Search

Flash sintering of ceramic powders is a complex process that involves electric, thermal and mechanical phenomena. Modelling should help to better understand and control it, with a view to producing safe and homogeneous parts. A finite element model that couples all relevant phenomena, including the densification and shrinkage of the sintering material, has been worked out for this purpose. This model is used here to investigate the flash sintering of disk-shaped parts. Particular attention is paid to the appearance and growth of heterogeneities within the part, known as hot spots, which are highly dependent on material and process parameters. Leads are provided for limiting the development of such heterogeneities. [ABSTRACT FROM AUTHOR]

African scientific research faces formidable challenges, particularly with limited access to state-of-the-art measurement instruments. The high cost associated with these devices presents a significant barrier for regional research laboratories, impeding their ability to conduct sophisticated experiments and gather precise data. This predicament not only hampers the individual laboratories but also has broader implications for the African scientific community and the advancement of knowledge in developing nations—the financial cost barrier considerably impacts the research quality of these laboratories. Reflection on technical and economical solutions needs to be quickly found to help these countries advance their research. In civil engineering, the thermal conductivity property is the most important measurement for characterizing heat transfer in construction materials. Existing devices (i.e., conductometers) in a laboratory are expensive (approximately EUR 30,000) and unavailable for some African laboratories. This study proposes a new and affordable device to evaluate thermal conductivity in construction materials. The method involves establishing a thermal flux between a heat source (from the Joule effect provided by steel wool where a current is circulating) and a cold source (generated by ice cubes) under steady-state conditions. The development of the cylindrical prototype is based on the comparative flux-meter method outlined in the measuring protocol of the ASTM E1225 standard document. Experiments were conducted on four distinct materials (polystyrene, wood, agglomerated wood, and rigid foam). The results indicate a correct correlation between the experimental values obtained from the newly developed prototype and the reference values found in the literature. For example, concerning the experimental polystyrene study, the detailed case analysis reveals a good correlation, with a deviation of only 4.88%. The percent error found falls within the acceptable range indicated by the standard recommendations of the ASTM E1225 standard, i.e., within 5% acceptable error.

The Inconel 718 superalloy, a precipitation-hardenable material, is of particular interest for applications involving components operating under extreme conditions due to its excellent mechanical properties, high corrosion resistance at temperatures up to 700 °C, and good workability. At high temperatures, thermal transfer processes are crucial for temperature distribution across the component's section, structural transformations, and variations in the alloy's properties. The history of accidental overheating events is critical for the microstructure and properties of the alloy. Studies on thermal transfer in the Inconel 718 alloy available in the literature typically focus on the alloy in its as-delivered state. The experimental research presented in this paper examines the influence of repeated overheating history on the thermal diffusivity of the alloy. [ABSTRACT FROM AUTHOR]

African scientific research faces formidable challenges, particularly with limited access to state-of-the-art measurement instruments. The high cost associated with these devices presents a significant barrier for regional research laboratories, impeding their ability to conduct sophisticated experiments and gather precise data. This predicament not only hampers the individual laboratories but also has broader implications for the African scientific community and the advancement of knowledge in developing nations—the financial cost barrier considerably impacts the research quality of these laboratories. Reflection on technical and economical solutions needs to be quickly found to help these countries advance their research. In civil engineering, the thermal conductivity property is the most important measurement for characterizing heat transfer in construction materials. Existing devices (i.e., conductometers) in a laboratory are expensive (approximately EUR 30,000) and unavailable for some African laboratories. This study proposes a new and affordable device to evaluate thermal conductivity in construction materials. The method involves establishing a thermal flux between a heat source (from the Joule effect provided by steel wool where a current is circulating) and a cold source (generated by ice cubes) under steady-state conditions. The development of the cylindrical prototype is based on the comparative flux-meter method outlined in the measuring protocol of the ASTM E1225 standard document. Experiments were conducted on four distinct materials (polystyrene, wood, agglomerated wood, and rigid foam). The results indicate a correct correlation between the experimental values obtained from the newly developed prototype and the reference values found in the literature. For example, concerning the experimental polystyrene study, the detailed case analysis reveals a good correlation, with a deviation of only 4.88%. The percent error found falls within the acceptable range indicated by the standard recommendations of the ASTM E1225 standard, i.e., within 5% acceptable error. [ABSTRACT FROM AUTHOR]

