Effects Of Buoyancy Forces Research Articles

An experimental investigation of the flow characteristics and heat transfer properties of a heated and an unheated vertically positioned circular cylinder at different Reynolds numbers

This study investigated flow characteristics and heat transfer properties simultaneously around a heated circular cylinder vertically immersed in a water channel at different Reynolds (Re) numbers. The channel water temperature and heat flow were kept constant during the experiments. The results included time-averaged vorticity contours (<ω>), streamlines (<Ѱ>), turbulent kinetic energy (<TKE>), the root mean square value of the velocity component in the streamwise direction 〈Urms〉, and the root mean square value of the spanwise velocity component 〈Vrms〉. Thermal buoyancy forces disrupt the periodic vortex formation around the cylinder. Depending on the increased Richardson number, the dead flow zone grew significantly smaller and was eliminated at the value of Re=500 in such a way that it prevented flow separation. In the unheated condition, however, a higher turbulent kinetic energy (TKE) emerged around the junction in the wake region. In contrast, a high TKE was formed in the region closer to the cylinder wall with the cylinder being heated. At the Reynolds number of 5000, the effects of thermal buoyancy forces on the flow properties in the wake of the heated cylinder were found to be negligible. Even though the effects of the oscillations caused by thermal buoyancy forces persisted on the vortex formation due to the increased Reynolds number, the oscillation amplitudes significantly declined. It was noted that, at lower Reynolds numbers (especially Re=500, Re=1000, and Re=1500), the difference between the Nusselt (Nu) distribution around the cylinder was small and that the Nu distribution tended to form almost a straight line as a result of the increased thermal boundary layer thickness. The difference between the maximum and minimum Nusselt values around the cylinder increased directly to the rise in the Reynolds number. It, therefore, appeared that the higher the Reynolds numbers, the more the turbulence in such a way as to improve the heat transfer.

Experimental investigation on convective heat transfer of hydrocarbon fuel in transverse corrugated tubes

To improve the heat transfer performance of regenerative fuel cooling technology and CCA (Cooled Cooling Air) technology, the convective heat transfer characteristics of hydrocarbon fuel in transverse corrugated tubes under supercritical pressures were experimentally studied. The length, outer and inner diameter of the test tubes were 200 mm, 3 mm, and 2 mm, respectively, and the corrugation depth was 0.4 mm. The corrugation pitches of different transverse corrugated tubes were 30, 40, and 50 mm, respectively. The effects of heat flux, system pressure, mass flow rate, inlet temperature, buoyancy, and corrugation pitch are summarized. Experimental results indicated that the secondary flow and backflow are generated behind the concave corrugation, which can destroy the fluid boundary layer, make the fluid mixing more uniform, reduce the temperature gradient of the boundary layer, and enhance heat transfer. An average HTC (heat transfer coefficient) was increased by 35–51% compared with the plain tube. In addition, a ratio of Gr (Grashof number) to the square of Re (Reynolds number) was used as the criterion for evaluating the effect of buoyancy force. Gr⋅Re−2 near the corrugation was much smaller than in other locations.

The influence of material on the power performance of Savonius turbines in wind and water applications

Savonius turbines are practical for rivers with low speeds due to their simple design and good self-starting capabilities. Despite these advantages, real implementation is still limited due to their low power efficiency. However, the experimental studies are scarce as they mainly focus on power performance, neglecting the impact of materials exposed to the wind or water medium. Therefore, the current study aims to address this gap by investigating the influence of materials on the power performance of Savonius turbines in wind and water, particularly the effect of their mass moment of inertia (I). Aluminum (ALU) and Polylactic Acid (PLA) were selected as the materials for the turbines as they are the typical materials frequently used to fabricate the turbines. They were tested experimentally in a wind tunnel and a water flume with Reynolds numbers ranging from 52, 000 to 83, 600. The findings discovered that although the turbine materials have the exact mass moments of inertia, they perform differently in water and wind. The turbines exhibit higher power coefficient with increasing mass moment of inertia in the wind at low Reynolds numbers (Re < 70,000), which is most likely due to reduced bearing friction that is more pronounced in the low Reynolds number region. The power coefficient was more likely to be affected in the wind than in water due to the effect of water buoyancy force, which reduces the influence of the increased mass moment of inertia. The results also revealed that the ALU and PLA with the same overall mass moment of inertia had maximum power coefficients of 11% and 18% in wind and water, respectively. There is no significant difference in terms of self-starting speed due to the variation in the moment of inertia. The Reynolds number and the turbine starting angle appeared to have a greater effect on self-starting capabilities than the moment of inertia. The findings of this study help to establish the types of materials that are optimal for enhancing the turbine performance in wind or water applications and could potentially save a lot of costs in generating power.

