scholarly journals Nonlinear Mixed Convective Flow over a Moving Yawed Cylinder Driven by Buoyancy

Mathematics ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1275
Author(s):  
Prabhugouda M. Patil ◽  
Hadapad F. Shankar ◽  
Mikhail A. Sheremet
Keyword(s):  
Nusselt Number ◽  
Sherwood Number ◽  
Velocity Ratio ◽  
Velocity Profiles ◽  
Practical Significance ◽  
Finite Difference Schemes ◽  
Species Concentration ◽  
Buoyancy Flow ◽  
Yaw Angle ◽  
Flow Case

The fluid flow over a yawed cylinder is useful in understanding practical significance for undersea applications, for example, managing transference and/or separation of the boundary layer above submerged blocks and in suppressing recirculating bubbles. The present analysis examines nonlinear mixed convection flow past a moving yawed cylinder with diffusion of liquid hydrogen. The coupled nonlinear control relations and the border restrictions pertinent to the present flow problem are nondimensionalized by using nonsimilar reduction. Further, implicit finite difference schemes and Quasilinearization methods are employed to solve the nondimensional governing equations. Impact of several nondimensional parameters of the analysis on the dimensionless velocity, temperature and species concentration patterns and also on Nusselt number, Sherwood number and friction parameter defined at the cylinder shell is analyzed through numerical results presented in various graphs. Velocity profiles can be enhanced, and the coefficients of friction at the surface can be reduced, for increasing values of velocity ratio parameters along chordwise as well as spanwise directions. Species concentration profile is reduced, while the Sherwood number is enhanced, for growth of the Schmidt number and yaw angles. Furthermore, for an increasing value of yaw angle, skin-friction coefficient in chordwise direction diminishes in opposing buoyancy flow case, whereas the results exhibit the opposite trend in assisting buoyancy flow case. Moreover, very importantly, for increasing magnitude of nonlinear convection characteristic, the liquid velocity and surface friction enhance in spanwise direction. Further, for increasing magnitude of combined convection characteristics, velocity profiles and coefficient of friction at the surface enhance in both spanwise and chordwise directions. Moreover, we have observed that there is no deviation for zero yaw angle in Nusselt number and Sherwood number.

Double Diffusive Marangoni Convection Flow of Electrically Conducting Fluid in a Square Cavity With Chemical Reaction

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
M. Saleem ◽  
M. A. Hossain ◽  
Suvash C. Saha
Keyword(s):  
Magnetic Field ◽  
Nusselt Number ◽  
Sherwood Number ◽  
Average Nusselt Number ◽  
Marangoni Convection ◽  
Convection Flow ◽  
Square Cavity ◽  
Electrically Conducting ◽  
Electrically Conducting Fluid ◽  
Double Diffusive

Double diffusive Marangoni convection flow of viscous incompressible electrically conducting fluid in a square cavity is studied in this paper by taking into consideration of the effect of applied magnetic field in arbitrary direction and the chemical reaction. The governing equations are solved numerically by using alternate direct implicit (ADI) method together with the successive over relaxation (SOR) technique. The flow pattern with the effect of governing parameters, namely the buoyancy ratio W, diffusocapillary ratio w, and the Hartmann number Ha, is investigated. It is revealed from the numerical simulations that the average Nusselt number decreases; whereas the average Sherwood number increases as the orientation of magnetic field is shifted from horizontal to vertical. Moreover, the effect of buoyancy due to species concentration on the flow is stronger than the one due to thermal buoyancy. The increase in diffusocapillary parameter, w causes the average Nusselt number to decrease, and average Sherwood number to increase.

scholarly journals EFFECT OF HEAT AND MASS TRANSFER AND THERMAL RADIATION ON A STEADY MHD CONVECTIVE FLOW WITH VISCOUS DISSIPATION AND SUCTION/INJECTION

2022 ◽  
Vol 52 (1) ◽  
pp. 35-41
Author(s):  
Silpisikha Goswami ◽  
Kamalesh Kumar Pandit ◽  
Dipak Sarma
Keyword(s):  
Nusselt Number ◽  
Thermal Radiation ◽  
Temperature Profile ◽  
Skin Friction ◽  
Viscous Dissipation ◽  
Sherwood Number ◽  
Fluid Velocity ◽  
Physical Parameters ◽  
Flow Equations ◽  
The Impact

