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1
Content available Role of suction/injection on electromagnetohydrodynamics natural convection flow in a porous microchannel with electroosmotic effect
Oni Michael O., Rilwan Usman
International Journal of Applied Mechanics and Engineering
|
2023
|
Vol. 28, no. 4
94--113
EN
This paper examined the role of suction/injection on time-dependent electromagnetohydrodynamics (EMHD) natural (free) convection flow in a vertical microchannel with electroosmotic effect. With the aid of Laplace transformation method, the governing energy and momentum equations are converted from partial differential equation (PDE) into ordinary differential equation (ODE) to obtain fluid temperature and velocity in Laplace domain. The semi-analytical solutions of the velocity profile and temperature distribution have been derived using the Riemann sum approximation. After which a MATLAB program was written to study the effects of Prandlt number Pr, Hartmann number Ha, electric field strength on x and z directions (Ex and Sz) and Grashof number Gr in fluid velocity, temperature, skin-friction and mass flow rate in terms of line graphs. Result shows the role of suction/injection parameter alters the temperature distribution and velocity profile, so also how effective the governing parameters contribute to the flow formation.
2
Content available Heat transfer in oscillating flow through porous medium with dissipative heat
Guria M.
International Journal of Applied Mechanics and Engineering
|
2022
|
Vol. 27, no. 2
77--86
EN
In this paper, heat transfer in flow between two horizontal parallel porous plates through a porous medium when the upper plate oscillates in its own plane has been analyzed taking into account the effect of viscous dissipation. An increment in the Prandtl number or Reynolds number results in an increment of the temperature profile. With an increase in viscous dissipative heat the temperature distribution decreases.
3
Content available Unsteady MHD plane Couette-Poiseuille flow of fourthgrade fluid with thermal radiation, chemical reaction and suction effects
Joseph K. M., Ayankop-Andi E., Mohammed S. U.
International Journal of Applied Mechanics and Engineering
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2021
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Vol. 26, no. 4
77--98
EN
This study investigates the unsteady MHD flow of a fourth-grade fluid in a horizontal parallel plates channel. The upper plate is oscillating and moving while the bottom plate is stationary. Solutions for momentum, energy and concentration equations are obtained by the He-Laplace scheme. This method was also used by Idowu and Sani [12] and there is agreement with our results. The effect of various flow parameters controlling the physical situation is discussed with the aid of graphs. Significant results from this study show that velocity and temperature fields increase with the increase in the thermal radiation parameter, while velocity and concentric fields decrease with an increase in the chemical reaction parameter. Furthermore, velocity, temperature and concentric fields decrease with an increase in the suction parameter. It is also interesting to note that when 4S0=, our results will be in complete agreement with Idowu and Sani [12] results. The results of this work are applicable to industrial processes such as polymer extrusion of dye, draining of plastic films etc.
4
Content available Similarity solution of stagnation-point flow and heat transfer of a micropolar fluid towards a horizontal permeable exponentially elongating sheet with radiation, heat production / immersion
Parthiban R., Palani G.
International Journal of Applied Mechanics and Engineering
|
2021
|
Vol. 26, no. 4
179--191
EN
The current study aims to explore stagnation spot flow of a micropolar fluid about a plain linear exponentially expanding penetrable surface in the incidence of radiation and in-house heat production/immersion. Through similarity mapping, the mathematical modeling statements are transformed to ODE's and numerical results are found by shooting techniques. The impact of varying physical constants on momentum, micro-rotation and temperature is demonstrated through graphs. The computed measures including shear, couple stress, mass transfer and the local surface heat flux with distinct measures of factors involved in this proposed problem are presented through a table.
5
Content available A numerical approach to slip flow of a micropolar fluid above a flat permeable contracting surface
Parthiban R., Palani G., Tinker Seema, Sharma R. P.
International Journal of Applied Mechanics and Engineering
|
2021
|
Vol. 26, no. 2
173--185
EN
A plain linear penetrable contracting sheet with slip over a micro-polar liquid with a stagnation-point flow is analyzed. Through similarity mapping, the mathematical modeling statements are transformed as ODE’s and numerical results are found by shooting techniques. The varying impacts of physical quantities on the momentum, micro-rotation, and temperature were demonstrated through graphs. The computed measures including shear and couple stress with distinct measures of factors involved in this proposed problem are presented through a table.