In recent years, scientists have begun to search for more sustainable biomaterials. Although many studies have been conducted on different fiber-reinforced composites, much remains to be done. Using environmentally friendly composite materials for building insulation is a practical solution to reduce energy consumption. In this study, an advanced statistical approach using JMP software was adopted to manage a complex problem involving multiple parameters. This method was applied to optimize the thermal insulation characteristics of a bio-composite. By following a precisely designed experimental program. the study focuses on analyzing the impact of varying concentrations of date palm fibers (DPF) on the thermal properties of the material. The tested samples contained between 0% and 30% DPF. with a fiber length set at 7 mm. The findings of this study clearly illustrate that the thermal conductivity of the bio-composite decreases with an increase in the percentage of DPF. This phenomenon occurs because the incorporation of fibers into the composite enhances the porosity within the matrix. consequently, reducing its density. Thus. these results underscore the advantageous effect of DPF on the insulation properties of the material. [ABSTRACT FROM AUTHOR]

Aeromagnetic data from nine sheets covering parts of Benue Trough Nigeria were analyzed to identify potential geothermal locations. The aeromagnetic data sheets were analyzed with Oasis Montaj 8.4, Matlab 7.5, Arcmap 10.7.1, and Surfer 13 combined. The centroid depth method was used to spectrally evaluate the depth of high-resolution aeromagnetic data. The findings showed that the research area's geothermal heat flow values range from 88.52259 mW/m2 to 166.2844 mW/m2, while the Curie Point Depth values range from 8.55 km to 16.38 km with a mean depth of 12.2068 km. The Geothermal Gradient values vary from 35.40904 ℃/km to 66.51376 ℃/km with a mean value of 48.85639 ℃/km. The region's mean thermal transfer is 122.1410 mW/m2. It appears that the Curie Point Depth is highest for the lowest thermal transfer values and lowest for the highest thermal transfer values. The study area's heat flow measurements indicate that the crust is oceanic. The comprehensive geothermal data this study provides may aid the study area's exploitation of geothermal energy. Given the extremely high heat flow recorded, there is a likelihood that the studied area has geothermal energy sources. As a result, it was observed that practically the entire study region had substantial heat flow (>80 mW/m2), suggesting the possibility of a geothermal energy source.

A detailed study of the erratic circulation around an unbounded inclined plate under fluctuating temperature and isothermal mass dispersion was carried out with a chemical reaction. This work concentrated on the harmonic inclination of the plate in its plane, and the accurate solution of the non-dimensional governing formulations was made possible by the Laplace transform technique. To evaluate their impact on different profiles, the investigation examined a variety of physical factors, including phase inclination, chemical response variable, Schmidt number, thermal Grashof number, mass Grashof number, and duration. Notably, the speed per second increased with decreasing phase angle. Furthermore, a decrease in either the thermal radiation variable or the chemical response variable induced an increase in velocity. [ABSTRACT FROM AUTHOR]

The experimental and theoretical analysis of viscous dissipation and heat generation/absorption management is crucial in engineering, medical, biological, and exploration activities. This study investigates the analytical solution of viscous heating and thermal gyration of magneto-micropolar fluid particles across a resistive medium with internal non-uniform heat generation/absorption. The formulated partial differential equations were appropriately converted into coupled ordinary differential equations employing similarity variables along with the boundary conditions. The simulation of the resultant equations is carried out using the collocating weighted residual scheme, and the result is validated using the shooting technique via the Runge-Kutta method of order four, Adomian decomposition technique, variational iteration scheme, differential transform method, and quasi-linearization technique as the control methods. Tabular and graphical representations are provided to illustrate the flow characteristics. Taking from the results, the existence of a magnetic field retards the gyration of the fluid particle motion. The spin gradient and vortex viscosity terms reveal the reverse occurrence of micro-rotation distribution, and it is seen that the porosity term suppresses the velocity field. Furthermore, it is observed that the parameters that enhance internal heat generation decrease the viscosity of the fluid in the region. Hence, these findings will assist scientists and engineers to effectively manage heat generation/absorption in industries where effective heat transfer activities are crucial to achieving ideal performance and reducing energy waste.