Significance of porous elliptical cylinder on the MHD natural convection

In this analysis, the significance of different alignments of porous elliptical cylinder and orientation of magnetic field intensity on the buoyancy driven flow and heat transfer traits in an enclosure is investigated through lattice Boltzmann technique. Various amalgamations of the orientations of curved porous cylinder and magnetic field are carried out for the first time, which is essential in real-time applications like compact electronic devices, nuclear reactor cooling, and heat exchangers. The classical outcome of the individual parameters considered in the study can be altered through different combinations, and this information serves for the favourable heat transfer performance. This parametric study focuses on the effects of buoyancy force (Ra=104, 105, &106), non-dimensional permeability (Da=10−5, 10−4, &10−3), magnetic field intensity (Ha=0, 25, & 50), magnetic field orientation (γM=0°, 45°, &90°), and orientation of the porous elliptical cylinder (Case-1=0°, Case-2=30°, Case-3=45°, &Case-4=90°) on the hydro-thermal behaviour in and around the porous cylinder. The Darcy–Brinkman–Forchheimer equation is linked with the LB flow evolution equation to obtain the flow features of porous medium. It is observed that the flow-field intensity in and around the porous zone is directly proportional the imposed buoyancy force and permeability. Unsteady traits in flow and thermal fields are seen at higher Ra and Da when the porous body is not streamlined. The amount of fluid penetration and the distance travelled by it in the porous zone are the deciding factors for the heat transfer variation of different orientations of the porous cylinder. The sway of buoyancy force on the heat transfer intensification is hampered by the intensity of magnetic field. In the case of Θ=0° the % increment in mean Nusselt number (NuM) at Ra=105 with respect to Ra=104 is 108.2%, 66.6%, & 18.2% for Ha=0, 25, & 50, respectively. Although, magnetic field has displayed adverse influence on the thermal performance, by tuning the orientation of the magnetic force, the heat transfer can be significantly improved (about 9.3% increment when γM=90°, Ra=106&Da=10−3). The impact of magnetic field and its orientation are found to be significant when the buoyancy force and permeability are more. At lower permeabilities of the cylinder, the streamlined shape offered higher heat transfer rate, whereas, at higher permeabilities such pattern reverses. Besides, it is seen that few amalgamations of parameters embraced in the study offered a drastic variation in flow and heat transfer behaviour.

Study of entropy generation and heat flow through a microtube induced by the membrane-based thermofluidics systems

A mathematical model to study the thermally fully developed pressure-driven flow of Newtonian fluid in a finite length vertical microtube with a spatial–temporal dependent membrane contraction, is presented. Here, pressure is generated by the membrane propagation and is further regulated by buoyancy forces. Besides, the energy equation refers to the movement of thermal energy between two walls of the microtube. This model examines the kinematics of membrane, flow and pumping characteristics, wall shear stress, Grashof number (Buoyancy force) effects, Nusselt number, isotherms, and entropy generation in the membrane based thermofluidics system. The dimensional analysis followed by the lubrication approach (since radius of the microtube is substantially less than its length) has been utilized to derive the analytical solutions which are further simulated by using the Matlab code for the graphical illustrations. The velocity fields under the effects of thermal properties and membrane kinematics are computed and noted that magnitude to axial velocity increases by 44.8% via the Grashof number in the range 0 to 4. Further, it is observed that the convective heat flow ( N u > 1 ) is performing in the range [ − 0 . 2 , 0 . 2 ] due to the rhythmic membrane kinematics. Another side, the membrane shape parameter is a major concern for the entropy generation. Such types of analysis and membrane based thermofluidics could be applicable to control the heat transfer rate and energy in various thermal treatments of biomedical sciences and engineering, and also help to design the thermo-pneumatic micropump. • A mathematical model for heat transfer in membrane based microtube is presented. • The membrane pumping mechanism is highly motivated by insect’s respiratory system. • The direct heat source increases the temperature elevation up to 49% in microtube. • Entropy can be controlled by relative temperature and membrane shape in the system. • The findings of the present model are useful in various thermal treatments.

