Thermophysical Properties Of Fluids Research Articles

Synthesis and thermophysical properties of functionalized graphene quantum dots for enhancing heat transfer of conventional fluid

For the past few years, graphene quantum dots have been utilized in versatile applications due to their ultra-small size, non-toxicity, high heat transfer capacity, water solubility, and biocompatibility. In the presented work, the graphene quantum dots (GQD) is utilized to improve the thermophysical properties of conventional heat transfer fluid. In this research, the polyalkyline glycol (PAG) has been used as a conventional heat transfer fluid. The graphene quantum dots have been synthesized using hydrothermal method and further functionalized for the proper dispersion in PAG. The novel nanofluid has been synthesized using functionalized graphene quantum (FGQD) with based fluid as PAG. The FGQD-PAG nanofluid is synthesized with very lower concentrations of 100 ppm, 200 ppm, and 500 ppm. In order to investigate heat transfer capacity, each concentration of nanofluid has been investigated for thermal conductivity and viscosity. The experimental result shows that 500 ppm of FGQD-PAG lubricant improves the thermal conductivity by 2 W/mk. Also, the optimal viscosity for the nanofluid is observed with 100 ppm of FGQD-PAG based nanofluid. Further, it is observed that the use of graphene quantum dots with PAG base fluid is stable and does not require any use of surfactant for the dispersion. From this research, the problem of aggregation, agglomeration and precipitation occurring due to vander waal force has been addressed and is resolved by covalent surface modification. Thus, it is concluded that the graphene quantum dots can be effectively utilized in industrial applications where energy conservation is required.

Optimal design of radial inflow turbine for ocean thermal energy conversion based on the installation angle of nozzle blade

Ocean Thermal Energy Conversion (OTEC), as a new type of renewable energy, has huge development potential. Turbine is the most critical component in the ocean thermal energy conversion system, which directly determines the performance and energy conversion efficiency of the system. Therefore, the optimal design of turbines is very important to improve the efficiency of ocean thermal energy conversion. Based on the full consideration of the small temperature difference application characteristics of ocean thermal energy conversion and the special thermophysical properties of organic working fluids, this paper designs an ammonia working centripetal turbine with a power of 100 kW for OTEC applications, and then analyzes the effect of different geometric parameters on turbine performance. At the same time, the key parameters of the turbine are optimized based on full three-dimensional CFD numerical simulation analysis. It's shown that the nozzle blade installation angle has a very important impact on the performance of the turbine. Through optimization, when the nozzle blade installation angle reaches 30.5°, the efficiency is 91.77%, which is 6.25% points higher than the design value. The internal flow field performance is the best without obvious shock wave and reverse vortex phenomenon, which further improves the efficiency of the turbine and improves the internal flow.

The thin film flow of Al2O3 nanofluid particle over an unsteady stretching surface

This work emphasizes the thermophysical properties of base fluid with different-shaped Al2O3 particles in the heat transfer of an unsteady thin film flow over a stretching layer. The study is performed under convective boundary conditions. A system of Partial Differential Equations (PDEs) is formed through detailed mathematical modeling. Using an appropriate set of similarity transformations, PDEs’ system is transformed into a set of nonlinear ordinary differential equations (ODE). The system of ordinary differential equations is solved in MATLAB using BVP4C. The graphical simulations analyze the impact of multi-shape Al2O3 nanoparticles and other physically significant related parameters such as Prandtl, Eckert and biot-numbers on the flow and heat transfer characteristics. In addition, the coefficient of skin friction and Nusselt number are measured and tabulated numerically for discussion. The study shows that Al2O3 nanoparticles have a high flow and heat transfer rate in a platelet form. Moreover, the temperature profile increases by growing the volume-fraction parameter and the biot-number, but the reverse pattern is found only for the slip parameter. The study is in excellent agreement with existing literature for a limited number of cases.

Some aspects of plate number estimation of plate heat exchangers (PHEs). A case study

Abstract For the proper estimation of the plate number (N) of a plate heat exchanger (PHE) – in addition to the flow rates and thermophysical properties of fluids –, an appropriate correlation is needed for convective heat transfer coefficient (α) calculation. When one does not have a criterial equation for the corresponding plate shape, we propose a selecting method for α. With the suggested relationships from literature, we calculate the plate number of a geometrically known, similar heat duty PHE and choose those relationships that give the same plate number with the known heat exchanger. In our case study, the plate number determined by any of the screened equations for whole milk preheating has almost the same value (n = 10 ± 1) regardless of the method used to solve the PHE model (plate efficiency and Nconverg or Kconverg convergence methods). For liquids’ thermophysical property estimation, we recommend averaging the values given by equations from literature, followed by equation fitting.

