Simulations of micropolar nanofluid-equipped natural convective-driven flow in a cavity

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Naeem Ullah ◽  
Sohail Nadeem ◽  
Luthais McCash ◽  
Anber Saleem ◽  
Alibek Issakhov
Keyword(s):  
Flow Analysis ◽  
Internal Flow ◽  
Viscosity Coefficient ◽  
Mathematical Framework ◽  
Flow Profile ◽  
Content Type ◽  
Contour Maps ◽  
Linear Partial Differential Equations ◽  
Micropolar Nanofluid ◽  
Heated Source

Purpose This paper aims to focus on the natural convective flow analysis of micropolar nanofluid fluid in a rectangular vertical container. A heated source is placed in the lower wall to generate the internal flow. In further assumptions, the left/right wall are kept cool, while the upper and lower remaining portions are insulated. Free convection prevails in the regime because of thermal difference in-between the lower warmer and upper colder region. Design/methodology/approach The physical setup owns mathematical framework in-terms of non-linear partial differential equations. For the solution purpose of the differential system, finite volume method is adopted. The interesting features of the flow along with thermal transportation involve both translational and rotational movement of fluid particles. Findings Performing the simulations towards flow controlling variables the outputs are put together in contour maps and line graphs. It is indicated that the variations in flow profile mass concentration and temperature field augments at higher Rayleigh parameter because of stronger buoyancy effects. Higher viscosity coefficient implies decrease in flow and thermal transportation. Further, the average heat transfer rate also grows by increasing both the Rayleigh parameter and heated source length. Originality/value To the best of the authors’ knowledge, no such study has been addressed yet. Further, the results are validated by comparing with previously published work.

Internal Flow Analysis on Sweeping Jet Actuator

2019 ◽  
Author(s):  
Sushanth Gowda B C ◽  
Vinuth N ◽  
Poornananda T ◽  
Dhanush G J, ◽  
T Paramesh
Keyword(s):  
Flow Analysis ◽  
Internal Flow

Generation of steady longitudinal vortices in hypersonic boundary layer

2013 ◽  
Vol 729 ◽  
pp. 702-731 ◽  
Author(s):  
A. I. Ruban ◽  
M. A. Kravtsova
Keyword(s):  
Boundary Layer ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Viscosity Coefficient ◽  
Momentum Equation ◽  
The Body ◽  
Nonlinear Behaviour ◽  
Hypersonic Boundary Layer ◽  
Stagnation Temperature ◽  
Characteristic Distance

AbstractIn this paper we study the three-dimensional perturbations produced in a hypersonic boundary layer by a small wall roughness. The flow analysis is performed under the assumption that the Reynolds number, $R{e}_{0} = {\rho }_{\infty } {V}_{\infty } L/ {\mu }_{0} $, and Mach number, ${M}_{\infty } = {V}_{\infty } / {a}_{\infty } $, are large, but the hypersonic interaction parameter, $\chi = { M}_{\infty }^{2} R{ e}_{0}^{- 1/ 2} $, is small. Here ${V}_{\infty } $, ${\rho }_{\infty } $ and ${a}_{\infty } $ are the flow velocity, gas density and speed of sound in the free stream, ${\mu }_{0} $ is the dynamic viscosity coefficient at the ‘stagnation temperature’, and $L$ is the characteristic distance the boundary layer develops along the body surface before encountering a roughness. We choose the longitudinal and spanwise dimensions of the roughness to be $O({\chi }^{3/ 4} )$ quantities. In this case the flow field around the roughness may be described in the framework of the hypersonic viscous–inviscid interaction theory, also known as the triple-deck model. Our main interest in this paper is the nonlinear behaviour of the perturbations. We study these by means of numerical solution of the triple-deck equations, for which purpose a modification of the ‘skewed shear’ technique suggested by Smith (United Technologies Research Center Tech. Rep. 83-46, 1983) has been used. The technique requires global iterations to adjust the viscous and inviscid parts of the flow. Convergence of such iterations is known to be a major problem in viscous–inviscid calculations. In order to achieve improved stability of the method, both the momentum equation for the viscous part of the flow, and the equations describing the interaction with the flow outside the boundary layer, are treated implicitly in this study. The calculations confirm the fact that in this sort of flow the perturbations are capable of propagating upstream in the boundary layer, resulting in a perturbation field which surrounds the roughness on all sides. We found that the perturbations decay rather fast with the distance from the roughness everywhere except in the wake behind the roughness. We found that if the height of the roughness is small, then the perturbations also decay in the wake, though much more slowly than outside the wake. However, if the roughness height exceeds some critical value, then two symmetric counter-rotating vortices form in the wake. They appear to support themselves and grow as the distance from the roughness increases.

