Browsing by Subject "Finite volume method"
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Item Numerical study of heat transfer due to twinjets impingement onto an isothermal moving plate(Association for Scientific Research, 2013) Başaran A.; Selimefendigil F.In this study, heat transfer from a moving isothermal hot plate due to double impinging vertical slot jets was investigated for a laminar flow. The rectangular geometry consists of a confining adiabatic wall placed parallel to the moving impingement. The jets are located symmetrically at mid point of upper wall. Water and Al2O3 nanoparticles mixture with different volumetric fraction was used as working medium. In considered jet impingement problem, the effects of the jet exit Reynolds numbers, ranging from 50 to 200, the normalized plate velocity, ranging from 0 to 2, and volumetric fractions of nanofluid, ranging from 0% to 6% were investigated. The commercial software package based on finite volume method FLUENT (version 6.3.26) is used in this study for the computations. It has been observed that increasing normalized plate velocity increases the heat transfer from bottom surface. Similarly, increasing Reynolds number of slot jets leads to enhancement of heat transfer. Besides, increasing volumetric fraction of nanofluid conributes to heat transfer enhancement.Item Numerical Analysis of Mixed Convection of Nanofluids Inside a Vertical Channel(World Scientific Publishing Co. Pte Ltd, 2016) Akgül M.B.; Pakdemirli M.Laminar mixed convection of an Al2O3/water nanofluid inside a vertical channel is investigated numerically. Single-phase and two-phase Eulerian models are employed to analyze flow and thermal fields of the nanofluid in conjunction with the suitable expressions for the particle viscosity and effective particle thermal conductivity. The results of two-phase Eulerian model are compared with the single-phase model and with the published experimental data. Effects of the solid volume fraction, Reynolds number and Grashof number on the heat transfer performance of the nanofluid are investigated and discussed in detail. © 2016 World Scientific Publishing Company.Item Numerical analysis of heat transfer in a flat-plate solar collector with nanofluids(Begell House Inc., 2017) Yurddaş A.; Çerçi Y.Heat transfer aspects of a typical flat-plate solar collector utilizing water-based nanofluids as the working fluid were analyzed numerically. Water-based nanofluids of various compositions containing metallic Al2O3 and Cu nanoparticles with volume fractions ranging from 1% to 5% were examined, and the effects of the nanofluids on the heat transfer were quantified. Relevant parameters such as the heat flux, Reynolds number, and the collector tilt angle were calculated and compared to each other at different boundary conditions. The flat-plate solar collector geometry was simplified, and only a fluid carrying pipe with an absorber surface was chosen as a numerical model with a particular at ention to symmetry, instead of taking the entire collector geometry. The numerical model was controlled and confirmed by applying it to similar studies existing in the pertinent literature. All numerical solutions were carried out by using a commercial finite volumes of ware package called ANSYS Fluent. The results show that the nanofluids increase the heat transfer rate ranging from 1% to 8%, when compared to water as a working fluid. © 2017 by Begell House, Inc.Item Forced convection and thermal predictions of pulsating nanofluid flow over a backward facing step with a corrugated bottom wall(Elsevier Ltd, 2017) Selimefendigil F.; Öztop H.F.In this study, laminar forced convection of pulsating nanofluid flow over a backward-facing step with a corrugated bottom wall was numerically examined by using finite volume method. Part of the bottom wall downstream of the step was corrugated and kept at constant temperature. Effects of Reynolds number, length and height of the surface corrugation wave, nanoparticle volume fraction, amplitude and frequency of flow pulsation on the fluid flow and heat transfer were numerically investigated. It was observed that average Nusselt number enhances as the Reynolds number, length and height of the corrugation wave increase. Average Nusselt number versus Strouhal number shows a resonant type behavior and flow pulsation amplitude increment results in heat transfer enhancement. Average heat transfer rate increases with the inclusion of the nanoparticles but the rate of enhancement depends on the nanoparticle solid volume fraction interval. An efficient computational strategy for the thermal performance prediction of the system was developed by using proper orthogonal decomposition and artificial neural networks. © 2017 Elsevier LtdItem Effects of nanoparticle shape on slot-jet impingement cooling of a corrugated surface with nanofluids(American Society of Mechanical Engineers (ASME), 2017) Selimefendigil F.; Öztop H.F.Numerical study of jet impingement cooling of a corrugated surface with water-SiO2 nanofluid of different nanoparticle shapes was performed. The bottom wall is corrugated and kept at constant surface temperature, while the jet emerges from a rectangular slot with cold uniform temperature. The finite volume method is utilized to solve