Numerical study on transient airflows and air exchange induced by door motion in thermally stratified environment

Door motion has been identified as a contribution factor for containment transport between indoor and outdoor, but the combined airflow characteristics due to door motion, ventilation airflow and thermal effects have not been clarified. This paper investigated transient airflow characteristics and amount of air exchange induced by hinged door motions in thermally stratified environment with displacement ventilation using dynamic CFD simulation. The results show that about 40% amount of air exchange occurs in the first phase when door angle β < 30° although the consumed time is only 15% of the whole door motion process. Indoor and outdoor air temperature difference and rotation speed of the hinged door are two important influencing factors. When the door motion is slow enough and temperature difference is above 3 °C, the thermal convective flow could significantly affect the airflow pattern through the doorway. When there is no indoor and outdoor temperature difference, the amount of air exchange increases linearly with door motion speed. Under combined effects of buoyancy force and door motion, a moderate door speed results in minimum air exchange. The door motion only affects the air temperatures near the door. The overall thermal stratification in the displacement ventilated room is not significantly destroyed by a single door open and close cycle. The findings could provide suggestions for reducing door motion induced contaminant transport, and enhance understanding of dynamic disturbance effects in thermally stratified environments.

Significance of bio-convection, MHD, thermal radiation and activation energy across Prandtl nanofluid flow: A case of stretching cylinder

The current research investigates the effects of Brownian motion, thermophoresis, and multi buoyancy forces on MHD Prandtl fluid as it flows through a stretched cylinder with convective boundary conditions. Linear thermal conductivity is included in the energy equation's development. The nanofluid flows are important in cooling systems, modern nano-technology, electronic parts and heat exchangers. The primary objective of this research is to enhance heat transportation. The problem consists of nonlinear PDEs and these equations are transformed into ODEs by incorporating suitable similarity transformations. The shooting strategy is used to solve the problem numerically after converting the non-dimensional ordinary differential equations to a system of first-order ODEs. A comparison is made between the MATLAB-generated findings and those that have already been published. The numerical results of various parameters have been systematically organized into tabular representations. Graphs show how significant parameters affect the given velocity, temperature, concentration, and motile microorganism measurements. When the buoyancy ratio and bio-convective Rayleigh number increase, the velocity profile drops; however, the temperature profile shows increasing behavior for the thermal radiation parameter. The concentration profiles are enhanced for the higher inputs in curvature parameter, magnetic parameter, and activation parameter while the density of motile microbes' decay for enhanced inputs of bio-convective Lewis number.

Numerical analysis of evaporation from a falling film in a vertical parallel plate channel

A detailed numerical analysis is performed of evaporation from a laminar falling liquid film with a co-current laminar gas-vapour mixture flow in a vertical parallel plate channel. A finite volume method is used to obtain a fully coupled implicit solution of a complete set of parabolic two-phase two-dimensional governing equations. Comparisons with the previous numerical and experimental studies are made to demonstrate the accuracy and capability of the present numerical model. Water-air and ethanol-air mixtures are used to examine the effects of buoyancy forces on the flow and the thermal characteristics of the evaporation process. The effects on the heat and mass transfer of the system of the wall heat flux, the relative humidity, and the inlet pressure are investigated.

The combined effect of coriolis and centrifugal buoyancy forces on internal cooling of turbine blades with modified ribs using Large Eddy Simulation (LES)

Cooling of turbine blades is necessary for longer durability and better thermal efficiency of the turbines. Turbine blade cooling is fulfilled by passing a coolant through the serpentine channel roughened with turbulators. In this work, the combined effect of the centrifugal buoyancy and the Coriolis force on heat transfer of a square duct roughened with ribs is studied using Large Eddy Simulation (LES). Simulations are carried for a Reynolds number based on bulk velocity of 20,000 with staggered square (SQ) rib, Backward step (BS) rib, and Forward step (FS) rib on the leading and trailing wall. The heat transfer performance of the square duct roughened with ribs is compared at rotation numbers Ro=0.35,0.67 and Richardson numbers Ri=0.0,12.0,28.0. The heat transfer augmentation for SQ-, BS-, and FS-ribs for Ro=0.67 and Ri=28 is 4.2%, 8.6% and 14.9%, respectively, higher than that without the effects of buoyancy. The friction coefficient for SQ-, BS-, and FS-ribs for Ro=0.67 and Ri=28 is 12.8%, 14.8% and 13.3% respectively higher than that without buoyancy.