INFINITI HR – professional employer organizations

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Susan White ◽  
Karen Hallows
Keyword(s):  
Financial Analysis ◽  
Flow Analysis ◽  
Capital Budgeting ◽  
Discounted Cash Flow ◽  
Content Type ◽  
Analysis And Evaluation ◽  
Academic Level ◽  
Course Of Action ◽  
Basic Capital ◽  
Current Events

Theoretical basis Students need to know basic capital budgeting techniques to value INFINITI and its competitors. Issues include how to: handle taxes in a discounted cash flow analysis when valuing an S Corp. where incentives depend on current (known) and future (unknown) tax provisions; value a firm using comparable multiples analysis and transactions data; assess the costs and benefits of acquiring a firm versus being acquired; and analyze an industry and perform a ratio and financial statement analysis. Research methodology The case information was obtained through interviews with co-founder Mark Schwaiger. In addition, the authors researched industry and comparable company data, along with current events relating to the professional employer organization (PEO). Financial data was obtained from the owners and competitor data was obtained from Thomson One and Bloomberg. Case overview/synopsis INFINITI HR was a PEO providing comprehensive human resources to their clients. Co-founders Scott Smrkovski and Mark Schwaiger were at a crossroads at the end of 2015 trying to determine the best course of action to take with their company to grow and prosper. One option was for INFINITI to be acquired by a larger company and the second option was for INFINITI acquire a smaller company. In this case, students have the opportunity to do a financial analysis and evaluation of INFINITI and its competitors to determine which option is the best. Complexity academic level This case is intended for an advanced undergraduate or an MBA corporate finance class.

Internal Flow Analysis in a Two-Channel Pump Used for Salt Transportation

2018 ◽  
Author(s):  
Jiaqi Wang ◽  
Xianwu Luo ◽  
Wanming Li ◽  
Bin Ji
Keyword(s):  
Particle Concentration ◽  
Flow Analysis ◽  
Internal Flow ◽  
Leading Edge ◽  
Pressure Side ◽  
Operation Condition ◽  
Static State ◽  
Erosion Risk ◽  
Salt Particle ◽  
Blade Leading Edge

Two-channel pumps usually have very complicated flow field due to the special impeller geometry. The present paper treats the internal flow analysis based on numerical simulation so as to investigate the pumping performance and passage erosion for a two-channel centrifugal pump used for transporting salt particles. The static state flows are calculated by applying RANS method and k-omega SST turbulence model. The numerical results indicate that there are strong circulation flows near the impeller inlet and blade pressure side, and zones with high turbulent kinetic energy near impeller exit when the pump is operated under the designed flow rate i.e. Qd. Pressure decay is also found at the rear part of blade pressure side. At the operation condition of 1.3Qd, the internal flow becomes better. Further, the numerical analysis based on Eulerian-Lagrangian method shows the trajectory of salt particle, salt particle concentration and erosion rate in the pump. It is noted that the salt particles go smoothly in the flow passage due to the large section size of the pump, and there is severe erosion at the blade leading edge and the wall of volute casing due to strong impingement and high particle concentration. Thus, these areas such as blade leading edge and the wall of volute casing are the zones with high erosion risk in the two-channel pump.

Modeling and optimization of road transport facility operations

2014 ◽  
Vol 12 (3) ◽  
pp. 268-285 ◽  
Author(s):  
Andy H.F. Chow ◽  
Ying Li
Keyword(s):  
Traffic Flow ◽  
Travel Demand ◽  
Road Transport ◽  
Transport Infrastructure ◽  
Computational Time ◽  
Mathematical Framework ◽  
Global Optimality ◽  
Content Type ◽  
Transport Facility ◽  
Traffic Theory