the governing equations. The effects of Reynolds number (between 100 and 500), corrugation amplitude (between 0 and 0.3), corrugation frequency (between 0 and 20), nanoparticle volume fraction (between 0 and 0.04), and nanoparticle shapes (spherical, blade, brick, and cylindrical) on the fluid flow and heat transfer characteristics were studied. Stagnation point and average Nusselt number enhance with Reynolds number and solid particle volume fraction for both flat and corrugated surface configurations. An optimal value for the corrugation amplitude and frequency was found to maximize the average heat transfer at the highest value of Reynolds number. Among various nanoparticle shapes, cylindrical ones perform the best heat transfer characteristics in terms of stagnation and average Nusselt number values. At the highest solid volume concentration of the nanoparticles, heat transfer values are higher for a corrugated surface when compared to a flat surface case. © 2017 by ASME.Item Numerical analysis and ANFIS modeling for mixed convection of CNT-water nanofluid filled branching channel with an annulus and a rotating inner surface at the junction(Elsevier Ltd, 2018) Selimefendigil F.; Öztop H.F.Numerical study for mixed convection of CNT-water nanofluid flow in a branching channel with annulus at the junction and a rotating surface was performed by using finite volume method. This geometry can be used in a variety of engineering applications such as in geothermal, gas pipelines, in pharmaceutical, fuel cells and many others. The numerical simulations are performed for various values of pertinent parameters such as Richardson number, angular rotational velocity of the inner surface at the annulus junction, solid nanoparticle volume fraction and diameter of the inner rotating. It was observed that the recirculation regions established within the annulus and separated fluid zones on the walls of the branching channel near the junction are strongly influenced by the by rotation of the inner surface at the annulus. The average Nusselt number enhancements up to 64% are obtained for the nanofluid containing the highest particle volume fraction for Ri = 0.01 and Ri = 1 when the inclination angle of the lower branching channel is 45°. Finally, ANFIS modeling technique with triangular-shaped membership function and 48 fuzzy rules are used to predict the average Nusselt numbers for the hot walls of the channel and annulus part. © 2018 Elsevier LtdItem Forced convection of pulsating nanofluid flow over a backward facing step with various particle shapes(MDPI AG, 2018) Chamkha A.J.; Selimefendigil F.In this study, numerical analysis of forced convective pulsating nanofluid flow over a backward-facing step with different nanoparticle shapes was performed by the finite volume method. The effects of the Strouhal number (between 0.1 and 2), solid nanoparticle volume fraction (between 0 and 0.04) and nanoparticle shapes (spherical, blade and cylindrical) on the heat transfer and fluid flow were examined with the aid of numerical simulation. It was observed that the average Nusselt number is a decreasing function of the Strouhal number for the considered range, and it enhances for higher solid particle fractions. Using nanofluids with spherical particles is advantageous in pulsating flow, whereas cylindrically-shaped particles are preferred in steady flow configurations. Average Nusselt number enhancements up to 30.24% and 27.95% are achieved with cylindrical- and spherical-shaped particles at the highest volume fraction. © 2018 by the authors.Item Mixed convection of nanofluid over a backward facing step under the effects of a triangular obstacle and inclined magnetic field(Begell House Inc., 2018) Selimefendigil F.; Oztop H.In this study, laminar mixed convection of CuO–water nanofluid over a backward facing step with the presence of a triangular obstacle and under the effect of magnetic field was numerically investigated. Finite volume method was used to solve the governing equations for the range of parameters: Richardson number (between 0.01 and 100), Hartmann number (between 0 and 50), nanoparticle volume fraction (between 0 and 0.04), and horizontal location of the triangular obstacle (between 0.5H and 2H). It was observed that average heat transfer is a decreasing function of Richardson number and an increasing function of nanoparticle volume fraction. The dependence of average heat transfer on the magnetic field parameters shows a resonant-type behavior. The obstacle affects the local Nusselt number distribution near the step especially for lower values of Richardson number and Hartmann number. Artificial neural networks were used to develop models that can be used instead of high-fidelity computational fluid dynamics simulations for fast and accurate thermal performance predictions of the considered system. © 2018 by Begell House, Inc.Item Analysis and predictive modeling of nanofluid-jet impingement cooling of an isothermal surface under the influence of a rotating cylinder(Elsevier Ltd, 2018) Selimefendigil F.; Öztop H.F.In this paper, numerical study and thermal prediction for a nanofluid jet impingement cooling of an isothermal hot surface with an adiabatic rotating cylinder were performed. Finite volume method was used for the