Computational investigation on heat transfer of supercritical CO2 in horizontal U-tubes

The convective heat transfer characteristics of sCO2 in a horizontal U-tube are numerically investigated in this work. Considering the special geometry design of U-tube and the great variation of the supercritical fluid (SCF) properties, the reliability of four turbulence models is verified. Effects of operation parameters, buoyancy, flow acceleration and centrifugal force on the heat transfer characteristics are further investigated. Results show that, the position where the Tb is close to the Tpc has an important influence on the heat transfer. Centrifugal force mainly enhances the heat transfer coefficient (HTC) in the U-section and the outlet-section, and restrains the buoyancy and flow acceleration effect. The competition between buoyancy and centrifugal force leads to the enhancement of secondary flow and heat transfer. Finally, new heat transfer correlations which can be used in U-section and outlet-section are proposed in this paper.

Numerical study on heat transfer characteristics of supercritical CO2 in a vertical heating serpentine micro-tube

Supercritical CO2 heat exchangers are used in many industries. In some applications, the channel may not be straight, but rather serpentine. The effects of mass flux (G = 100–200 kg/m2s) and heat flux (qw = 30–90 kW/m2) on the heat transfer of a vertical serpentine micro-tube (d = 1 mm) and the different effects of buoyancy and centrifugal force on the flow and heat transfer of a vertical serpentine micro-tube in the liquid-like region and the gas-like region are studied by numerical simulation. Under the same operating conditions, the heat transfer coefficient decreases with the increase of heat flux and increases with the increase of mass flux. The liquid-like region is greatly affected by buoyancy, resulting in the heat transfer coefficient of upward flow is significantly lower than that of downward flow, and the heat transfer coefficient fluctuates violently. The gas-like region is less affected by buoyancy, resulting in small difference between upward flow and downward flow heat transfer coefficients, and the heat transfer coefficient fluctuates less. At the turning point of the serpentine micro-tube, the centrifugal force mutation results in the weakened heat transfer of the local tube wall, and the weakened layer in the liquid-like region is larger than that in the gas-like region. These findings are important for understanding the effects of buoyancy and centrifugal force on flow and heat transfer in the liquid-like region and the gas-like region.

Analysis of supercritical heat transfer in horizontal helical tube with internal roughness

• Supercritical flow in horizontal helical tube with internal roughness is analyzed. • Circumferential non-uniformity and axial oscillation of T w are explored. • The internally ribbed roughness and concaved roughness are compared. • The effects of spiral roughness, centrifugal force, and buoyancy are revealed. Helically coiled tube with smooth wall (HSW) has been widely used in the fields of supercritical air conditioning systems and supercritical heat pump systems due to its compact structure and excellent heat transfer performance. However, its large circumferential non-uniformity and intense axial oscillation will bring to local stress concentration and instability of heat transfer which are both responsible for system accidents. To alleviate the above two crises, the spiral inner wall roughness is proposed to be introduced into HSW. Up to now, the performance of helically coiled tube with internally ribbed roughness (HRW) has been seldom reported and the effectivenesses of inner roughness with different structures on suppressing circumferential non-uniformity and axial oscillation are still unclear. In this work, the SST k - ω model is employed to simulate the turbulent flow of s-R1234ze(E) in horizontal HRW to fill these gaps. Firstly, the effectivenesses of different rib heights, rib lift angles, rib widths, rib numbers, and rib base angles on restraining circumferential non-uniformity and axial oscillation are explored. The influences of wall thickness are also contained. Subsequently, the internally ribbed roughness and concaved roughness are compared and evaluated according to the overall comprehensive performance criterion. Finally, the effects of spiral roughness, centrifugal force, and gravitational buoyancy force on the flow field distributions are also revealed.

Calculation of spatial and temporal distributions of temperature and velocity of a weld pool during laser welding

The laser welding process is one of the most widely used processes in the industry. The study of the distributions of temperature and fluid velocity in the weld pool plays an important role in determining the size and shape of the weld. In this paper, we are interested in the numerical study of the welding phenomenon in the weld pool resulting from the interaction of a laser beam with a magnesium alloy (AZ91). We use the equation of energy, the equations of conservation of movement, the equation of continuity, and the equation of phase transition energy; we take into account the effect of Marangoni and buoyancy force. For the numerical model, we use the Finite Volume Method (FVM) and Gauss-Seidel iterative method. We calculate spatial and temporal distributions of temperature and fluid velocity in a cylindrical coordinates system (r, θ, z). We study how laser Power and welding speed affect the width and the depth of the weld pool. The results of this numerical model are compared with an experimental study.