Purpose – This paper aims to present a linear mathematical framework for modeling and optimizing road transport infrastructure. The framework assesses and optimizes performance of existing transport facility rather than relying on building new roads for the ever-increasing travel demand. Design/methodology/approach – The mathematical framework is built upon a traffic model called Cell Transmission Model (CTM). CTM describes the relationship and evolution of traffic flow and concentration over space and time. The model is parsimonious and accurate in predicting traffic dynamics. More importantly, the traffic flow model is piecewise linear with which the corresponding transport facility optimization problem can be formulated as a Linear Programming (LP) problem and solved by established solution algorithm for global optimality. Findings – We select a section on England Motorway M25 as a case study. With traffic data, we first calibrate the CTM, and we are able to produce traffic estimation with a reasonable error rate of 12 per cent. The corresponding LP then seeks an optimal ramp metering strategy that minimizes the delay on the motorway. It is shown that an optimal and practical strategy can be derived which reduces the motorway delay by 10 per cent without significantly hurting the surrounding connectors. Originality/value – Instead of the tedious microscopic models used by many traditional tools, the underlying CTM is parsimonious and reliable. The tools developed herein are based upon plausible traffic theory and will be accessible for a wide range of users. The LP formulation can be easily implemented and solved for optimal and practical control strategies for real-world transport networks by using existing computer software (CPLEX) within reasonable computational time. The present work will certainly contribute to the sustainable development of transport facility.

scholarly journals How to measure food loss and waste? A material flow analysis application

2020 ◽  
Vol 123 (1) ◽  
pp. 67-85 ◽  
Author(s):  
Vera Amicarelli ◽  
Christian Bux ◽  
Giovanni Lagioia
Keyword(s):  
Food Waste ◽  
Material Flow ◽  
Animal Feed ◽  
Flow Analysis ◽  
Material Balance ◽  
Material Flow Analysis ◽  
Potato Industry ◽  
Poultry Feed ◽  
Content Type ◽  
Food Loss

PurposeThe purpose of this paper is to measure food loss and waste by material flow analysis (MFA) tool. Applying this methodology, the authors estimate wastage-related losses and discuss opportunities for more circular and sustainable practices in the Italian potato industry.Design/methodology/approachMFA is applied to two specific typologies as follows: ready-to-eat (chips) and dried potato products produced in Italy. The analysis refers to the year 2017 as the complete dataset useful for this study includes measurements until this year. A bottom-up and top-down mixed approach is applied, and functional unit refers to 1 t of potatoes consumed as final product.FindingsMFA is applied to quantify and qualify material balance associated with 1 t of potatoes consumed as final product. In Italy, in 2017, more than 22,000 t of fresh tubers were lost, including 3,500–4,800 t of starch, equivalent to 52,800–72,600 GJs. Moreover, fewer than 23,000 t of skins and scraps were produced within industrial plants, not available for food but suitable for animal feed (dry skins are an excellent carbohydrates source in cattle and poultry feed), starch industry and bioenergy production (biogas and/or bioethanol).Originality/valueThis research is one of the few studies proposing MFA methodology as a tool to measure food waste. This analysis shows its utility in terms of food waste quality/quantity evaluation, supporting both company management and policymakers.

The impacts of non-uniform magnetic field on free convection heat transfer of a magnetizable micropolar nanofluid

2019 ◽  
Vol 29 (10) ◽  
pp. 3685-3706
Author(s):  
Zafar Namazian ◽  
S.A.M. Mehryan
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Volume Fraction ◽  
Convection Heat Transfer ◽  
Content Type ◽  
Viscosity Parameter ◽  
Micropolar Nanofluid ◽  
Free Convection Heat

Purpose The purpose of this study is to numerically study the heat transfer of free convection of a magnetizable micropolar nanofluid inside a semicircular enclosure. Design/methodology/approach The flow domain is under simultaneous influences of two non-uniform magnetic fields generated by current carrying wires. The directions of the currents are the same. Although the geometry is symmetric, it is physically asymmetric. The impacts of key parameters, including Rayleigh number Ra = 103-106, Hartman number Ha = 0-50, vortex viscosity parameter Δ = 0-4, nanoparticles volume fraction φ = 0-0.04 and magnetic number Mnf = 0-1000, on the macro- and micro-scales flows, temperature and heat transfer rate are studied. Finding The outcomes show that dispersing of the nanoparticles in the host fluid increases the strength of macro- and micro-scale flows. When Mnf = 0, the increment of the vortex viscosity parameter increases the strength of the particles micro-rotations, while this characteristic is decreased by growing Δ for Mnf ≠ 0. The increment of Δ and Ha decreases the rate of heat transfer. The increment of Ha decreases the enhancement percentage of heat transfer rate because of dispersing nanoparticles, known as En parameter. In addition, the value of Δ has no effect on En. Moreover, the average Nusselt number Nuavg and En remain constant by increasing the magnetic number Mnf for different volume fraction values. Originality/value The authors believe that all of the results, both numerical and asymptotic, are original and have not been published elsewhere yet.