Experimental investigation on the effect of thermophysical properties of a heat transfer fluid on pumping performance for a convective heat transfer system

limited study that specifically discusses the relation between thermophysical properties of a Heat Transfer Fluid (HTF) and pumping performance. This study aims to find the effect of the change in thermophysical properties of HTF on the pumping performance, particularly for the delivery rate, slip factor coefficient, and volumetric efficiency. In this study, five different HTFs are used to assess the effect of working temperature and pumping speed on the pumping performance. Delivery rate is evaluated by setting the pumping speed from 0 to 1300 RPM where the working fluid temperature is set at 40, 140, and 200 °C. It shows that the HTF with a lower viscosity has a better delivery rate. The slip coefficient for all working fluid is ranging between 0.11–0.31 at temperature 200 °C. It is found that a higher working temperature for the fluid increases the slip coefficient and delivery rate. The volumetric efficiency is directly affected by the slip ranging from 69 – 89% at 200 °C. The heat transfer rate ranges from 40 – 98 °C for all fluids, which is mainly affected by the volumetric efficiency of the pump and also pumping speed where a higher pumping speed decreases the heat transfer rate. It can be concluded that the change in thermophysical properties of the working fluid will change the pumping performance. Therefore, it is important to adjust the pumping operation according to the temperature and properties of the working fluid to achieve the highest heat transfer rate for a convective heat transfer system.

A refined design method for precoolers with consideration of multi-parameter variations based on low-dimensional analysis

The precooler is a distinctive component of precooled air-breathing engines but constitutes a challenge to conventional thermal design methods. The latter are based upon assumptions that often reveal to be limited for precooler design. In this paper, a refined design method considering the variations of fluid thermophysical properties, flow area and thermal parameters distortion, was proposed to remediate their limitations. Firstly, the precooler was discretized into a fixed number of sub-microtubes based on a new discretization criterion. Next, in-house one-dimensional (1D) and two-dimensional (2D) segmented models were established for rapid thermal design and precooler rating with non-uniform airflow, respectively. The heat transfer experimental studies of supercritical hydrocarbon fuel were performed to verify the Jackson correlation for precooler design and the in-house models were validated against the reported data from open literature. On this basis, the proposed method was employed for the design analysis of hydrocarbon fuel precoolers for precooled-Turbine Based Combined Cycle (TBCC) engines. The results show that the local performance of precoolers is intrinsically impacted by the aforementioned three variations. In the case study, the local heat transfer performance is drastically affected by coolant flow transition. While the circumferential temperature distortion of airflow is weakened by heat transfer. With consideration of additional parameter variations, this novel method improves design accuracy and shortens the design time.

Numerical simulation of heat and mass transfer during heating and cooling parts of canned‐green‐olive pasteurization

AbstractSimultaneous modeling of heat and mass transfer was applied in a cylindrical geometry through computational fluid dynamic (CFD). Two‐dimensional equations of mass, momentum and energy conservation were solved using finite elements method. The meshes were 7,882 triangular elements where 1,056 of them were in boundaries. The simulation was solved for a metal can filled with olives (Conservolea CV) and a 6% acid‐brine. Constant thermophysical properties of fluid remained static over the processing period except for the viscosity (temperature dependent) and density (in buoyancy term). The comparison criteria, between the predicted and experimental figures, using to evaluate goodness of fit, namely the coefficient of correlation (r = .9933) and the root mean square error (RMSE = 3.6555) indicated that the model was valid. The warm‐low‐density fluid ascended through a thin boundary layer and exchanging the heat, at the top of the can, where it flowed downward through the pores between the olives. This natural convection displaced the Slowest Heating Zone (SHZ) towards the bottom of the can, and eventually stayed in a region that was about 10 ± 15% of the can height from the bottom. The inactivation time for the most‐heat‐resistant fungus (Monascus rubber) during the thermal processing of green olives at 100°C was 600 s based on SHZ. A comparison between heat transfer by conduction and conduction–convection showed that the rate of heat transfer in conduction–convection was much more than conduction, also the SHZ in conduction was displaced towards the top of the can.Practical ApplicationsComsol Multiphysic, was used in this research in order to predict temperature profile in olive pasteurized in a metal can so that the accurate location of cold point was evaluated and the process time can then be controlled to reduce overheating and nutritional reduction or under heating and safety problems. As the model was validated, all the model results would be accurate to use so that velocity pattern of the fluid was extracted and different assumptions of heat conduction also were considered. The importance of pasteurization in different industries and the significance of reducing energy consumption, reveal our research importance because the calculated‐process time was much lower than what is currently used in industry.