solution of resulting governing equations along with the boundary conditions. Influence of various pertinent parameters such as Reynolds number (between 100 and 400), angular rotational velocity of the cylinder (between −0.1 and 0.1), horizontal location of the cylinder (between 0 and 3.75w) and solid particle volume fraction (between 0 and 0.04) on the fluid flow thermal characteristics were examined. It was observed that cylinder rotation and its location affect the cooling performance of the hot surface. It can be used as control element for heat and fluid flow. At the highest angular rotational speed as compared to motionless cylinder case, average Nusselt number reduces by about 20.16% for clockwise rotation. Solid particle addition to the base fluid affects the variation of first and secondary peaks in the Nusselt number along the hot wall. At the highest solid when the cylinder is away from the inlet slot and average Nusselt number enhancement is by about 8.08% at the highest volume fraction. An efficient modeling strategy was developed based on proper orthogonal decomposition and radial basis neural networks for thermal predictions. Accurate and fast results were achieved as compared to high fidelity computational fluid dynamics simulation results. © 2018 Elsevier LtdItem Experimental and numerical studies on improvement of heat transfer of OLED TVs; [OLED TV’lerin ısı transferinin iyileştirilmesi üzerine deneysel ve nümerik çalışmalar](Gazi Universitesi Muhendislik-Mimarlik, 2019) Nil M.; Öztürk Y.; Akgül M.B.; Sarı G.In this study, the thermal behaviors of organic light emitting diodes (OLED) televisions are investigated experimentally and numerically. Organic light emitting diodes are very sensitive to temperature. For this reason, the heat emitted from the diodes must be removed quickly from the environment. The study consists of two parts. In the first part, the use of an effective heat spreader between the screen and the metal casing is proposed as a mechanism for improving the temperature distributions for heat transfer. Pyrolytic graphite plate and tempered pyrolytic graphite plate were used as heat spreader. The graphical heat transfer coefficients of the graphite plates are considerably higher than in the normal direction. The effectiveness of these proposed mechanisms is demonstrated by simulation. As an example model, OLED TV was selected in 15 "dimensions and both experimental and numerical thermal analyzes were performed. The temperature distributions of the OLED were obtained with the help of the ANSYS ICEPAK program, a commercial code that uses the finite volume method. Simulation and test results are obtained very close to each other. The thermal management contributions of OLED TVs using different thicknesses of pyrolytic and tempered pyrolytic graphite plates are presented experimentally and numerically. In the second part, a dual action piezo fan design is proposed. The design parameters of the piezo fan were determined and the numerical analyzes for these parameters were made with the Comsol Multiphysics program. Experimental measurements were made for design dimensions determined by numerical analysis. The result is that the use of a dual-acting piezo provides more efficient cooling than the existing synthetic jets. © 2019 Gazi Universitesi Muhendislik-Mimarlik. All rights reserved.Item Optimization and thermal performance of evacuated tube solar collector with various nanofluids(Elsevier Ltd, 2020) Yurddaş A.Evacuated tube solar collectors (ETSC) constitute an important place among water heating systems. The use of solar energy systems will reduce CO2 and SO2 emissions for green nature. In this context, geometric and technical values of the open-ended ETSC systems were optimized by considering different parameters. In the optimization study, the solar tube collector with vacuum tube which gives the most appropriate results was discussed and its effects on heat transfer according to the presence of different work fluids were investigated. For this study, a numerical study was carried out by applying the finite volume method, one of the computational fluid dynamics methods. We confirmed our numerical study with both experimental and numerical studies. In our study, water and water-based nano-fluids are used as heat transfer fluid in 24 heat tubes with 30º inclination and the related tank that connected to it. The water-based nano-fluids we used are water as the basic fluid and MWCNT, TiO2, SiO2 and Cu as the nanoparticles. We modeled nanofluids homogeneously by handling them for different volumetric ratios. The thermal and hydrodynamic conditions of the collector were investigated using the Boussinesq Approach and the tank exit temperatures were determined. As a result of this study, it was seen that the use of nano-fluids improved the heat transfer in the ETSCs and the best thermal recovery among the nano-fluids we used in our study was realized in Cu-Water nano-fluid. Improving the thermal performance of the ETSC is important for better energy conversion. For this reason, the effects of nano-fluid usage on thermal performance in solar energy systems of pollution-free energy are promising. © 2020Item Cooling of an isothermal surface having a cavity component by using CuO-water nano-jet(Emerald