A multi-methodological approach for assessing sustainability of urban projects

2015 ◽  
Vol 26 (1) ◽  
pp. 138-154 ◽  
Author(s):  
Marta Bottero
Keyword(s):  
Swot Analysis ◽  
Planning Process ◽  
Methodological Approach ◽  
Hybrid Approach ◽  
Flow Analysis ◽  
Multicriteria Analysis ◽  
Discounted Cash Flow ◽  
Content Type ◽  
Definition Of ◽  
The City

Purpose – The purpose of this paper is to propose a multi-methodological approach for assessing the sustainability of urban projects. The proposed framework has the objective of addressing the different dimensions involved in the analysis (economic, environmental, social, technological, cultural, etc.), following the subsequent phases for the definition of the projects (from a very general masterplan to more detailed preliminary projects). Design/methodology/approach – The multi-methodological approach is organized according to subsequent steps, involving the application of different evaluation methods, namely SWOT analysis, multicriteria analysis, discounted cash flow analysis and sensitivity analysis. With the aim of better illustrating the proposed approach, the method is applied on a real case concerning the project of a new boulevard in the city of Skopje. Findings – The proposed approach resulted to be successful in structuring the complex planning context and in increasing and improving the information for the project, thus acting as a learning process. Originality/value – The paper is based on the experimentation of an hybrid approach for addressing planning process. The multi-methodological framework can be useful in supporting decision making process in the domain of urban projects. In this sense, the proposed framework is able to communicate the planners’, designers’ and decision maker’s perspectives, to enhance transparency in the decision process and thus to increase acceptance.

Three-Dimensional Calculation of Wall Boundary Layer Flows in Turbomachines

1987 ◽  
Author(s):  
W. L. Lindsay ◽  
H. B. Carrick ◽  
J. H. Horlock
Keyword(s):  
Boundary Layer ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Cross Flow ◽  
Flow Profile ◽  
Boundary Layer Flows ◽  
Wall Boundary Layer ◽  
Boundary Layer Development ◽  
Flow Through ◽  
The Cross

An integral method of calculating the three-dimensional turbulent boundary layer development through the blade rows of turbomachines is described. It is based on the solution of simultaneous equations for (i) & (ii) the growth of streamwise and cross-flow momentum thicknesses; (iii) entrainment; (iv) the wall shear stress; (v) the position of maximum cross-flow. The velocity profile of the streamwise boundary layer is assumed to be that described by Coles. The cross-flow profile is assumed to be the simple form suggested by Johnston, but modified by the effect of bounding blade surfaces, which restrict the cross-flow. The momentum equations include expressions for “force-defect” terms which are also based on secondary flow analysis. Calculations of the flow through a set of guide vanes of low deflection show good agreement with experimental results; however, attempts to calculate flows of higher deflection are found to be less successful.

Unsteady Flow Simulations of a Transonic Nozzle and Cascade for a Time-Dependent Boundary Flow

2002 ◽  
Author(s):  
Erdal Turkbeyler
Keyword(s):  
Shock Wave ◽  
Unsteady Flow ◽  
Flow Analysis ◽  
Internal Flow ◽  
Wave Mode ◽  
Accurate Solution ◽  
Single Step ◽  
Integration Scheme ◽  
Inlet Flow ◽  
Flow Fluctuations

In this study we investigate unsteady compressible internal flow caused by flow fluctuations at an inlet or outlet flow-boundary. A finite-volume time-marching method has been developed for the unsteady flow analysis. This paper presents the proposed method and reports the results of a numerical investigation into the effects of a time-varying back pressure to a two-dimensional transonic nozzle and of a pulsating inlet flow to a transonic three-dimensional cascade of tapered blades. The computational model is based on a solution of the unsteady Euler equations for compressible flow. The time accurate solution is advanced by an explicit single-step second order time integration scheme. It has been found that the flow fluctuations at flow boundaries can cause strong unsteady effects on the operation of nozzles and cascades. Two modes of operation have been predicted for the unsteady flow in the nozzle: an upstream moving shock wave (mode-A) and an oscillating shock wave (mode-B). The results for the cascade have shown that the pulsating inlet flow causes the shock wave to originate, to move upstream and weaken over the period; the supersonic region on the blade surface varies continuously. The instantaneous mass flow rates and shock motions have been determined for them; they are important for their design and performance calculations.

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