Numerical Analysis Research Articles

Comparative analysis on the forced and mixed convection in a hybrid nanofluid flow over a stretching surface: a numerical analysis

Comparative analysis on the forced and mixed convection in a hybrid nanofluid flow over a stretching surface: a numerical analysis

Numerical analysis of a protective coating for mining industry feed chute

Numerical analysis of a protective coating for mining industry feed chute

Numerical analysis and industrial practice of single-flow post-combustion oxygen lance with high oxygen supply intensity

Numerical analysis and industrial practice of single-flow post-combustion oxygen lance with high oxygen supply intensity

Research on multilateral collaboration strategies in agricultural seed quality assurance.

Seeds, as the initial products in agricultural systems, play a pivotal role in ensuring quality, fundamental to national food security and sustainable agricultural development. This study introduces a concept integrating public governance and evolutionary game theory to construct a quadripartite evolutionary game model involving seed companies, certification agencies, farmers, and governmental departments. It considers the strategic choices of these stakeholders under varying economic motivations and market mechanisms, as well as the influence of external regulation and incentives on game strategies. The existence conditions for evolutionarily stable strategy combinations are determined using the Lyapunov first method, and MATLAB is employed for numerical simulation analysis to validate the game analysis under initial conditions. The simulation results reveal two potential equilibrium points corresponding to different strategic choices among stakeholders. The study finds that producing high-quality seeds and the refusal of certification agencies to engage in rent-seeking are crucial for ensuring seed quality. Additionally, the cost-benefit ratio of seed companies, the speculative cost of certification agencies, and the rights-protection cost of farmers are key determinants in the evolution of seed quality assurance strategies. This research also holds practical significance in enhancing seed quality assurance mechanisms and fostering sustainable development in agriculture.

Comparative Numerical Energy and Performance Analysis of Solar Photovoltaic and Solar Thermal Power Generation

Comparative Numerical Energy and Performance Analysis of Solar Photovoltaic and Solar Thermal Power Generation

Numerical analysis of optimal control problems governed by fourth‐order linear elliptic equations using the Hessian discretization method

Numerical analysis of optimal control problems governed by fourth‐order linear elliptic equations using the Hessian discretization method

Numerical Analysis of the Plateau Problem by the Method of Fundamental Solutions

Numerical Analysis of the Plateau Problem by the Method of Fundamental Solutions

Numerical analysis of electrothermoconvection of a dielectric nanofluid in a heated cavity

A numerical analysis of electrohydrodynamic (EHD) flow and heat transfer of nanofluid in a heated rectangular cavity is presented. A two-dimensional (2D) rectangular cavity heated from the bottom is considered. An electric potential difference is applied vertically, with the bottom wall acting as a high-voltage electrode, and the top wall is grounded. TiO2-25 # transformer oil nanofluid with nanoparticle volume fraction ranging from 0–5% is considered. The numerical model for EHD flow and heat transfer of nanofluid is implemented in the finite-volume method (FVM) based numerical framework of OpenFOAM. A single-phase approach based on the effective properties is adopted to model the nanofluids. A two-way coupled EHD flow model is employed to consider mutual interactions of flow and electric field variables. The flow and heat transfer behavior of nanofluids in the presence of an electric field is quantified with reference to the key parameters, electric Rayleigh number (T), and the nanoparticle volume fraction ϕ. The addition of nanoparticles increased the viscosity and marginally reduced the natural convective flow and heat transfer. However, EHD flow induced by the electric field aided in overcoming the weak natural convection flow in nanofluids. Results confirm that nanofluids’ net effective heat transfer rates are notably increased in the presence of the electric field. For the parameters under consideration, combining electric fields with nanofluids led to a significant heat transfer enhancement of up to 32.3%. The present study showcases the feasibility of combining passive heat transfer enhancement using nanoparticles and active heat transfer enhancement using EHD flow.

Numerical Analysis of Airflow in Trachea Affected by Thyroid Cancer Using Finite Volume Method

Numerical Analysis of Airflow in Trachea Affected by Thyroid Cancer Using Finite Volume Method

Numerical Analyses of the Effect of the Freezing Wall on Ground Movement in the Artificial Ground Freezing Method

Numerical Analyses of the Effect of the Freezing Wall on Ground Movement in the Artificial Ground Freezing Method

Performance analysis of a gas turbine engine with intercooling and regeneration process - Part 1

Abstract Auxiliary systems, such as regeneration and intercooling, have been integrated with the primary gas generator to improve power production and fuel economy in modern gas turbine power plants. Implementing these techniques in turbine engines is challenging due to size, weight, and complex flow patterns. A solution is to use a turboprop engine with a smaller mass flow rate and simpler gas paths. The current study involves the numerical analysis of performance parameters namely, specific power (SP), thermal efficiency (η), and enthalpy based specific fuel consumption (EBSFC) of a turboprop engine using thermodynamic parameters namely, pressure ratio (PR), nozzle pressure ratio (NPR), turbine inlet temperature (TIT), regeneration efficiency (R), and intercooling efficiency (E). The results prove that the introduction of regeneration and intercooling showed significant improvement in the power developed, and reduced fuel consumption.