The thermal behavior of the cladding layer and the flow behavior of the molten pool significantly affect the geometry, temperature distribution and microstructure of the cladding track, thus affecting the mechanical properties of the cladding. Based on the interaction between the laser and powders, a calculation method of the cross-sectional area of the cladding track is proposed. The droplet energy method and the moving grid method are first combined to establish the surface growth model of the cladding track, to calculate the geometry of the cladding track. Then, the temperature field and flow field of the cladding track are studied. The driving forces of the molten pool flow including shear viscosity, gravity, buoyancy, surface tension at the gas-liquid boundary and pressure between liquids are considered to carry out the dynamics study of the molten pool. According to the force condition of the infinitesimal in the molten pool, the dynamic rules and boundary rules of the molten pool are established, so as to solve the flow field of the molten pool. In addition, the calculated geometry of the cladding track is compared with the experimental result to verify the accuracy of the model, and the microhardness of the cladding track is measured. The results show that the relative error between the simulation and the experiment is less than 6%, and the microhardness of the cladding layer is significantly improved. This work can provide a method for studying the morphology, temperature field, and flow field of laser cladding.

In industrial processes such as machining, molding, disc brake operation, and spot welding, the thermal transfer at solid-solid interfaces, particularly with heat generation at the interface, is a critical area of study. This research presents a theoretical framework for addressing the direct problem of thermal conduction in electro-thermal contacts, with a focus on short-term scenarios where heat dissipation occurs through the Joule effect. This aspect, not extensively explored in existing literature, is investigated using a semianalytical method. The study also encompasses a simulation-based exploration, aimed at deepening the understanding of physical phenomena at the contact level. Special attention is given to the thermal transfers initiated at the asperity level of the electro-thermal contact. Findings from this investigation underscore the significance of incorporating the thermal diffusivity of materials into the model for achieving convergence. A notable observation is the increasing divergence over time between the temperatures predicted by numerical and analytical solutions, a trend more pronounced in materials with higher thermal diffusivity, such as titanium. This research contributes valuable insights into the modeling of contact parameters essential for simulating various industrial applications, potentially enhancing efficiency and efficacy in thermal engineering practices. [ABSTRACT FROM AUTHOR]

The traditional curing methods for thermosetting resins are energy-inefficient and environmentally unfriendly. Frontal polymerization (FP) is a self-sustaining process relying on the exothermic heat of polymerization. During FP, the external energy input (such as UV light input or heating) is only required at the initial stage to trigger a localized reaction front. FP is regarded as the rapid and energy-efficient manufacturing of polymers. The precise control of FP is essential for several manufacturing technologies, such as 3D printing, depending on the materials and the coupling of thermal transfer and polymerization. In this review, recent progress on the materials, modeling, and application of FP for thermosetting resins are presented. First, the effects of resin formulations and mixed fillers on FP behavior are discussed. Then, the basic mathematical model and reaction-thermal transfer model of FP are introduced. After that, recent developments in FP-based manufacturing applications are introduced in detail. Finally, this review outlines a roadmap for future research in this field. [ABSTRACT FROM AUTHOR]

The Inconel 718 superalloy, a precipitation-hardenable material, is of particular interest for applications involving components operating under extreme conditions due to its excellent mechanical properties, high corrosion resistance at temperatures up to 700 °C, and good workability. At high temperatures, thermal transfer processes are crucial for temperature distribution across the component’s section, structural transformations, and variations in the alloy’s properties. The history of accidental overheating events is critical for the microstructure and properties of the alloy. Studies on thermal transfer in the Inconel 718 alloy available in the literature typically focus on the alloy in its as-delivered state. The experimental research presented in this paper examines the influence of repeated overheating history on the thermal diffusivity of the alloy.

To comprehensively investigate the evolution of the stress field, a three-dimensional thermodynamic model of laser cladding was developed in this paper. By analyzing the physical process and constructing a mathematical model, the temperature transfer and stress distribution were calculated. The simulation examined the evolution and distribution of stress at various scanning speeds, discussing the interplay between the temperature field and the stress field during rapid heating and cooling. Residual stress was measured through X-ray diffraction in experiments, and the crack distribution within the cladding layer was observed. The findings indicated that the stress values calculated from the simulation model aligned well with the experimental results. By combining experimental data, we conducted a qualitative analysis of the distribution of residual stresses and the trends of crack initiation, leading to the proposal of an optimized processing scheme that significantly enhances the quality and reliability of the cladding layer.