Numerical analysis of MHD nanofluid flow and heat transfer in a circular porous medium containing a Cassini oval under the influence of the Lorentz and buoyancy forces

AbstractThis paper reports our study on the flow characteristics and heat transfer performance of magnetohydrodynamics (MHD) nanofluid in an innovative porous, circle‐shaped enclosure incorporating a Cassini oval cavity using the Darcy law. The MHD nanofluid considered in this study is Al2O3–H2O. A two‐dimensional (2D) mathematical model is developed based on a homogeneous model. The formulation of the vorticity stream function is then used to obtain coupled equations. Finally, the coupled partial differential equations are solved numerically using the finite element method. Model predictions are then compared against results from the previously published study to verify the accuracy and validity of the developed model, and a good agreement is achieved. Figures demonstrate the effects of nanoparticle volume fraction, inclined angle, Lorentz, and buoyancy forces on the MHD nanofluid flow. The results indicate that the convection mechanism becomes weaker with an increase in solid nanoparticle volume fraction. A significant increase in the Rayleigh number will lead to a stronger and more cohesive core vortex. In addition, when magnetic force is applied horizontally, favorable Nuave occurs. Based on the numerical results, a correlation to predict the average Nusselt number within the enclosure is developed as a function of Hartmann number (Ha), Rayleigh number (Ra), and inclined angle (γ).

Investigation of convection and radiation heat transfer of paraffinic materials and storage of thermal energy in melting process of PCMs in the cavity with transparent inner walls

Phase change materials have wide applications as thermal energy storage systems. Due to the low thermal conductivity of these materials, lots of efforts have been made to increase the thermal conductivity and efficiency of thermal energy storage systems. In this numerical study, convective and radiation heat transfer on a cavity with transparent inner walls have been investigated considering the effects of buoyancy force and viscosity of phase change materials. For this purpose, computational fluid dynamics that have high accuracy in calculations have been used. The considered wall is made of brick, in which the cavity containing phase change materials is included and layers of cement and plaster are placed on the wall. The results indicate that increasing the heat flux increases the effects of convective heat transfer. In addition, by applying radiation effects, the melting process of paraffin materials increases by 31%. Due to the transparency of the inner walls of the cavity, the radiation process occurred surface to surface. Therefore, with increasing amount of molten material, the radiation effects increase, the reason for this is that RT24 material is more transparent in liquid form than solid material. Also, increasing the heat flux from 50 to 100 and 300 (w/m2) increases the speed of the melting process by 19.3% and 27.2%, respectively.

Numerical Study Mixed Convection in a Channel with an Open Cavity Involving Rotary Cylinder

A numerical study of mixed convection inside a horizontal channel with an open square cavity that includes an adiabatic rotating cylinder. The bottom wall of the cavity is heated at a constant temperature, and the remaining walls are adiabatic. The flow is incompressible, laminar and steady state. The equations of continuity, momentum and energy are solved numerically using computational fluid dynamics (CFD) with the commercial software package FLUENT 2019 R1. Reynolds number values of 50, 100 and 150, the Richardson number (0.1 ≤ Ri ≤ 10) and the angular velocity (ω) of cylinder is (0.5 ≤ ω ≤ 4) rad/sec with direction counter clockwise. Prandtl number for air flow is (Pr = 0.7). The results are presented in terms of streamlines, isotherms, and the average Nusselt value is given over the heated bottom cavity. The combined effects of natural and forced convection in and out of the cavity were obtained. The results showed that at low Richardson values, Ri = 0.1 the effect of buoyancy force is neglected. The effect of increasing the cylinder speed is clearly noticeable at low Reynolds values, Re = 50. Average Nusselt values increase with increasing rotational speed of the cylinder for all Richardson values.