Understanding two‐phase flow behaviour: CFD Assessment of silicone oil–air and water–air in an intermediate vertical pipe

AbstractThe study utilized computational fluid dynamics (CFD) simulations employing the volume of fluid (VOF) model to analyze silicone oil–air flows in a vertical pipe with a diameter of 67 mm. Various structured meshes ensured grid independence, and the k‐ε realizable model addressed turbulence. The analysis characterized bubbly to annular flows, involving the evaluation of flow patterns, radial void fractions, void fraction time series, probability density functions (PDFs), power spectral densities (PSDs), and mean void fractions. Results indicated a transition from bubbly to annular flow with increasing gas velocities and notable changes in radial void fraction profiles. Void fraction exhibited significant variations with distinct flow patterns at constant liquid velocity. PDFs identified flow regimes, and PSDs revealed frequency patterns. CFD results were validated against experiments, demonstrating good agreement. The validated CFD model was utilized to investigate radial gas velocities and pressure drops, revealing a shift from uniform velocity distributions to irregular patterns and a decrease in total pressure drop with an increase in gas superficial velocity. The model was also applied to a water‐air system to explore two‐phase flow behaviour. The impact of superficial gas velocity on flow patterns and radial void fractions was studied through numerical analysis and compared with the silicone oil‐air system. Results showed that at extreme gas velocities (0.06 and 5.53 m/s), silicone oil exhibited bubbly and annular flows, while water displayed cap bubbly and churn flows. The significant variation in radial void fraction at these velocities emphasized the impact of fluid properties.

Use of lower tolerance limits for designing chair frames with round-end mortise and tenon joints

ABSTRACT In this study, the reliability of the mortise-tenon (MT) joints was examined experimentally and numerically. The joint strength has been determined empirically and numerically, but the reliability of the joint does not rely on a single asset – mean and standard deviation. The prediction of its strength also refers to a single value in the future population, but tolerance limits are related to a portion of the future population. Therefore, ensuring joint reliability comes into prominence not only for empirical data but also for theoretical and numerical analysis. For this purpose, the moment capacity of the T-shaped MT joints constructed of white oak was determined, and the lower tolerance limits (LTLs) approach was used to construct confidence/proportion (γ/β) levels for reliability. According to the results, the moment capacity of the MT joints was 341 Nm. The LTL values at 0.95/0.95, 0.99/0.95, 0.95/0.99, and 0.99/0.99 γ/β levels were 231, 226, 187 and 181 Nm, respectively. The normal stresses at each γ/β level were calculated based on the moment capacity and tenon sizes and were compared with the finite element method (FEM). Experimental and numerical results varied from 0.3% to 13.4%. Furthermore, a side frame was imposed to a vertical load of 1000 N on the front leg, and the moment of the joint on the side rail to the back post was measured (196 Nm). The side frame was modeled on ABAQUS – FEM software – and subjected to a moment of 196 Nm on the side rail. The theoretical and numerical results of stresses on joints differed from – 4.3% to 5.8%. The study showed that the reliability value is known, and; the joints could be designed by using FEM.

Numerical analysis on seismic behavior of a novel steel-timber composite frame column

Steel-timber composite structures are a novel hybrid structural system that combines the advantages of both steel and wood structures, holding great promise for various applications. In this paper, the seismic behaviors of steel- timber composite columns are investigated based on finite element analysis. The reliability of the finite element model is validated by quasi-static test results. Numerical analysis results indicate that the proposed steel- timber composite systems is with high ultimate bearing capacity, full hysteresis loops, and strong displacement ductility, demonstrating excellent seismic performance. The axial compression ratio, steel tube thickness, and flexural point height significantly influence the seismic resistance of the structure.