Superhydrophobic surfaces wit ordered hierarchical microstructures were prepared on copper substrates by combining thermal transfer and etching. The surface morphology, wettability, chemical composition and corrosion resistance were, respectively, characterized via scanning electron microscopy, a three-dimensional confocal microscope, contact angle measurement, X-ray diffraction, X-ray photoelectron spectroscopy, electrokinetic polarization and electrochemical impedance spectroscopy techniques. The contact angle of the obtained superhydrophobic surface is up to 153.3° with a reduction in the corrosion current density from 3.9105 × 10−5 A/cm2 to 3.5421 × 10−6 A/cm2 via the electrokinetic polarization curve test, and the maximum capacitive arc radius of the superhydrophobic surface is about 2.5 × 104 Ω cm2 via the electrochemical impedance spectroscopy test, which is two orders of magnitude higher than that of bare copper substrate, and the maximum modulus value |Z| is also two orders of magnitude higher than that of bare copper substrate, indicating that the superhydrophobic surface has better corrosion resistance. This method provides an effective etching approach toward preparing superhydrophobic surfaces with ordered microstructures. [ABSTRACT FROM AUTHOR]

Both oxyhydrogen and butanol are renewable alternative fuels. Based on gasoline/butanol compound injection mode, although the introduction of oxyhydrogen can effectually enhance the optimal BDIr (butanol direct injection ratio), it also leads to an increase in NO emission. Therefore, this paper further studies the influence of lean-burn on the combustion and emission of ternary-fuel combined supply engine with oxyhydrogen/butanol/gasoline. In this paper, three variables are set, namely five BDIr (0–80%), five ONPIv (oxyhydrogen negative pressure inhalation volume) (0–16 L/min) and five λ (1.0–1.4). The results show that the larger the λ, the more significant the impact of oxyhydrogen on improving combustion and thermal transfer inside the cylinder. With the increase of ONPIv, CoVIMEP, CA 10–90 and CA 0-10 decrease, IMEP increases. Under all lean-burn conditions, ONPI can reduce CO and HC emissions. Under the condition of λ = 1.4, when ONPIv = 16 L/min, NO emission is 49.98% lower than the value of the original engine. Moreover, based on BDIr = 40%, 16 L/min ONPIv can elevate the λ limit from 1.41 to 1.83. In summary, “1.1 = λ ≤ 1.2+ONPIv = 16 L/min+60%≤BDIr≤80%” is the excellent control strategy of ONPI + BDI + GPI engine. The synergistic influence of lean-burn and larger BDIr can greatly reduce gasoline consumption and NOx emission caused by oxyhydrogen, but also worsen the mixture combustion atmosphere. ONPI can effectively improve this problem, and further increase energy efficiency. The coupling technology of ternary-fuel combined supply and lean-burn has a positive impact on improving thermal transfer efficiency, optimizing mixture combustion and decreasing gaseous emission.

Project management allows the planning the processes, products, and services necessary for the development of heat transfer calculations. This research developed a solar reactor prototype with an operating temperature range of 170 to 240 °C by deploying project life cycles and the irradiance received in Guadalajara (Mexico). Project management uses the processes of initiation, planning, execution, monitoring, and closure. A conceptually designed solar collector captured the radiation, assuming an irradiance of 1000 W/m2. The startup processes were used to estimate the temperature in the reactor chamber by transfer heat calculations (radiation, convection, and conduction). The planning, execution, and monitoring processes were used to develop the prototype, and closing processes were used to validate its operation through temperature and solar irradiance measurements. The solar reactor prototype provided evidence of its ability to reach an average temperature of 188 °C in a steady state and to receive an average irradiance of 1260 W/m2 in autumn. Heat transfer calculations are valid for developing reactors that work with solar energy and are helpful in geographical areas with similar irradiances. [ABSTRACT FROM AUTHOR]

The main objective of the paper is optimization of the process of thermal transfer in order to obtain - with minimum number of tests and maximum precision - a high adhesion degree of stencils applied to the garments. The major factors affecting the thermal transfer processes are: temperature, pressure, time, and the characteristics of the textile (fiber composition, finishing, structure of the face surface, etc.). The problem is current for most companies that produce clothing for sports and outdoor activities. This category of products is quite complex due to processing technology, combinations of various textile components, cutout components and most importantly the informative and decorative elements applied through thermal transfer process. To optimize the thermal transfer process, a series of experiments with a central rotating compound were applied. Analysis and Interpretation of the results showed that the pressing time is the most important factor of the adhesion of the thermal transfer to the textile material and its ulterior resistance to washing.

