scholarly journals Mixed Convection and Thermally Radiative Flow of MHD Williamson Nanofluid with Arrhenius Activation Energy and Cattaneo–Christov Heat-Mass Flux

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
S. Eswaramoorthi ◽  
Nazek Alessa ◽  
M. Sangeethavaanee ◽  
Safak Kayikci ◽  
Ngawang Namgyel
Keyword(s):  
Heat Transfer ◽  
Activation Energy ◽  
Mass Flux ◽  
Thermal Characteristics ◽  
Mhd Flow ◽  
Weissenberg Number ◽  
Fluid Temperature ◽  
Ode Models ◽  
Arrhenius Function ◽  
The Impact

In this paper, we explored the impact of thermally radiative MHD flow of Williamson nanofluid over a stretchy plate. The flow in a stretchy plate is saturated via Darcy–Forchheimer relation. Cattaneo–Christov heat-mass flux theory is adopted to frame the energy and nanoparticle concentration equations. Additionally, the mass transfer analysis is made by activation energy and binary chemical reaction. Activation energy is invoked through the modified Arrhenius function. The intention of the current investigation is to enhance the heat transfer rate in industrial processes. The non-Newtonian nanofluids have more prominent thermal characteristics compared to ordinary working fluids. The governing models are altered into ODE models, and these models are numerically solved by applying the MATLAB bvp4c algorithm. The graphical and tabular interpretations have scrutinized the impact of sundry distinct parameters. The fluid speed escalates for enhancing the Richardson number, and it falls off for higher values of the Weissenberg number. It is noticed that the fluid temperature declines for higher values of the Brownian motion parameter and it grows for larger values of the thermophoresis parameter. The activation energy enriches the heat transfer gradient and suppresses the local Sherwood number. Additionally, the more significant heat transfer gradient occurs in heat-absorbing nonradiative viscous nanofluid and a smaller heat transfer gradient occurs in heat-generating radiative Williamson nanofluid. Also, we noticed that a higher heat transfer gradient appears in the Fourier model than in the Catteneo–Christov model. In addition, the comparative results are confirmed and reached an outstanding accord.

Experimental Study of the Endwall Heat Transfer of a Transonic Nozzle Guide Vane With Upstream Jet Purge Cooling: Part 1 — Effect of Density Ratio

2020 ◽  
Author(s):  
Shuo Mao ◽  
Ridge A. Sibold ◽  
Stephen Lash ◽  
Wing F. Ng ◽  
Hongzhou Xu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Mass Flux ◽  
Guide Vane ◽  
Density Ratio ◽  
Momentum Ratio ◽  
Blowing Ratio ◽  
Nozzle Guide Vane ◽  
Nozzle Guide ◽  
The Impact

Abstract Nozzle guide vane platforms often employ complex cooling schemes to mitigate ever-increasing thermal loads on endwall. Understanding the impact of advanced cooling schemes amid the highly complex three-dimensional secondary flow is vital to engine efficiency and durability. This study analyzes and describes the effect of coolant to mainstream blowing ratio, momentum ratio and density ratio for a typical axisymmetric converging nozzle guide vane platform with an upstream doublet staggered, steep-injection, cylindrical hole jet purge cooling scheme. Nominal flow conditions were engine representative and as follows: Maexit = 0.85, Reexit/Cax = 1.5 × 106 and an inlet large-scale freestream turbulence intensity of 16%. Two blowing ratios were investigated, each corresponding to upper and lower engine extrema at M = 3.5 and 2.5, respectively. For each blowing ratio, the coolant to mainstream density ratio was varied between DR = 1.2, representing typical experimental neglect of coolant density, and DR = 1.95, representative of typical engine conditions. An optimal coolant momentum ratio between = 6.3 and 10.2 is identified for in-passage film effectiveness and net heat flux reduction, at which the coolant suppresses and overcomes secondary flows but imparts minimal turbulence and remains attached to endwall. Progression beyond this point leads to cooling effectiveness degradation and increased endwall heat flux. Endwall heat transfer does not scale well with one single parameter; increasing with increasing mass flux for the low density case but decreasing with increasing mass flux of high density coolant. From the results gathered, both coolant to mainstream density ratio and blowing ratio should be considered for accurate testing, analysis and prediction of purge jet cooling scheme performance.