Publishing, 2020) Selimefendigil F.; Chamkha A.J.Purpose: The purpose of this study is to numerically analyze the convective heat transfer features for cooling of an isothermal surface with a cavity-like portion by using CuO-water nano jet. Jet impingement cooling of curved surfaces plays an important role in practical applications. As compared to flat surfaces, fluid flow and convective heat transfer features with jet impingement cooling of a curved surface becomes more complex with additional formation of the vortices and their interaction in the jet wall region. As flow separation and reattachment may appear in a wide range of thermal engineering applications such as electronic cooling, combustors and solar power, jet impingement cooling of a surface which has a geometry with potential separation regions is important from the practical point of view. Design/methodology/approach: Numerical simulations were performed with a finite volume-based solver. The study was performed for various values of the Reynolds number (between 100 and 400), length of the cavity (between 5 w and 40 w), height of the cavity (between w and 5w) and solid nano-particle volume fraction (between 0 and 4 per cent). Artificial neural network modeling was used to obtain a correlation for the average Nusselt number, which can be used to obtain fast and accurate predictions. Findings: It was observed that cavity geometrical parameters of the cooling surface can be adjusted to change the flow field and convective heat transfer features. When the cavity length is low, significant contribution of the inclined wall of the cavity on the average Nusselt number is achieved. As the cavity length and height increase, the average Nusselt number, respectively, reduce and slightly enhance. At the highest value of cavity height, significant changes in the convective flow features are obtained. By using nanofluids instead of water, enhancement of average heat transfer in the range of 35-46 per cent is obtained at the highest particle volume fraction. Originality/value: In this study, jet impingement cooling of an isothermal surface which has a cavity-like portion was considered with nanofluids. Addition of this portion to the impingement surface has the potential to produce additional vortices which affects the fluid flow and convective features in the jet impingement heat transfer. This geometry has the forward-facing step for the wall jet region with flow separation reattachment in the region. Based on the above literature survey and to the best of the authors’ knowledge, jet impingement cooling for such a geometry has never been reported in the literature despite its importance in practical thermal engineering applications. The results of this study may be useful for design and optimization of such systems and to obtain best performance in terms of fluid flow and heat transfer characteristics. © 2019, Emerald Publishing Limited.Item Hydro-thermal performance of CNT nanofluid in double backward facing step with rotating tube bundle under magnetic field(Elsevier Ltd, 2020) Selimefendigil F.; Öztop H.F.In this study, a novel method for convective heat transfer control of flow past a double backward facing step with combined effects of oriented magnetic field, rotating tube bundle and inclusion of highly conductive CNT nanoparticles in the base fluid is offered. Hydro-thermal performance assessment of double backward facing step is numerically performed with finite volume method in laminar flow regime. Effects of Reynolds number, rotational Reynolds number, circular cylinder arrangement and horizontal local of the tube bundle, distance between the steps and magnetic field strength on the fluid flow, heat transfer, pressure drop and hydro-thermal performance coefficient variation are examined. The rotation of the cylinder, arrangement and location were found to alter hydro-thermal performance while the average Nu is enhanced with higher Reynolds and Hartmann numbers. The presence of the upper vortex location resulted in higher deflection of the main stream toward the hot bottom wall which resulted in higher local heat transfer rates. This is especially the case for clockwise direction rotation at the height speed and local Nu value increment is 244% as compared to non-rotating cylinder case. Best performance coefficient is obtained with MHD flow at Hartmann number of 5 while performance increase is 13% as compared to non-magnetic field configuration. The vertical size and location of the upper vortex changes with the horizontal location of the tube bundle and spacing between the steps. As compared to reference configurations, variations in the hydrothermal performance coefficients are 15% and 20% when varying the horizontal location and distance between the steps. The CNT nanoparticles inclusion in the base fluid resulted in performance coefficient enhancement of 52% at the highest solid volume fraction. As flow separation and subsequent attachments are encountered in a variety of heat transfer engineering applications, the results of the present work will be helpful in the design and optimization of various thermal engineering systems. © 2020 Elsevier LtdItem Magnetohydrodynamics forced convection of nanofluid in multi-layered U-shaped vented cavity with a