6
Content available Transient heat and mass transfer of hydromagnetic effects on the flow past a porous medium with movable vertical permeablesheet
Okedoye A. M., Salawu S. O.
International Journal of Applied Mechanics and Engineering
|
2020
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Vol. 25, no. 4
175--190
EN
An unsteady flow of heat and species transport through a porous medium in an infinite movable vertical permeable flat surface is considered. The hydromagnetic chemical reactive fluid flow is stimulated by the thermal and solutant convection, and propelled by the movement of the surface. The formulated nonlinear flow equations in time space are solved analytically by asymptotic expansions to obtain solutions for the flow momentum, energy and chemical concentration for various thermo-physical parameters. The existence of flow characteristic is defined with the assistance of the flow parameters. In the study, the impact of some pertinent flow terms is reported and discussed. The study revealed that the species boundary layer increases with a generative chemical reaction and decreases with a destructive chemical reaction. Also, arise in the generative species reaction term reduces the flow momentum for the cooling surface. The impact of other flow governing parameters is displayed graphically as well as the fluid wall friction, wall energy and species gradients. The results of this study are important in chemical thermal engineering for monitoring processes to avoid solution blow up.
7
Content available remote Mechanism of biochar soil pore-gas-water interaction: gas properties of biochar-amended sandy soil at diferent degrees of compaction using KNN modeling
Garg Ankit, Huang He, Kushvaha Vinod, Madhushri Priyanka, Kamchoom Viroon, Wani Insha, Koshy Nevin, Zhu Hong-Hu
Acta Geophysica
|
2020
|
Vol. 68, no. 1
207--217
EN
Soil compaction has contrasting efect on soil strength (i.e., positive) and vegetation growth (i.e., negative), respectively. Biochar has been utilized mostly in combination with soils in both agricultural felds (i.e., loose soils) and geo-structures (i.e., dense soil slopes, landfll cover) for improving water retention due to its microporous structure. Biochar is also found to be useful to reduce gas permeability in compacted soil recently. However, the efciency of biochar in reducing gas permeability in loose and dense soils is rarely understood. The objective of this study is to analyze efects of compaction on gas permeability in soil at diferent degrees of compaction (i.e., 65%, 80% and 95%) and also diferent biochar amendment contents (0%, 5% and 10%). Another aim is to identify relative signifcance of parameters (soil suction, water content, biochar content and compaction) in afecting gas permeability. Experiments were conducted before applying k-nearest neighbor (KNN) modeling technique for identifying relative signifcance of parameters. Biochar was synthesized from a coastal invasive species (water hyacinth), which has relatively no infuence on food chain (as unlike in biochar produced from biomass such as rice husk, straw, peanut shell). Based on measurements and KNN modeling, it was found that gas permeability of biochar-amended soil is relatively lower than that of soil without amendment. It was found from KNN model that for denser soils, higher amount of soil suction is mobilized for a signifcant increase in gas permeability as compared to loose soils. Among all parameters, soil suction is found to be most infuential in afecting gas permeability followed by water content and compaction.
8
Content available Radiation absorption and chemical reaction effects on Rivlin-Ericksen flow past a vertical moving porous plate
Sravanthi C. S., Gorla R. S. R.
International Journal of Applied Mechanics and Engineering
|
2019
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Vol. 24, no. 3
675--689
EN
An analysis has been carried out to study the combined effects of radiation absorption and chemical reaction on an incompressible, electrically conducting and radiating flow of a Rivlin-Ericksen fluid along a semi-infinite vertical permeable moving plate in the presence of a transverse applied magnetic field. It is assumed that the suction velocity, the temperature and the concentration at the wall are exponentially varying with time. The dimensionless governing equations for this investigation are solved analytically using two-term harmonic and non-harmonic functions. A comparison is made with the available results in the literature for a special case and our results are in very good agreement with the known results. A parametric study of the physical parameters is made and results are presented through graphs and tables. The results indicate that the fluid velocity and temperature could be controlled by varying the radiation absorption.
9
Content available O potrzebie uwzględniania zasysania w praktycznych zagadnieniach filtracji wody podziemnej
Hauryłkiewicz J.
Przegląd Geologiczny
|
2018
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Vol. 66, nr 8
481--482
EN
Seven examples of issues have been pointed out, when one should take into account the suction exerting on groundwater by capillary attraction from fine sands or similar other fine soils.