Our motive is to examine the impact of thermal radiation and suction or injection with viscous dissipation on an MHD boundary layer flow past a vertical porous stretched sheet immersed in a porous medium. The set of the flow equations is converted into a set of non-linear ordinary differential equations by using similarity transformation. We use Runge Kutta method and shooting technique in MATLAB Package to solve the set of equations. The impact of non-dimensional physical parameters on flow profiles is analysed and depicted in graphs. We observe the influence of non-dimensional physical quantities on the Nusselt number, the Sherwood number, and skin friction and presented in tables. A comparison of the obtained numerical results with existing results in a limiting sense is also presented. We enhance radiation to observe the deceleration of fluid velocity and temperature profile for both suction and injection. While enhancing porosity parameter accelerates velocity whereas decelerates temperature profile. As the heat source parameter increases, the temperature of the fluid decreases for both suction and injection, it has been found. With the increasing values of the radiation parameter, the skin friction and heat transfer rate decreases. Increasing magnetic parameter decelerates the skin friction, Nusselt number, and Sherwood number.

scholarly journals New exact and numerical solutions for the effect of suction or injection on flow of nanofluids past a stretching sheet

2019 ◽  
Vol 8 (1) ◽  
pp. 172-178
Author(s):  
Nader Y. Abd Elazem
Keyword(s):  
Nusselt Number ◽  
Exact Solutions ◽  
Sherwood Number ◽  
Stretching Sheet ◽  
Numerical Solutions ◽  
Volume Fraction ◽  
Lewis Number ◽  
Suction Or Injection ◽  
Wall Mass ◽  
Good Agreement

Abstract The flow of nanofluids past a stretching sheet has attracted much attention due to its wide applications in industry and engineering. Theoretical and numerical solutions have been discussed in this paper for studying the effect of suction or injection on flow of nanofluids past a stretching sheet. In the absence of thermophoresis the analytical exact solution of the stream function was obtained in terms of exponential function, while the exact solutions for temperature and nanoparticle volume fraction were obtained in terms of the generalized incomplete gamma function. In addition, in the presence of thermophoresis, the exact solutions are not available. Therefore, the numerical results, carried out by using Chebyshev collocation method (ChCM). It is found that a good agreement exists between the present results and with those published works. Useful results for temperature profile, concentration profile, reduced Nusselt number and reduced Sherwood number are discussed in details graphically. It was also demonstrated that both temperature and concentration profiles decrease by an increase from injection to suction. Finally, the present results showed that increase of the wall mass transfer from injection to suction decreased both reduced Nusselt number and the reduced Sherwood number when Brownian motion parameter and Lewis number increased.

scholarly journals Computation of electroconductive gyrotactic bioconvection under nonuniform magnetic field: Simulation of smart bio-nanopolymer coatings for solar energy

2020 ◽  
Vol 34 (05) ◽  
pp. 2050028 ◽  
Author(s):  
Madhu Aneja ◽  
Sapna Sharma ◽  
Sireetorn Kuharat ◽  
O. Anwar Beg
Keyword(s):  
Magnetic Field ◽  
Nusselt Number ◽  
Brownian Motion ◽  
Differential Equations ◽  
Sherwood Number ◽  
Nonuniform Magnetic Field ◽  
Ohmic Dissipation ◽  
Local Skin ◽  
Brownian Motion And Thermophoresis ◽  
Micro Organisms

The water-based bioconvection of a nanofluid containing motile gyrotactic micro-organisms (moves under the effects of gravity) over a nonlinear inclined stretching sheet in the presence of a nonuniform magnetic field has been investigated. This regime is encountered in the bio-nanomaterial electroconductive polymeric processing systems currently being considered for third-generation organic solar coatings, anti-fouling marine coatings, etc. Oberbeck–Boussinesq approximation along with ohmic dissipation (Joule heating) is considered in the problem. The governing equations of the flow are nonlinear partial differential equations and are converted into ordinary differential equations via similarity transformations. These equations are then solved by the Finite Element Method. The effect of various important parameters on nondimensional velocity, temperature distribution, nanoparticle concentration, the density of motile micro-organisms is analyzed graphically in detail. It is observed from the obtained results that the flow velocity decreases with rising angle of inclination [Formula: see text] while temperature, nanoparticle’s concentration and density of motile micro-organisms increase. The local skin friction coefficient, Nusselt number, Sherwood number, motile micro-organism’s density number are calculated. It is noticed that increasing the Brownian motion and thermophoresis parameter leads to an increase in temperature of fluid which results in a reduction in Nusselt number. On the contrary, the Sherwood number rises with an increase in Brownian motion and thermophoresis parameter. Also, interesting features of the flow dynamics are elaborated and new future pathways for extension of the study identified in bio-magneto-nano polymers (BMNPs) for solar coatings.

