribution is also dependent on moving areas in the cavity. The placement of fluid on fractal surfaces is associated with extreme velocity changes. Due to the presence of viscosity and the formation of the velocity boundary layer, this behavior also affects the movement of the fluid layers to the solid surface areas. The highest value of the Nusselt number (Nu) is gained during fluid contact with a cold lid-driven cap on the left side of the cavity. As the fluid moves further on the surfaces of the moving cavity, the hot fluid gradually exchanges its energy with the cavity cover and the fluid cools down. The presence of solid nanoparticles in a higher φ has a significant effect on reducing the temperature of the hot surface, which is due to the increase in the thermal conductivity of the cooling fluid. Compared to the base fluid, this behavior at φ = 0.06 has created a higher thermal efficiency increase of about 15 %. The lowest shear stress is related to the areas of fluid separation on the curved surface. In all investigated cases, the increase of φ can increase the average shear stress between 35 % and 43 % in different Ri. © 2024
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