10
Content available Unsteady flow through a porous medium due to noncoaxial rotations of a porous disk and a fluid at infinity subjected to a periodic suction
Guria M.
International Journal of Applied Mechanics and Engineering
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2018
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Vol. 23, no. 2
401--411
EN
The unsteady flow of a viscous incompressible fluid due to non-coaxial rotations of a porous disk and a fluid at infinity subjected to a periodic suction through a porous medium has been studied. The velocity field, shear stresses are obtained in closed form. The variations of primary and secondary velocities for different values of non dimensional parameters are depicted in figures.
11
Content available Bidirectionally stretched flow of Jeffrey liquid with nanoparticles, Rosseland radiation and variable thermal conductivity
Archana M., Gireesha B. J., Rashidi M. M., Prasannakumara B. C., Gorla R. S. R.
Archives of Thermodynamics
|
2018
|
Vol. 39, no 4
33–-57
EN
Heat and mass transfer stretched flow of an incompressible, electrically conducting Jeffrey fluid has been studied numerically. Nanoparticles are suspended in the base fluid and it has many applications such as cooling of engines, thermal absorption systems, lubricants fuel cell, nanodrug delivery system and so on. Temperature dependent variable thermal conductivity with Rosseland approximation is taken into account and suction effect is employed in the boundary conditions. The governing partial differential equations are first transformed into set of ordinary differential equations using selected similarity transformations, which are then solved numerically using Runge-Kutta-Felhberg fourth-fifth order method along with shooting technique. The flow, heat and mass transfer characteristics with local Nusselt number for various physical parameters are presented graphically and a detailed discussion regarding the effect of flow parameters on velocity and temperature profiles are provided. It is found that, increase of variable thermal conductivity, radiation, Brownian motion and thermophoresis parameter increases the rate of heat transfer. Local Nusselt number has been computed for various parameters and it is observed that, in the presence of variable thermal conductivity and Rosseland approximation, heat transfer characteristics are higher as compared to the constant thermal conductivity and linear thermal radiation.
12
Sprężysto-plastyczny model gruntu nienawodnionego
Fedczuk P.
Inżynieria i Budownictwo
|
2016
|
R. 72, nr 11
595--597
PL
Przedstawiono koncepcję sprężysto-plastycznego modelu częściowo nawodnionego gruntu. Model jest oparty na zmodyfikowanym równaniu powierzchni plastyczności Wheelera i Shivakumara. W przypadku zmiennej wartości ssania uogólnione prawo wzmocnienia wiąże przyrost plastycznej części wskaźnika porowatości z poziomem efektywnego naprężenia i ssania.
EN
The paper presents the concept of elasto-plastic model for partially saturated soil. The model operates equation of Wheeler and Shivakumar’s plastic surface. Generalized hardening rule, for changing value of suction, connects the increment of plastic part of void ratio with stress and suction levels.
13
Content available Rozwiązanie ograniczenia wydajności pompy wyporowej w celu uniknięcia kawitacji
Goszczak J., Werner A., Gauthier P., Pawelski Z.
Inżynieria Maszyn
|
2014
|
R. 19, z. 2
83--91
PL
W artykule przedstawiono sposób kontrolowanego ograniczania wydatku pompy wyporowej o niezmiennej objętości wyporu na jeden obrót, bez konieczności stosowania układów elektronicznych bądź dodatkowych elementów obwodu hydraulicznego za pompą. Zaproponowane rozwiązanie oparte jest na prawie Bernoulli’ego. Przy odpowiednio dużej wartości wydatku oleju, zostaje odsłonięte okno upustu oleju z komory tłoczenia na ssanie pompy. Wartość wydatku, przy którym następuje rozpoczęcie ograniczenia wydajności pompy można regulować dwoma sposobami - wartością napięcia wstępnego sprężyny znajdującej się w układzie, bądź miejscową zmianą przekroju kanału tłocznego. Dla obu sposobów regulacji przedstawiono doświadczalne charakterystyki obrazujące pracę układu przy różnych konfiguracjach. Zwrócono uwagę na możliwość pojawienia się zjawiska kawitacji przy konstrukcji układu ssawnego stwarzającego duże opory na ssaniu. Ograniczenie wydatku pompy poniżej granicy kawitacji jest jednym z możliwych sposobów aplikacji układu omawianego w niniejszym artykule. W podsumowaniu sformułowano wnioski nasuwające się z przedstawionych badań wraz z zestawieniem rezultatów badań, oraz zauważonymi na ich podstawie ograniczeniami w działaniu układu.