scholarly journals Unsteady Flow of Reactive Viscous, Heat Generating/Absorbing Fluid with Soret and Variable Thermal Conductivity

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
I. J. Uwanta ◽  
M. M. Hamza
Keyword(s):  
Thermal Conductivity ◽  
Natural Convection ◽  
Skin Friction ◽  
Sherwood Number ◽  
Vertical Channel ◽  
Variable Thermal Conductivity ◽  
Finite Difference Schemes ◽  
Transfer Coefficients ◽  
Flow Parameters ◽  
Viscous Heat

This study investigates the unsteady natural convection and mass transfer flow of viscous reactive, heat generating/absorbing fluid in a vertical channel formed by two infinite parallel porous plates having temperature dependent thermal conductivity. The motion of the fluid is induced due to natural convection caused by the reactive property as well as the heat generating/absorbing nature of the fluid. The solutions for unsteady state temperature, concentration, and velocity fields are obtained using semi-implicit finite difference schemes. Perturbation techniques are used to get steady state expressions of velocity, concentration, temperature, skin friction, Nusselt number, and Sherwood number. The effects of various flow parameters such as suction/injection (γ), heat source/sinks (S), Soret number (Sr), variable thermal conductivityδ, Frank-Kamenetskii parameterλ, Prandtl number (Pr), and nondimensional timeton the dynamics are analyzed. The skin friction, heat transfer coefficients, and Sherwood number are graphically presented for a range of values of the said parameters.

Chemically Reacting MHD Mixed Convection Variable Viscosity Blasius Flow Embedded in a Porous Medium

2017 ◽  
Vol 374 ◽  
pp. 83-91 ◽  
Author(s):  
Oluwole Daniel Makinde ◽  
S.R. Mishra
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Nusselt Number ◽  
Mixed Convection ◽  
Skin Friction ◽  
Sherwood Number ◽  
Variable Viscosity ◽  
Fluid Viscosity ◽  
Reaction Heat ◽  
Blasius Flow

In this paper, the combined effects of magnetic field, buoyancy forces, nth order chemical reaction, heat source, viscous dissipation, Joule heating and variable viscosity on mixed convection Blasius flow of a conducting fluid over a convectively heated permeable plate embedded in a porous medium is investigated. The fluid properties are assumed to be constant except for the density variation with the temperature and reacting chemical species concentration. The nonlinear governing differential equations were obtained and solved numerically using the Runge-Kutta-Fehlberg method with shooting technique. The dimensionless velocity, temperature and concentration profiles are shown graphically. The effects of pertinent parameters on the skin friction, Nusselt number and Sherwood number are examined. It is found that skin friction decreases while Nusselt number and Sherwood number increase with a decrease in the fluid viscosity in the presence of magnetic field.

scholarly journals Computation of heat transfer of a plane turbulent jet impinging a moving plate

2014 ◽  
Vol 18 (4) ◽  
pp. 1259-1271 ◽  
Author(s):  
Dahbia Benmouhoub ◽  
Amina Mataoui
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Flow Field ◽  
Velocity Ratio ◽  
Local Heat Transfer ◽  
Slight Modification ◽  
Surface Velocity ◽  
Moving Plate ◽  
Jet Velocity

This study examines the performance of one point closure turbulence models in predicting of heat and momentum transfer of impinging flows. The scope of this paper is limited to impinging jet on a moving wall and heat transfer. The impinging distance is fixed to 8 thickness of the nozzle (8e) for this study. Two parameters are considered: the jet exit Reynolds number (10000?Re?25000) and the jet-surface velocity ratio (0?Rsj?4). the flow field structure at a given surface-to-jet velocity ratio is independent of the jet Reynolds number, a slight modification of the flow field is observed for low surface-to-jet velocity ratio (Rsj<0.25) whereas at higher ratios Rsj>0.25, the flow field is significantly modified. Good agreement with experimental results is obtained for surface-to-jet velocity ratio 0?Rsj?2. the purpose of this paper is to consider the case of higher of surface-to-jet velocity Rsj>2. A further study of heat transfer is achieved and shows that the stagnation points the local heat transfer coefficient have a maximum value. The local Nusselt number at the impinging region tends to decrease significantly when Rsj?1.5. The evolution of average Nusselt number is correlated according to the surface-to-jet velocity ratios for each Reynolds number.