porous region considering wall corrugation effects(Elsevier Ltd, 2020) Selimefendigil F.; Öztop H.F.Magnetohydrodynamics forced convection of CNT-water nanofluid in a layered U-shaped vented cavity involving a porous region is investigated under the impact of wall corrugation. The numerical study is performed by using the finite volume method. Impacts of Reynolds number (between 100 and 1000), Hartmann number (between 0 and 50), Darcy number (between 10−4 and 5 × 10−2), porous layer height (between 0.1H and 0.5H), height (between 0 and 0.5H) and number of triangular waves (between 1 and 16) and curvature (between 0.01H and 0.2H) at the U-turn of the vented cavity on the convective heat transfer features are examined. The flow field and heat transfer are affected by variations in the Reynolds number, magnetic field strength and permeability of the porous medium. The average Nusselt number increases significantly with higher magnetic field strength and at Hartmann number of 50, the amount of enhancement is 112% while the impact is reverse for highest value of Darcy number of the porous compound. The corrugation of the bottom wall which is a triangular wave was found to be used as an effective tool for fluid flow and heat transfer features. The average heat transfer rate reduces with higher number of corrugation waves (68.2% reduction) while it first increases then reduces with higher height of the corrugation. The curvature of the neck in the U-shaped cavity reduced the heat transfer rate which is 15.5% at the highest value. © 2020 Elsevier LtdItem Solidification of PCM with nano powders inside a heat exchanger(Elsevier B.V., 2020) Hajizadeh M.R.; Selimefendigil F.; Muhammad T.; Ramzan M.; Babazadeh H.; Li Z.Present research was devoted to modeling investigation of paraffin solidification within a wavy channel. Paraffin was mixed with CuO nano powders and creates NEPCM. Changing the surface of duct and working PCM is the main factors of this paper for improving the performance. The outer duct contains NEPCM and air within inner side can be warmer due to discharging process. The outputs indicate that wavy duct has better performance than the straight one due to its shorter solidification duration. Utilizing wavy duct and NEPCM can help the solidification and enhance the rate of process about 38%. Inclusion of nanomaterial leads to lower discharging time. © 2020 Elsevier B.V.Item Effects of local curvature and magnetic field on forced convection in a layered partly porous channel with area expansion(Elsevier Ltd, 2020) Selimefendigil F.; Öztop H.F.In this study, local curvature effects of upper wall on the separated flow and heat transfer features are numerically examined for a layered channel which contains porous and nanofluid (CNT-water) layers with sudden area expansion under the magnetic field effects. Finite volume method was used for the numerical simulations and impact of different pertinent parameters such as Reynolds number (between 100 and 400), Hartmann number (between 0 and 20), local curvature of the upper wall (r1 between 2H and 10H, r2 between 0 and 2H), porous medium Darcy number (between 10−4 and 5×10−2), size of the porous layer (between H and 20H) on the convective heat transfer features are numerically analyzed. A novel multi-domain POD approach was used for estimation of flow variables and heat transfer rate. It was observed that the heat transfer rate is enhanced with higher values of Reynolds number, Hartmann number and Darcy number. The peak value and the average value of Nusselt number increase by about 12.86% and 22.48% with magnetic field effects at Ha = 20 when compared to case without magnetic field.There is slight impact of the porous layer size on the fluid flow and heat transfer. However, impact of the curvature of the upper wall on the convective heat transfer feature is significant. The maximum value of local Nusselt number increases up to 4.76 times and therefore it can be used an excellent tool for convective heat transfer control. © 2020 Elsevier LtdItem NUMERICAL INVESTIGATION OF THERMAL AND FRICTION CHARACTERISTICS OF TURBULENT FLOW THROUGH A CIRCULAR TUBE WITH PLATE INSERTS(Begell House Inc., 2021) Baysal E.; Bademci N.In this study, a plate-type turbulator placed in a circular tube and analysis of the turbulators with different pitches and different fin angles formed on the plate were investigated numerically. Heat transfer performance and friction factor were investigated for Reynolds number 4000-30,000 for each type of turbulator. The basic conservation equations are solved in the steady state in 3D under the turbulent flow conditions by using the ANSYS Fluent commercial code with the realizable k-e turbulence model based on the finite volume method. Numerical analysis results were obtained in the study conducted according to different flow rates of air. As a result of the analysis, it was observed that the Nusselt number increased depending on the Reynolds number as the fin pitch distance became shorter and the fin angle increased. The use of each turbulator provided thermal improvement compared to the empty heat exchanger, and the highest thermal performance was obtained with the Modj 60° turbulator at a rate of 208.57%. In addition, the effects of the obtained temperature contours