Comparative analysis of the efficiency of using hydrogen and steam methane reforming storage at combined cycle gas turbine for cogeneration

Combined cycle gas turbine cogeneration power plants provide maximal thermal efficiency. The facility thermal load depends upon ambient conditions and it may limit its unloading degree, or control range. Energy accumulation extends the control range by the energy storing during the power excess period and the energy discharge during the high consumption period. This paper considers two accumulation technologies, with the steam methane reforming and with hydrogen storage by using electrolyzer and fuel cell. In steam methane reforming technology a part of heat recovery steam generator steam passes to the synthetic gas production and reduces the electric power production during the low load periods. During the peak load periods, the synthetic gas is burned in combined cycle gas turbine and peak load gas turbine combustors. In hydrogen accumulation technology the excessive power produces hydrogen in an electrolyzer, which is stored and used during the peak load periods in fuel cells for additional electricity production. The simulation was carried out in the Aspen Plus software, the thermo-physical fluid properties were determined using the Peng-Robinson state equation. Application of the steam methane reforming accumulation technology increases the facility contribution margin by 2.6%, the hydrogen accumulation technology reduces this margin by 0.1%.

The IRC-PD Tool: A Code to Design Steam and Organic Waste Heat Recovery Units

The Algerian economy and electricity generation sector are strongly dependent on fossil fuels. Over 93% of Algerian exports are hydrocarbons, and approximately 90% of the generated electricity comes from natural gas power plants. However, Algeria is also a country with huge potential in terms of both renewable energy sources and industrial processes waste heat recovery. For these reasons, the government launched an ambitious program to foster renewable energy sources and industrial energy efficiency. In this context, steam and organic Rankine cycles could play a crucial role; however, there is a need for reliable and time-efficient optimization tools that take into account technical, economic, environmental, and safety aspects. For this purpose, the authors built a mathematical tool able to optimize both steam and organic Rankine units. The tool, called Improved Rankine Cycle Plant Designer, was developed in MATLAB environment, uses the Genetic Algorithm toolbox, acquires the fluids thermophysical properties from CoolProp and REFPROP databases, while the safety information is derived from the ASHRAE database. The tool, designed to support the development of both RES and industrial processes waste heat recovery, could perform single or multi-objective optimizations of the steam Rankine cycle layout and of a multiple set of organic Rankine cycle configurations, including the ones which adopt a water or an oil thermal loop. In the case of the ORC unit, the working fluid is selected among more than 120 pure fluids and their mixtures. The turbines’ design parameters and the adoption of a water- or an air-cooled condenser are also optimization results. To facilitate the plant layout and working fluid selection, the economic analysis is performed to better evaluate the plant economic feasibility after the thermodynamic optimization of the cycle. Considering the willingness of moving from a fossil to a RES-based economy, there is a need for adopting plants using low environmental impact working fluids. However, because ORC fluids are subjected to environmental and safety issues, as well as phase out, the code also computes the Total Equivalent Warming Impact, provides safety information using the ASHRAE database, and displays an alert if the organic substance is phased out or is going to be banned. To show the tool’s potentialities and improve the knowledge on waste heat recovery in bio-gas plants, the authors selected an in-operation facility in which the waste heat is released by a 1 MWel internal combustion engine as the test case. The optimization outcomes reveal that the technical, economic, environmental, and safety performance can be achieved adopting the organic Rankine cycle recuperative configuration. The unit, which adopts Benzene as working fluid, needs to be decoupled from the heat source by means of an oil thermal loop. This optimized solution guarantees to boost the electricity production of the bio-gas facility up to 15%.