Micro-meteorological studies of urban flow and pollution dispersion often assume a neutral atmosphere and often the three-dimensional variation in temperature fields and flow around buildings is neglected in most building energy balance models. The aim of this work is to present the results of development and validation of a three-dimensional tool coupling thermal energy balance of the buildings and modelling of the atmospheric flow and dispersion in urban areas. To do so, a 3D microscale atmospheric radiative scheme has been developed in the atmospheric module of the computational fluid dynamics (CFD) code Code_Saturne adapted to detailed building geometries. The full coupling of the radiative transfer and fluid dynamics models has been validated with idealized cases. In this paper, our focus is to simulate and compare with measurements the diurnal evolution of the brightness surface temperatures and the momentum and energy fluxes for a neighborhood in the city center of Toulouse, in the southwest part of France. This is performed by taking into account the 3D effects of the flow around the buildings and all thermal exchanges, in real meteorological conditions, and compare them to aircraft infrared images and in situ measurements on a meteorological mast. The calculation mesh developed for the city center and the simulation conditions for the selected day of the field campaign are presented. The results are evaluated with the measurements from the Canopy and Aerosol Particles Interactions in TOulouse Urban Layer experiment (CAPITOUL). In addition, the second purpose of this work is to investigate a hypothetical release of passive pollutant dispersion in the same area of Toulouse under different thermal transfer conditions for the street and the buildings surfaces: neutral and 3D radiative transfer heating. The presence of heat transfer continually modifies the airflow field while the airflow in the neutral case reaches a stationary state. Compared to the neutral case, taking into account the thermal transfer enhances the turbulence kinetic energy and vertical velocity (especially at the roof level) due to buoyancy forces. The simulation results also show that the thermal effects considerably alter the plume shape. [ABSTRACT FROM AUTHOR]

The turbulent convective thermal transfer in channel heat exchangers (CHEs) is studied numerically via the CFD (Computational Fluid Dynamics) method. Deflectors are inserted on the hot bottom walls of the heat channel to enhance the hydrothermal characteristics. Various shapes of in-line deflectors are considered, namely: rectangular (a/b = 0.00), cascaded rectangular-triangular (a/b = 0.25, 0.50, and 0.75), and triangular (a/b = 1.00) shapes. From the obtained results, the inclusion of in-line deflectors with a/b = 0.75 has given the most significant thermal enhancement factor, which was higher than that for a/b = 0.00, 0.25, 0.50, and 1.00 by about 5.36, 5.06, 67.27, and 3.88%, respectively. Also, the in-line cascaded deflector’ case (a/b = 0.75) shows an increase in the enhancement factor (η) from 4 to 15.44% over the cases of one deflector (corrugated, rectangular, triangular, trapezoidal, arc, (+), S, 45° V, 45° W, T, Γ, and ε-shaped) or two deflectors (staggered corrugated). This highlights the effectiveness of in-line cascaded rectangular-triangular deflectors with a/b = 0.75 in improving the performance of the proposed exchanger for the conditions adopted.

The turbulent convective thermal transfer in channel heat exchangers (CHEs) is studied numerically via the CFD (Computational Fluid Dynamics) method. Deflectors are inserted on the hot bottom walls of the heat channel to enhance the hydrothermal characteristics. Various shapes of in-line deflectors are considered, namely: rectangular (a/b = 0.00), cascaded rectangular-triangular (a/b = 0.25, 0.50, and 0.75), and triangular (a/b = 1.00) shapes. From the obtained results, the inclusion of in-line deflectors with a/b = 0.75 has given the most significant thermal enhancement factor, which was higher than that for a/b = 0.00, 0.25, 0.50, and 1.00 by about 5.36, 5.06, 67.27, and 3.88%, respectively. Also, the in-line cascaded deflector' case (a/b = 0.75) shows an increase in the enhancement factor (η) from 4 to 15.44% over the cases of one deflector (corrugated, rectangular, triangular, trapezoidal, arc, (+), S, 45° V, 45° W, T, Γ, and ε-shaped) or two deflectors (staggered corrugated). This highlights the effectiveness of in-line cascaded rectangular-triangular deflectors with a/b = 0.75 in improving the performance of the proposed exchanger for the conditions adopted. [ABSTRACT FROM AUTHOR]

Flat air solar collectors are used for heat transfer between the absorber and the heat transfer fluid, to improve this transfer there are several methods. Among these methods, the exchange surface lengthening and the creation of turbulence. In this work is done to give a comparison between two types of solar collectors, so we have made an improvement of Ben Slama Romdhane's solar collector by creating two air flow passages to increase heat transfer. We made a 3D simulation of a flat air solar collector with transverse baffles which causes turbulence and increases the exchange surface; we use the ANSYS calculation code to make the simulation and gives results with a brief time and minimal cost. [ABSTRACT FROM AUTHOR]