EN
A technical solution has been proposed that ensures oil drain from the discharge chamber to the pump inlet. The piston of a relief valve is controlled by a differential pressure resulting from Bernoulli effect. The start value of oil draining is to be controlled by the spring initial deflection and modification of the flow section in the outlet channel of the pump.
14
Content available Three-dimensional oscillating flow between two parallel plates through a porous medium
Guria M., Ghara N., Jana R. N.
International Journal of Applied Mechanics and Engineering
|
2013
|
Vol. 18, no. 4
1025--1037
EN
An unsteady Couette flow between two parallel plates when upper plates oscillates in its own plane and is subjected to a constant suction and the lower plate to a injection velocity distribution through the porous medium has been analyzed. The approximate solution has been obtained using perturbation technique. It is seen that the primary velocity increases whereas the secondary velocity decreases with an increase in permeability parameter. It is also found that the primary velocity increases with an increase in the Reynolds number as well as the suction parameter. The magnitude of the secondary velocity increases near the stationary plate but decreases near the oscillating plate with an increase in the Reynolds number. Whereas, it increases with an increase in the suction parameter.
15
Content available remote The effect of suction on magnetohydrodynamic forced flow of a viscous electrically conducting fluid through a porous medium induced by a rotating disk
Sharma B. K., Jha A. K., Chaudhary R. C.
International Journal of Applied Mechanics and Engineering
|
2012
|
Vol. 17, no. 4
1297-1308
EN
The present paper investigates the steady MHD forced flow of an incompressible viscous electrically conducting fluid, due to an infinite rotating disk bounded by a porous medium. A uniform suction is applied on the upper disk. It is assumed that the flow between the disk and the porous medium is governed by Navier-Stokes equations and that in the porous medium by Brinkman equations. Flows in the two regions are matched at the interface by assuming that the velocity and stress components are continuous at it. At the interface (porous medium-clear fluid boundary), a modified set of boundary conditions suggested by Ochao-Tapia and Whittaker is applied. Assuming constant suction at the disk surface, analytical expressions for the velocity and shearing stress are calculated and effects of various parameters upon them are examined.
16
Content available Elasto-plastic model of unsaturated soil
Fedczuk P.
AGH Journal of Mining and Geoengineering
|
2012
|
Vol. 36, no. 2
137-144
EN
The paper presents the concept of an elasto-plastic model for partially saturated soil. Elastic properties are described by the classical elastic rule, taking into consideration the effective stresses. Plastic properties are defined by extension of the critical state theory which also takes the suction effect into consideration. The behaviour of soil is described by the extended incremental elasto-plastic constitutive relation (in form "effective stress - strain and suction" relationship). The model operates the equation of the Wheeler and Sivakumar's plastic surface. The generalized hardening rule (for the changing value of suction) connects the increment of the plastic part of the void ratio with stress and suction levels.
PL
W pracy prezentuje się koncepcję sprężysto-plastycznego modelu częściowo nawodnionego gruntu. Sprężyste własności gruntu opisuje klasyczne równanie sprężystości, uwzględniającego efektywne naprężenia. Plastyczne własności definiuje rozwinięta teoria stanu krytycznego uwzględniająca efekt ssania. Zachowanie gruntu opisuje rozszerzone przyrostowe prawo sprężysto-plastyczności (w formie zależności "efektywne naprężenie - odkształcenie i ssanie"). Model operuje zmodyfikowanym równaniem powierzchni plastyczności Wheelera i Sivakumara. Uogólnione prawo wzmocnienia (dla zmiennej wartości ssania) wiąże przyrost plastycznej części wskaźnika porowatości z poziomem efektywnego naprężenia i ssania.
17
Content available remote Free convective heat and mass transfer flow over a non-isothermal stretching sheet with added heat source and thermal diffusion in a saturated porous medium
Pravin V. K., Rajagopal K., Veena P. H., Umesh K. S.