Numerical simulation for energy consumption and thermal comfort in a naturally ventilated indoor environment under different orientations of inlet diffuser

This study numerically analyses a well-validated comprehensive work on IEQ in a naturally ventilated, occupied 3-dimensional office building with installed furniture and internal heat-generating surfaces. This study analyzes the effect of the inlet diffuser orientation (IDO) on the indoor thermal comfort (ITC) of occupants and the energy demand of the building for heating indoor air. The Optimization of ITC has also been calculated for the acceptable indoor occupant comfort and energy consumption. The study is valuable to analyze the relationship between IDO of 0°, 15°, 30°, 45°, 60°and 75°, on ITC and the energy consumption of the indoor environment. Different methods have been chosen to study the ITC of the occupants such as air temperature, air movement in the occupied zone, vertical temperature gradient, and PMV and PPD index according to ISO7730. The results show that under a uniform indoor air distribution, the variation in IDO considerably affects the ITC and energy consumption. Optimized ITC can reduce indoor energy consumption by 35.14%. The IDO slightly affects the PMV and PPD index. Occupant's legs are more sensitive to the naturally ventilated indoor environment due to the adverse effect of buoyancy force which may create the problem of the cold draft. For optimization of the ITC, the air temperature in the occupied zone plays a key role.

Comparison of volume measurements of mass standards at low pressures and in liquids

The determination of the volumes of mass standards is key to the precise determination of their masses, due to the effect of the air buoyancy force. The buoyancy force can either be reduced by mass determination at low pressure or enlarged for a determination of the apparent mass using a vessel filled with liquid. The standard method for the volume calibration of weights is comparison in liquid, as described in the document OIML R111. This report presents the results of calibrating the volumes of stainless-steel mass standards with a nominal mass of 1 kg at low pressure and in a liquid. The authors showed that both methods produced comparable results with maximum differences of 0.002 cm3 when adjusted for a standard temperature of 20 °C. The typical uncertainty in the volumes given by both methods is 0.002 cm3. A major source of uncertainty is the volume of the reference weight. The authors conclude that both methods produce consistent results, so that the method of volume calibration at low pressure can be used instead of hydrostatic weighing. The advantage of this approach is that both the masses and volumes of the weights are measured using the same mass comparator, which requires less manipulation. This study will help to establish the procedures for the dissemination and transfer of the mass unit from vacuum to ambient conditions in the institute of the author.

Impact of nanoparticle shape on thermo-solutal buoyancy induced lid-driven-cavity with inclined magnetic-field

The aim of this paper is to numerically investigate the influence of nanoparticles shape on heat and mass transport phenomena in a moving lid cavity under the combined effect of thermo-solutal buoyancy force and magnetic force. The governing equations are transformed into velocity-vorticity form of equations and solved using Galerkin's weighted residual finite-element-technique. The analysis has been carried out with parameters like buoyancy ratio (−5 ≤ N ≤ 5), magnetic field inclination angle (0° ≤ ϕ ≤ 90°) with four shapes of Al2O3 nanoparticle like bricks, blades, platelets and cylinders. The results revealed that the shape factor on Nusselt number is significant depending upon the inclined magnetic field and buoyancy ratio whereas on mass transfer the shape effect is negligible. The diffusion mode of transport process is stronger than the convection mode at higher inclination angle of magnetic field. Based on a given value of N and ϕ, blade and cylinder shows the best performance in Nusselt and Sherwood number respectively except the platelet shape that shows maximum frictional loss in terms of wall shear stress.

Combined effects of buoyancy and electric forces on non-isothermal melting of a dielectric phase change material

Numerical investigations of non-isothermal melting of a dielectric PCM under the combined influence of buoyancy and electric forces have been performed. The coupled set of governing equations which include the Poisson equation for electric potential, Nernst–Planck equation for charge transport, Navier–Stokes equations and the energy equation are implemented in the finite-volume framework of OpenFOAM®. The solid–liquid phase change is modeled by an enthalpy source based approach and temperature dependent dielectric properties have been considered. The dynamic evolution of the electrohydrodynamics (EHD) assisted melting process is analyzed. In the presence of electric field, melting rate curve undergoes a deflection at a point that indicates the shift from natural convection dominated melting to electroconvection dominated melting. The EHD flow compliments the buoyancy driven flow, and the multiple smaller convective rolls of EHD flow enhances the mixing in liquid region. The melting time is a decreasing function of electric Rayleigh number T, whereas, the maximum melt fraction is an increasing function of T. Although the role of Rayleigh number Ra is minimal at higher values of T, Ra determines the occurrence of deflection point. The dielectric force induced by the temperature dependent dielectric properties does not have a significant influence on the melting process, for the parameters considered in this study.