Zero Mass Flux Effects on Time Dependent Flow of an Eyring Powell with Activation Energy

2020 ◽  
Vol 9 (3) ◽  
pp. 216-229
Author(s):  
Hussan Zeb ◽  
Hafiz Abdul Wahab ◽  
Umar Khan
Keyword(s):  
Activation Energy ◽  
Mass Flux ◽  
Slip Boundary Condition ◽  
Time Dependent ◽  
Physical Parameters ◽  
Detailed Result ◽  
Discussion Section ◽  
Nonlinear Odes ◽  
Zero Mass ◽  
The Impact

In this work we demonstrated the impacts of zero mass flux in Powell-Eyring fluid over time dependent stretching sheet. We analyzed the Arrhenius activation energy in heat transfer with momentum and thermal slip boundary condition. The governing model is very complex to solve it directly therefore we transform these governed model into a coupled nonlinear ODEs via similarity transformation. After that, we solve these ODEs by using numerica method so calledshooting technique with RK-technique. The characteristics of different beneficial physical parameters on momentum, energy and concentration fields are represented through graphs. We concluded in this work the arising or reducing in the velocity, temperature and concentration fields for the existence of physical parameters. The impact of physical quantities namely skin fraction (Cf), Nusselt (Nux) and Sherwood (Shx) numbers are calculated numerically via tables. In this paper we concluded that the decreases occurring in velocity field for higher values of (M) (H) and (β). Moreover the characteristics of concentration Φ(ζ), temperature θ(ζ) and velocity f′(ζ) gradients are presented for important physical parameters see in detailed Result and discussion section.

Enhanced Heat Transfer in Moderately Ionized Liquid Due to Hybrid MoS2/SiO2 Nanofluids Exposed by Nonlinear Radiation: Stability Analysis

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 142 ◽  
Author(s):  
Umair Khan ◽  
A. Zaib ◽  
Ilyas Khan ◽  
Dumitru Baleanu ◽  
Kottakkaran Sooppy Nisar
Keyword(s):  
Heat Transfer ◽  
Ethylene Glycol ◽  
Silicon Oxide ◽  
Strain Tensor ◽  
Boundary Layer Separation ◽  
Radiation Stability ◽  
Weissenberg Number ◽  
Nonlinear Radiation ◽  
Reliable Solution ◽  
The Impact

This study considers ethylene-glycol as a moderate ionized regular liquid whose rheological behavior can be analyzed through the relations of the Carreau stress–strain tensor. Hybrid nanoliquids are potent liquids that give better performance for heat transfer and the properties of thermo physical than regular heat transfer liquids (water, ethylene glycol, and oil) and nanoliquids by single nanomaterials. Here, a type of hybrid nanoliquid involving silicon oxide (SiO2) and Molybdenum disulfide (MoS2) nanoparticles with ethylene glycol as a base liquid are considered. In addition, the impact of nonlinear radiation along with Lorentz force is invoked. Similarity variables are utilized to acquire the numerical findings and their solutions for transmuting ordinary differential equations (ODEs). Using bvp4c from MATLAB, we can obtain these quantitative and numerical results of the converted nonlinear equations. The impacts of the pertinent constraints on the temperature distribution, velocity, Nusselt number, and skin friction are estimated. The outcomes indicate that the double-edged methods for the results originate from the precise values of the permeable parameters. Further, the critical values (Sc = 1.9699, 2.0700 and 2.2370) are enhanced due to the influence of the local Weissenberg number. This implies that the increasing value of the local Weissenberg number accelerate the boundary layer separation. Furthermore, a stability investigation is performed and confirms that the first solution is a physically reliable solution.

HEAT GENERATION AND ABSORPTION IN MHD FLOW OF CASSON FLUID PAST A STRETCHING WEDGE WITH VISCOUS DISSIPATION AND NEWTONIAN HEATING

2018 ◽  
Vol 80 (3) ◽  
Author(s):  
Imran Ullah ◽  
Sharidan Shafie ◽  
Ilyas Khan
Keyword(s):  
Heat Transfer ◽  
Skin Friction ◽  
Heat Transfer Rate ◽  
Heat Generation ◽  
Transfer Rate ◽  
Fluid Velocity ◽  
Mhd Flow ◽  
Casson Fluid ◽  
Skin Friction Coefficient ◽  
Fluid Temperature

The dissipative flow of Casson fluid in the presence of heat generation and absorption is investigated. The flow is induced due to stretching wedge. The similarity transformations were used to to transformed the governing equations into ordinary differential equations. The transformed equations are solved numerically via Keller-box method. Numerical results for skin friction coefficient are compared and found in excellent agreement with published results. The effects of pertinent parameters on velocity and temperature profiles as well as skin friction and heat transfer rate are graphically displayed and analyzed. It is noticed that fluid velocity drops with the increase of Casson fluid and magnetic parameters when the wedge is stretching faster than free stream. It is also noted that the heat transfer rate at wedge surface reduces with the increase of Eckert number, whereas the reverse trend is noted in the case of Casson and radiation parameters. Moreover, with increasing of heat generation or absorption parameter the fluid temperature rises.

scholarly journals Numerical simulation for bioconvectional flow of burger nanofluid with effects of activation energy and exponential heat source/sink over an inclined wall under the swimming microorganisms