Effect of Inlet Skew on Heat/Mass Transfer From a Simulated Turbine Blade

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Kalyanjit Ghosh ◽  
R. J. Goldstein
Keyword(s):  
Mass Transfer ◽  
Turbine Blade ◽  
Sherwood Number ◽  
Heat Mass Transfer ◽  
Velocity Ratio ◽  
Transition To Turbulence ◽  
Suction Surface ◽  
Freestream Velocity ◽  
Pressure Surface ◽  
Passage Vortex

Heat (mass) transfer experiments are conducted to study the effect of an inlet skew on a simulated gas-turbine blade placed in a linear cascade. The inlet skew simulates the relative motion between rotor and stator endwalls in a single turbine stage. The transverse motion of a belt, placed parallel to and upstream of the turbine cascade, generates the inlet skew. With the freestream velocity constant at approximately 16 m/s, which results in a Reynolds number (based on the blade chord length of 0.184 m) of 1.8 × 105, a parametric study was conducted for three belt-to-freestream velocity ratios. The distribution of the Sherwood number on the suction surface of the blade shows that the inlet skew intensifies the generation of the horseshoe vortex close to the endwall region. This is associated with the development of a stronger passage vortex for a higher velocity ratio, which causes an earlier transition to turbulence. Corresponding higher mass transfer coefficients are measured between the midheight of the blade and the endwall, at a midchord downstream location. However, a negligible variation in transport properties is measured above the two-dimensional region of the blade at the higher velocity ratios. In contrast, the inlet skew has a negligible effect on the distribution of the Sherwood number on the entire pressure surface of the blade. This is mainly because the skew is directed along the passage vortex, which is from the pressure surface of the airfoil to the suction surface of the adjacent airfoil.

Non-Newtonian Fluid Flow and Heat Transfer in a Semicircular Microtube Induced by Electroosmosis and Pressure Gradient

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Mehdi Karabi ◽  
Ali Jabari Moghadam
Keyword(s):  
Nusselt Number ◽  
Pressure Gradient ◽  
Flow Behavior ◽  
Velocity Ratio ◽  
Shear Thinning ◽  
Fluid Viscosity ◽  
Flow Behavior Index ◽  
Shear Thinning Fluids ◽  
Power Law Fluids ◽  
Behavior Index

The hydrodynamic and thermal characteristics of electroosmotic and pressure-driven flows of power-law fluids are examined in a semicircular microchannel under the constant wall heat flux condition. For sufficiently large values of the electrokinetic radius, the Debye length is thin; the active flow within the electric double layer (EDL) drags the rest of the liquid due to frictional forces arising from the fluid viscosity, and consequently a plug-like velocity profile is attained. The velocity ratio can affect the pure electrokinetic flow as well as the flow rate depending on the applied pressure gradient direction. Since the effective viscosity of shear-thinning fluids near the wall is quite small compared to the shear-thickening fluids, the former exhibits higher dimensionless velocities than the later close to the wall; the reverse is true at the middle section. Poiseuille number increases with increasing the flow behavior index and/or the electrokinetic radius. Due to the comparatively stronger axial advection and radial diffusion in shear-thinning fluids, better temperature uniformity is achieved in the channel. Reduction of Nusselt number continues as far as the fully developed region where it remains unchanged; as the electrokinetic radius tends to infinity, Nusselt number approaches a particular value (not depending on the flow behavior index).

The Production of Duct Velocity Profiles Having High Ratios of Maximum to Mean Velocity

1956 ◽  
Vol 60 (546) ◽  
pp. 415-417 ◽  
Author(s):  
J. L. Livesey ◽  
E. Parker ◽  
P. K. Jones
Keyword(s):  
Reynolds Number ◽  
Incompressible Flow ◽  
Pressure Loss ◽  
Velocity Ratio ◽  
Velocity Profiles ◽  
Mean Velocity ◽  
Entry Length ◽  
Loss Coefficients

The results are presented of an investigation of a particular type of baffle for the production of symmetrical velocity profiles having high ratios of maximum to mean velocity in ducted incompressible flow. Two similar families of profiles are obtained depending on whether a short (12 diameters) or a long (48 diameters) entry length is used before the baffle. The highest value of the maximum to mean velocity ratio obtained is 1·42 and the pressure loss coefficients associated with the use of the baffle are given together with an indication of the effect of Reynolds number.

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