Numerical threshold stability analysis of a positivity-preserving IMEX numerical scheme for a nonlinear age-space structured SIR epidemic model

Numerical threshold stability analysis of a positivity-preserving IMEX numerical scheme for a nonlinear age-space structured SIR epidemic model

Numerical Analysis of Photonic Crystal Fiber-Based Biosensor for Glucose Level Detection in Urine and Blood

Numerical Analysis of Photonic Crystal Fiber-Based Biosensor for Glucose Level Detection in Urine and Blood

Numerical analysis of polyethylene based nano-enhanced phase change material in cylindrical storage system

Environmental sustainability encompasses various dimensions like waste management, energy conservation, and environmental impact. The use of waste plastic; Linear Low-density polyethylene (LLDPE) as a phase change material (PCM) offers a sustainable solution for energy and the environment. This study investigates LLDPE/ functionalize graphene composites for latent heat storage using a shell and helical coil for effective energy conversion. The simulation is carried out for constant flux and constant temperature heat supply to understand the influence of nano additives and geometrical parameters such as spiral coil diameter (Dc ), pitch (Pc ), and orientation of storage unit (θ). The result reveals that nano additive influence effectively and reduces the charging time approximately from 20 to 40% for 1–5% of nano-addition. Simulation results reveals that the spiral coil diameter is crucial for melting and heat transmission. The overall melting time is decreased by up to 56% by increasing the spiral coil diameter from 21 to 49 mm for LLDPE while the effect of pitch length variation is found not significant. The constant temperature heating at 160, 250 and 340°C gives effective results for charging time improvement. The geometrical orientations from 0 to 90 degrees report that the horizontal position is the best orientation for energy storage.

Efficient Strategic Pricing in a Dual-Channel Stackelberg Supply Chain: Incorporating Remanufacturing and Sales Commissions across Multiple Periods

The rise of e-commerce has significantly impacted consumer shopping habits, resulting in profit loss for traditional supply chains. In response to intense competition, numerous companies have transitioned their business models to embrace dual-channel configurations, seeking to captivate customers and increase their market share. Nonetheless, research on decentralized dual-channel supply chain configurations is scarce and predominantly concentrates on single-period pricing. This paper addresses this gap by employing Stackelberg’s game theory to investigate the multi-periodic pricing and remanufacturing decisions within a decentralized dual-channel supply chain with reverse logistics, specialized in the manufacturing and sales of pharmaceutical products. Moreover, this work considers that the online channel pays a sales commission to the pharmacy in return for the provided after-sales services, aiming to incorporate the aspect of sharing revenues. A mathematical formulation is proposed in a multi-periodic environment allowing us to simultaneously maximize the total profits of the manufacturer, the pharmacy and the online channel, by optimizing the pricing and remanufacturing strategies. Numerical analyses examine the customer purchasing preference’s effect on the demand and pricing decisions of each channel, the impact of the collection cost on the optimal remanufacturing strategy, and assess the break-even point of the total profits generated in both channels according to the sales commission. This study’s novelty lies in employing Stackelberg’s game theory to develop a mathematical formulation for the multi-periodic pricing and remanufacturing problem within a decentralized dual-channel supply chain, incorporating a sales commission between both distributors.

Task-oriented machine learning surrogates for tipping points of agent-based models

We present a machine learning framework bridging manifold learning, neural networks, Gaussian processes, and Equation-Free multiscale approach, for the construction of different types of effective reduced order models from detailed agent-based simulators and the systematic multiscale numerical analysis of their emergent dynamics. The specific tasks of interest here include the detection of tipping points, and the uncertainty quantification of rare events near them. Our illustrative examples are an event-driven, stochastic financial market model describing the mimetic behavior of traders, and a compartmental stochastic epidemic model on an Erdös-Rényi network. We contrast the pros and cons of the different types of surrogate models and the effort involved in learning them. Importantly, the proposed framework reveals that, around the tipping points, the emergent dynamics of both benchmark examples can be effectively described by a one-dimensional stochastic differential equation, thus revealing the intrinsic dimensionality of the normal form of the specific type of the tipping point. This allows a significant reduction in the computational cost of the tasks of interest.

Structural behavior of one-way slabs reinforced by a combination of GFRP and steel bars: An experimental and numerical investigation

Abstract Glass- fiber-reinforced polymer (GFRP) offers a significant alternative to steel in reinforced concrete, with superior corrosion and fire resistance. Though less ductile and more brittle in stress–strain behavior than steel, it is very helpful to combine GFRP with steel reinforcement that improves the structural behavior. This research investigates the flexural characteristics of a one-way slab reinforced by a combination of GFRP and steel reinforcement. Three identical concrete slabs ((1500 × 550 × 120) mm and 43 MPa) were tested under static load with GFRP replacement ratios of (0, 20, and 40)%. The experimental data were utilized to verify a numerical model. The experimental outcomes indicated a substantial impact of the GFRP replacement ratio on the failure mode. The failure mode was flexural, flexural-shear, and shear regarding the reference slab, 20%, and 40% replacement, respectively. GFRP replacement influenced ductility and ultimate load by (9.13 and 10.7)% and (−21 and 5.0)% for replacement ratio (20 and 40)%, respectively. Based on the numerical analysis, the parametric study (considerably affected the structural response. Failure mode changed to flexural, and shear-flexural concerning (20 and 40)%, respectively. The optimum load was characterized at 40%, while max toughness and ductility were achieved at 20%.