3 research outputs found

    Comparative study on Maxwell and Navier stokes fluid equations with pressure gradient over a flat plate for convective boundary layer flow and heat transfer

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    In this article, Maxwell fluid over a flat plate for convective boundary layer flow with pressure gradient parameter is considered. The aim of this study is to compare and analyze the effects of the presence and absence of λ (relaxation time), and also the effects of m (pressure gradient parameter) and Pr (Prandtl number) on the momentum and thermal boundary layer thicknesses. An approximation technique namely Homotopy Perturbation Method (HPM) has been used with an implementation of Adam and Gear Method’s algorithms. The obtained results have been compared for zero relaxation time and also pressure gradient parameter with the published work of Fathizadeh and Rashidi. The current outcomes are found to be in good agreement with the published results. Physical interpretations have been given for the effects of the m, Pr and β (Deborah number) with λ. This study will play an important role in industrial and engineering applications

    Two Stage Portfolio Selection and Optimization Model with the Hybrid Particle Swarm Optimization

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    The selection criteria play an important role in the portfolio optimization using any ratio model. In this paper, the authors have considered the mean return as profit and variance of return as risk on the asset return as selection criteria, as the first stage to optimize the selected portfolio. Furthermore, the sharp ratio (SR) has been considered to be the optimization ratio model. In this regard, the historical data taken from Shanghai Stock Exchange (SSE) has been considered. A metaheuristic technique has been developed, with financial tool box available in MATLAB and the particle swarm optimization (PSO) algorithm. Hence, called as the hybrid particle swarm optimization (HPSO) or can also be called as financial tool box particle swarm optimization (FTB-PSO). In this model, the budgets as constraint, where as two different models i.e. with and without short sale, have been considered. The obtained results have been compared with the existing literature and the proposed technique is found to be optimum and better in terms of profit

    4convective heat transfer in the boundary layer flow of a maxwell fluid over a flat plate using an approximation technique in the presence of pressure gradient

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    In this study, the effect of pressure gradient have been included for heat transfer in the boundary layer flow of Maxwell fluid over a flat plate.The solution of the problem is obtained with an application of algorithms of Adams Method (AM) and Gear Method (GM) with Homotopy Perturbation Method (HPM) as an approximation technique. This technique shows the outcomes of pressure gradient (m), Deborah number (β) and Prandtl number (Pr) in the boundary layer flow on temperature and velocity profiles, also the momentum and thermal boundary layer thickness and discussed. To obtain this objective, the momentum and energy equations of Maxwell are solved. The outcomes of HPM in the absence of relaxation time (λ) or Deborah number (β) and pressure gradient (m) (i.e. λ = β = m = 0) at Prandtl number Pr = 1 are in closed relation with the numerical results having the value of η∞ is around 5. Also it is found that the system is convergent, as a whole momentum and thermal boundary layer thicknesses becomes thinner and thinner. Importantly, some cooling effects of the Maxwell fluid over a flat plate for energy profile have been observed
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