The paper presents the modeling and simulation of heat transfer in ANSYS in a room of a house. The house is a three-room apartment located in Resita, Caras-Severin. The room where the heat transfer was studied is the coolest room in the apartment. The mathematical model of heat transfer was developed and then based on this mathematical model the numerical model with finite elements was elaborated, thus making possible the simulation of the thermal transfer in ANSYS. The results obtained can help the homeowner in the correct sizing of the heating system. [ABSTRACT FROM AUTHOR]

The TiO2-water based nanofluid flow in a channel bounded by two porous plates under an oblique magnetic field and variable thermal conductivity is formulated as a boundary-value problem (BVP). The BVP is analytically solved with the homotopy analysis method (HAM). The result shows that the concentration of the nanoparticles is independent of the volume fraction of TiO2 nanoparticles, the magnetic field intensity, and the angle. It is inversely proportional to the mass diffusivity. The fluid speed decreases whereas the temperature increases when the volume fraction of the TiO2 nanoparticles increases. This confirms the fact that the occurrence of the TiO2 nanoparticles results in the increase in the thermal transfer rate. The fluid speed decreases and the temperature increases for both the pure water and the nanofluid when the magnetic field intensity and angle increase. The maximum velocity does not exist at the middle of the symmetric channel, which is in contrast to the plane-Poiseuille flow, but it deviates a little bit towards the lower plate, which absorbs the fluid with a very low suction velocity. If this suction velocity is increased, the temperature in the vicinity of the lower plate will be increased. An explicit expression for the friction factor-Reynolds number is then developed. It is shown that the Hartmann number of the nanofluid is smaller than that of pure water, while the Nusselt number of the nanofluid is larger than that of pure water. However, both the parameters increase if the magnetic field intensity increases. [ABSTRACT FROM AUTHOR]

Computational fluid dynamic simulations were conducted to analysis the influences of two different deflector orientations on turbulent forced-convection flow and skin friction loss of two-dimensional horizontal rectangular cross section channels with upper and lower wall-attached corrugated baffles. The governing flow equations, i.e., continuity, momentum, and energy, were numerically solved by the Finite Volume Method (FVM) using the Semi-Implicit Method for Pressure Linked Equation (SIMPLE) discretization formulation. The help of the CFD code FLUENT was employed to solve the dynamic and thermal behavior of air in the whole domain under investigation. The flow rate in terms of Reynolds number is ranged from 5,000 to 32,000. The obtained results show that augmenting the Reynolds number makes the dynamic thermo energy field redirect in the vicinity of deflector corners, and forces an augmentation in the thermal transfer rate from baffles. [ABSTRACT FROM AUTHOR]

Heat treatment can substantially improve the quality of wood materials. Temperature is the most important factor during heat treatment affecting the properties of boards, so optimizing the treatment process should include careful investigation of thermal transfer phenomena. In this work, the transient heat transfer characteristics during the heat treatment of wood at 120 °C, 150 °C, and 180 °C were numerically studied per the temperature distribution and variation in sample boards. The heat transfer model was established by comparative analysis of the experimental data and simulation data. ANSYS software was used to simulate heat transfer during the process of wood heat treatment; simulation results were consistent with experimental results at average relative error within 5%. This accurate simulation of heat transfer within wood samples provides useful insight into the heat transfer mechanisms. [ABSTRACT FROM AUTHOR]

Background and Aim : Along with improvements in aesthetics and longevity of restorations, finishing and polishing, can produce potentially injurious temperature rise within the pulp chamber. The purpose of the current study was to find whether different polishing methods and thickness of composites have any effect on temperature rise of composite restorative materials . Materials and Methods : Sixty composite resin specimens 9 mm in diameter were prepared and assigned to three experimental groups with three sample thicknesses (2, 3 and 4mm). Each group was divided into four subgroups randomly. Polishing in subgroups 1 and 2 (continuous and intermittent dry polishing) and subgroups 3 and 4 (continuous and intermittent wet polishing) was carried out with a slow speed contra-angle hand piece at a medium speed for 120 seconds in a roll on motion. Immediately after polishing, temperature was measured on the top and bottom surface of each sample using a laser thermometer. One and two way ANOVA, Duncan, and paired T-test was used to analyze the data . Results: The mean temperature rise after polishing in different methods was significant continuous dry polishing produced the maximum temperature rise. In addition, increasing the thickness of composite resin up to 4mm did not significantly affect thermal transfer from the top surface to the base during polishing . Conclusion : Copious use of water coolant during finishing and polishing procedures is considered a simple and effective method for pulpal protection. Increasing the thickness of composite resin does not have a significant role in compensating the heat generated during polishing procedure .