and velocity vectors on the flow characteristics of the turbulator in the heat exchanger were investigated. © 2021 Begell House Inc.. All rights reserved.Item Assessments of thermal performance of hybrid and mono nanofluid U-tube solar collector system(Elsevier Ltd, 2021) Yıldırım E.; Yurddaş A.Solar energy systems are of great importance for water heating, where we spend most of the energy. U-tube solar collectors have a very important place in water heating among solar energy systems. Compensation of the intense energy used for water heating by this type of environmentally friendly solar energy system, will reduce CO2 and SO2 emissions for a cleaner nature. Therefore; the thermal performance of a U-tube complete system from evacuated tube solar collector (ETSC) systems was assessed. The heat transfer capability of the system, which contains 10 U-tubes, has been examined by considering the fact that it has different work fluids and different heat fluxes and flow rates. The finite volume method is used for this analysis. The model has been verified by many experimental and numerical studies. In the system under consideration has been used 10 vacuum U-tubes inclined at 30°, and water and nanofluid (SiO2 - Cu) which were used as working fluid in the manifolds connected to these tubes. Nanoparticles modeled in the work fluid are considered as hybrid and mono at different volume fractions. The thermal and hydrodynamic behaviors of the system have been examined by taking into account the Boussinesq approach, and the system outlet temperatures have been calculated. As a result of analyzes and comparisons made, it has been seen that the use of nanofluid improves the thermal capability of the system under consideration. It has been determined that this improvement reaches up to 15% compared to water. The thermal effects of using SiO2 nanoparticles, which are lighter than Cu nanoparticles, were observed in terms of the precipitation problem encountered in many systems when using hybrid nanofluids. Thus, instead of using more Cu nanoparticles in volume, using smaller amounts together with SiO2 nanoparticles as a hybrid both eliminates the problem of precipitation and improves the heat capability of the work fluid. © 2021 Elsevier LtdItem Impact of a rotating cone on forced convection of Ag–MgO/water hybrid nanofluid in a 3D multiple vented T-shaped cavity considering magnetic field effects(Springer Science and Business Media B.V., 2021) Selimefendigil F.; Öztop H.F.Forced convection of hybrid Ag–MgO/water nanofluid in a three-dimensional T-shaped vented cavity with multiple ports under the effects of a inner rotating cone and magnetic field is numerically studied with finite volume method. The simulation is performed for various values of parameters such as: Reynolds number (between 100 and 1000), Hartmann number (between 0 and 60), angular velocity of the rotating cone (between − 200 rad/s and 0), aspect ratio of the circular cylinders of the base of the cone (between 0.5 and 2) and nanoparticle solid volume fraction of the hybrid nanofluid (ϕ1 between 0 and 0.01, ϕ2 between 0 and 0.01). It was observed that the average heat transfer rate rises with higher values of Reynolds number, Hartmann number above a specified value, angular rotational speed of the cone, aspect ratio of the cone for values above 1 and solid nanoparticle volume fractions of the hybrid particles. In total, 61% of average heat transfer enhancement for left horizontal upper surface is achieved with the imposed magnetic field. The enhancement in the average Nusselt numbers is 25.6% for the rotating cone at the highest angular velocity as compared to a motionless one. The average heat transfer increases almost linearly with hybrid solid nanoparticle volume fraction, while 8.96% and 15.52% enhancements are obtained for varying the solid volume fraction of the particles with the lower and higher thermal conductivity up to 0.01. © 2020, Akadémiai Kiadó, Budapest, Hungary.Item Forced convection laminar pulsating flow in a 90-deg bifurcation(American Society of Mechanical Engineers (ASME), 2021) Selimefendigil F.; Oztop H.F.; Khodadadi J.M.Numerical investigation of laminar forced convection of pulsating flow in a 90-deg bifurcation was performed with the finite volume method. The inlet velocity varies sinusoidally with time while constant wall temperature is utilized. The working fluid is air with constant properties and the numerical work is conducted for a range of the Reynolds numbers (100–2000), dividing flowrates (0.3–0.7) and Strouhal numbers (0.1–10). It is observed that the amplitudes of oscillating heat transfer are damped as the value of the Strouhal number increases. The average value of Nu number rises for higher Reynolds number and the dividing flowrate for the downstream wall of the y-channel branch. As the value of the dividing flowrate increases from 0.3 to 0.7, heat transfer is less effective in the vicinity of the branch at the Reynolds number of 500. The effects of the Reynolds number on the average Nu number variation is more pronounced for the y-branch wall for different values of dividing flowrates. Resonant type behavior of average Nu number is obtained for the y-branch channel for diving flowrates of 0.3 and 0.5. Copyright © 2020 by ASME