International Journal of Applied Mechanics and Engineering
|
2011
|
Vol. 16, no 1
177-194
EN
The present paper deals with the study of MHD free convection and mass transfer flow of an incompressible viscous fluid past a continuously moving non-isothermal infinite vertical sheet in non-Darcy porous media in the presence of large suction under the influence of uniform magnetic field considering heat source and thermal diffusion with viscous dissipation, inertia term and stress work. Introducing the usual similarity transformations, the equations of momentum, energy and concentration are made linear. To obtain the solution of the problem, ordinary differential equations are solved analytically. The effects of various physical parameters such as the magnetic parameter, permeability parameter, inertia parameter, suction/blowing parameter on heat transfer characteristics are analysed. One of the important findings of our study is that of increasing the value of the inertia parameter k3 decreases the velocity profile and to increase the temperature profile.
18
Content available remote Three dimensional MHD free convection flow and heat transfer through a vertical channel
Guria M., Ghara N., Jana R. N.
International Journal of Applied Mechanics and Engineering
|
2010
|
Vol. 15, no 4
1047-1063
EN
An analysis is made on the three dimensional MHD flow of a viscous incompressible fluid through a vertical channel in the presence of a uniform injection on the right plate and the left plate is subject to a periodic suction. The velocity and temperature fields are derived using the perturbation technique. It is observed that the primary velocity increases near the left plate and decreases near the right plate with an increase in the Reynolds number while it decreases with an increase in the magnetic parameter. It is seen that with an increase in the Prandtl number the primary velocity decreases whereas it increases with an increase in the Grashof number. It is seen that the magnitude of the secondary velocity increases in the range […] and thereafter decreases with an increase in the Reynolds number. It is also seen that the shear stress due to primary flow increases with an increase in either the Grashof number or Reynolds number but decreases with an increase in the Prandtl number. It is seen that the shear stress […] at the plate […] decreases with an increase in the magnetic parameter. Also, the magnitude of the shear stress due to cross flow increases with an increase in the Reynolds number. It is seen that the temperature at any point decreases with an increase in either the Prandtl number or Reynolds number. The rate of heat transfer in terms of the Nusselt number is also studied. Dimensional variables are indicated by dropping the asterisk and are defined in Eq.(2.8).
19
Content available remote Steady axisymmetric flow and heat transfer of micropolar fluid over a vertical permeable slender cylinder in the presence of thermal radiation
Mansour M. A., Mohamed R. A., Abd Elaziz M. M., Ahmed S. E.
International Journal of Applied Mechanics and Engineering
|
2010
|
Vol. 15, no 4
1185-1203
EN
The effects of thermal radiation and suction/blowing on an axisymmetric flow and heat transfer of a micropolar fluid over a vertical slender cylinder are analyzed. The partial differential equations governing the flow and heat transfer have been transformed to ordinary differential equations by using similarity transformations which are then solved numerically. The numerical results are validated by favorable comparisons with previously published results. The cases of buoyancy-assisted flow, pure mixed convection, buoyancy opposed flow, permeable cylinder, impermeable cylinder, Newtonian fluids and non-Newtonian fluids as well as the case which represents concentrated particle flow in which the microelements close to the wall surface are unable to rotate and the case which indicates vanishing of an antisymmetric part of the stress tensor are considered. A parametric study of the governing parameters, namely the buoyancy parameter, suction/injection parameter, radiation parameter, vortex viscosity parameter, curvature parameter and microgyration boundary conditions parameter on the linear velocity, angular velocity and temperature as well as the wall stress, wall couple stress and the rate of heat transfer is conducted. A selected set of numerical results is presented graphically and discussed.
20
Content available remote Radiation effect on three dimensional vertical channel flow
Guria M., Ghara N., Jana R. N.
International Journal of Applied Mechanics and Engineering
|
2010
|
Vol. 15, no 4
1065-1081
EN
An analysis is made of the three dimensional flow of viscous incompressible fluid through a vertical channel in the presence of a uniform injection on the right plate and a periodic suction velocity distribution on the left plate with radiation effect. The velocity and temperature fields are derived using the perturbation technique. It is found that the primary velocity decreases with an increase in the radiation parameter. It is seen that the shear stress due to primary flow increases with an increase in the Reynolds number but decreases with an increase in the radiation parameter. It is also seen that the temperature decreases with an increase in the radiation parameter. The rate of heat transfer in terms of the Nusselt number is also studied.
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