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hassan Waqas ◽  
Umar Farooq ◽  
Aqsa Ibrahim ◽  
M. Kamran Alam ◽  
Zahir Shah ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Activation Energy ◽  
Differential Equations ◽  
Heat Source ◽  
Lewis Number ◽  
Numerical Results ◽  
Solid Particles ◽  
Liquid Component ◽  
Pharmaceutical Industries ◽  
The Impact

AbstractNanofluids has broad applications such as emulsions, nuclear fuel slurries, molten plastics, extrusion of polymeric fluids, food stuffs, personal care products, shampoos, pharmaceutical industries, soaps, condensed milk, molten plastics. A nanofluid is a combination of a normal liquid component and tiny-solid particles, in which the nanomaterials are immersed in the liquid. The dispersion of solid particles into yet another host fluid will extremely increase the heat capacity of the nanoliquid, and an increase of heat efficiency can play a significant role in boosting the rate of heat transfer of the host liquid. The current article discloses the impact of Arrhenius activation energy in the bioconvective flow of Burger nanofluid by an inclined wall. The heat transfer mechanism of Burger nanofluid is analyzed through the nonlinear thermal radiation effect. The Brownian dispersion and thermophoresis diffusions effects are also scrutinized. A system of partial differential equations are converted into ordinary differential equation ODEs by using similarity transformation. The multi order ordinary differential equations are reduced to first order differential equations by applying well known shooting algorithm then numerical results of ordinary equations are computed with the help of bvp4c built-in function Matlab. Trends with significant parameters via the flow of fluid, thermal, and solutal fields of species and the area of microorganisms are controlled. The numerical results for the current analysis are seen in the tables. The temperature distribution increases by rising the temperature ratio parameter while diminishes for a higher magnitude of Prandtl number. Furthermore temperature-dependent heat source parameter increases the temperature of fluid. Concentration of nanoparticles is an decreasing function of Lewis number. The microorganisms profile decay by an augmentation in the approximation of both parameter Peclet number and bioconvection Lewis number.

scholarly journals Stefan Blowing Impacts on Unsteady MHD Flow of Nanofluid over a Stretching Sheet with Electric Field, Thermal Radiation and Activation Energy

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1048
Author(s):  
Syed Muhammad Ali Haider ◽  
Bagh Ali ◽  
Qiuwang Wang ◽  
Cunlu Zhao
Keyword(s):  
Activation Energy ◽  
Thermal Radiation ◽  
Electric Fields ◽  
Chemical Reaction ◽  
Stretching Sheet ◽  
Flow Characteristics ◽  
Mhd Flow ◽  
Temperature Fields ◽  
Nanoparticle Concentration ◽  
The Impact

In this paper, a mathematical model is established to examine the impacts of Stefan blowing on the unsteady magnetohydrodynamic (MHD) flow of an electrically conducting nanofluid over a stretching sheet in the existence of thermal radiation, Arrhenius activation energy and chemical reaction. It is proposed to use the Buongiorno nanofluid model to synchronize the effects of magnetic and electric fields on the velocity and temperature fields to enhance the thermal conductivity. We utilized suitable transformation to simplify the governing partial differential equation (PDEs) into a set of nonlinear ordinary differential equations (ODEs). The obtained equations were solved numerically with the help of the Runge–Kutta 4th order using the shooting technique in a MATLAB environment. The impact of the developing flow parameters on the flow characteristics is analyzed appropriately through graphs and tables. The velocity, temperature, and nanoparticle concentration profiles decrease for various values of involved parameters, such as hydrodynamic slip, thermal slip and solutal slip. The nanoparticle concentration profile declines in the manifestation of the chemical reaction rate, whereas a reverse demeanor is noted for the activation energy. The validation was conducted using earlier works published in the literature, and the results were found to be incredibly consistent.

Study on the Frequency Response Characteristics of Thermal Stress Induced by Multidimensional Fluid Temperature Fluctuation

2012 ◽  
Author(s):  
Cristian Santiago Perez T. ◽  
Naoto Kasahara
Keyword(s):  
Heat Transfer ◽  
Thermal Stress ◽  
Frequency Response ◽  
Temperature Fluctuation ◽  
Hot Spot ◽  
Heat Diffusion ◽  
Fluid Temperature ◽  
Dimensional Approach ◽  
One Dimensional ◽  
The Impact

A simplified one dimensional approach for predicting the thermal stress in structures subject to near wall fluid temperature fluctuations has been previously developed and published by the author Kasahara. The method predicted the thermal stress by calculating the frequency response, formulated by the product of the effective heat transfer and the effective thermal stress related to one-dimensional temperature gradient developed through the wall thickness of the structure. Although, currently adopted by the Japanese Society of Mechanical Engineers (JSME) guideline for calculating the thermal fatigue damage in structures, recent studies have highlighted the limitations of the one dimensional approach by showing the presences of multidimensional fluid temperature fluctuation in plane direction, increasing the need to extend the current analysis to more detailed multidimensional guideline. The aim of this research is to advance the theoretical knowledge and understanding of complex multidimensional phenomenon related to local thermal fluctuations within small localized area at the surface of the structure, referred to as “Hot Spot” which is observed to have important effects on the thermal stress phenomenon. Furthermore, the understanding of heat transfer processes in the structure, especially heat diffusion that is known to produce a thermal gradient and, therefore, thermal stress. Understanding the behavior of each heat transfer process in the Hot Spot and the relationship to the response in frequency has formed the bases for extending the current one-dimensional model. This paper presents the analytical results of the study and proposes an extended multidimensional model to understand the thermal stress in tee-junction due to fluid temperature fluctuation and the close relation with the frequency. The model is derived from the understanding of the phenomenon which has leaded to quantify the effect by introducing certain multidimensional factors to explain the impact of the multidimensional fluid temperature fluctuation.

Parametric Study of a Transient Liquid Flow in a Microchannel of Square Cross-Section

2010 ◽  
Author(s):  
Guyh Dituba Ngoma ◽  
Amsini Sadiki
Keyword(s):  
Heat Transfer ◽  
Cross Section ◽  
Liquid Flow ◽  
Thermophysical Properties ◽  
Electric Potential ◽  
Thermal Characteristics ◽  
Temperature Fields ◽  
Transfer Coefficients ◽  
The Impact ◽  
Potential Pressure

Time-dependent laminar liquid flow and thermal characteristics in a square cross-section microchannel were numerically investigated using computational fluid dynamics code. In the numerical model developed the upper and bottom microchannel substrate properties, Joule heating caused by applying electric potential, pressure driven flow, electroosmosis, heat transfer coefficients on the microchannel bottom wall and variations in the liquid thermophysical properties were all taken into account. Liquid flow velocity distribution and temperature fields were calculated by solving both Navier-Stokes and energy equations, and electric field distribution was determined based on their electric potential. The results obtained demonstrate the impact that applied potential, pressure difference, heat transfer coefficient and microchannel dimensions have on liquid flow and thermal behaviors in a square microchannel. Finally, the results with the model developed were then compared with those of a liquid having constant thermophysical properties.

scholarly journals Finite Element Analysis of Variable Viscosity Impact on MHD Flow and Heat Transfer of Nanofluid Using the Cattaneo–Christov Model

Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 395 ◽  
Author(s):  
Liaqat Ali ◽  
Xiaomin Liu ◽  
Bagh Ali
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Finite Element ◽  
Differential Equations ◽  
Thermal Relaxation ◽  
Fluid Temperature ◽  
Flow And Heat Transfer ◽  
Flux Model ◽  
The Impact ◽  
Heat Flux Model

In this mathematical study, magnetohydrodynamic, time-independent nanofluid flow over a stretching sheet by using the Cattaneo–Christov heat flux model is inspected. The impact of the thermal, solutal boundary and gravitational body forces with the effect of double stratification on the mass flow and heat transfer phenomena is also observed. The temperature-dependent viscosity impact on heat transfer through a moving sheet with capricious heat generation in nanofluids have studied, and the viscosity of the fluid is presumed to deviate as the inverse function of temperature. With the appropriate transformations, the system of partial differential equations is transformed into a system of nonlinear ordinary differential equations. By applying the variational finite element method, the transformed system of equations is solved. The properties of the several parameters for buoyancy, velocity, temperature, stratification, and Brownian motion parameters have examined. The enhancement in the concentration and thermal boundary layer thickness of the nanofluid sheet due to the increment in the viscosity parameter, also increased the temperature and concentration of nanoparticles. Moreover, the fluid temperature declined with the increasing values of thermal relaxation parameter. This displays that the Cattaneo–Christov heat flux model provides a better assessment of temperature distribution. Moreover, confirmation of the code and precision of the numerical method has inveterate with the valuation of the presented results with previous studies.

Significance of Arrhenius activation energy in flow and heat transfer of tangent hyperbolic fluid with zero mass flux condition

2020 ◽  
Vol 26 (8) ◽  
pp. 2517-2526 ◽  
Author(s):  
K. Ganesh Kumar ◽  
Abeer Baslem ◽  
B. C. Prasannakumara ◽  
Jihen Majdoubi ◽  
Mohammad Rahimi-Gorji ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Activation Energy ◽  
Mass Flux ◽  
Arrhenius Activation Energy ◽  
Zero Mass ◽  
Flow And Heat Transfer ◽  
Flux Condition ◽  
Tangent Hyperbolic Fluid
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