Heat Transfer and Hydraulic Characteristics of Supercritical CO2 in Cooled and Heated Horizontal Semicircular Channels

Heat transfer characteristics of supercritical CO2 in horizontal semicircular channels are numerically investigated using Computational Fluid Dynamics method validated with experimental data. Comparison study is conducted for semicircular and circular channels with the same hydraulic diameter and boundary condition at the bulk temperature range including pseudocritical point. The results show that the heat transfer coefficients of the semicircular channel are significantly smaller than those of the circular channels due to the blocking effect at the corner area of the channel cross section, and the fluid thermophysical properties near the wall have a significant effect on the convective heat transfer performance in both heating and cooling cases. A modified model was proposed based on Olson correlation of the semicircular channel considering the channel geometry and near-wall fluid viscosity influence. Further study was conducted to discuss the effect of hydraulic diameter and boundary conditions on the heat transfer performance of the semicircular channel and indicate that the modified correlation shows a reasonable prediction of the heat transfer coefficients in the heated semicircular channel.

Proposed new equations for calculation of thermophysical properties of nanofluids

A trial-error procedure is applied for the derivation of correlations to estimate the relative thermal conductivity (kr) and dynamic viscosity (µr) of nanofluids using MATLAB. Thermophysical properties of particles and base fluids, particle diameter (dp), sphericity, capping layer thickness, Brownian motion of a particle, temperature, and volume fraction (φ) are considered. The accuracy of predicting kr and µr of nanofluids is developed using dimensionless parameters involving base fluid and particle characteristics. The results reveal that the estimated values are in a good agreement with the experimental data with a standard deviation of 2.16% and 8.16% for kr and µr of nanofluids, respectively. Besides that, 97.5% of the predicted kr values suit experimental data of kr with a mean deviation of ±5%, whereas 90.4% of the estimated µr values match the data of µr with a mean deviation of ±10%. Therefore, the proposed new equations will be useful for numerical simulation studies and the engineering design of heat transfer devices such as refrigeration systems, solar collectors, and heat exchangers.

Binary collisions of equal-sized water nanodroplets: Molecular dynamics simulations

Binary collision dynamics of equal-sized water nanodroplets are investigated numerically by using molecular dynamics (MD) simulations with a focus on the shape evolution and collision result of two colliding nanodroplets. The complete behavior of binary collisions is dynamically simulated using velocity-Verlet integrator in LAMMPS platform. Effects of several parameters such as impact velocity, dimensionless impact parameter (defined as the ratio of the off-center distance between the nanodroplets to the average diameter of two nanodroplets), liquid temperature and droplet size on binary collision outcomes are quantitatively studied. The simulations show that with the increasing of impact velocity, the outcome upon head-on binary collisions changes from coalescence to the fragmentation of the rim, and to disintegrates into many smaller nanodroplets. For impact parameter, the stretching separation is suppressed with the decrease of impact parameter. The controlling mechanism of stretching separation is basically related to the end-pinching mechanism dominated by high-inertia. For the higher liquid temperature, the liquid lamella caused by binary collisions leads to some tinier satellite nanodroplets because of the variations in thermophysical properties of fluid. The effect of larger nanodroplet diameter is found to enhance the deformation degree of head-on binary collisions. In addition, a We-B map map is established to qualitatively identify different regimes of binary collision. The present study provides some insight into the binary collision dynamics under micro-nano dimension for spraying engineering.

Semi-empirical and environmental assessment of the low GWP refrigerant HCFO-1224yd(Z) to replace HFC-245fa in high temperature heat pumps

Abstract This paper investigates a promising low-GWP refrigerant, HCFO-1224yd(Z), as an environmentally friendly replacement for HFC-245fa in high temperature heat pumps (HTHPs). First, the thermophysical properties of both fluids were analysed, and a single-stage cycle with Internal Heat Exchanger (IHX) was modelled. Then, a semi-empirical drop-in test replacement was assessed. The low-temperature reservoir was fixed at 80 °C, whereas the high-temperature reservoir was varied from 110 to 140 °C to cover a wide range of industrial applications. The theoretical and semi-empirical results illustrate that HCFO-1224yd(Z) heating capacity becomes around 8.9% lower than HFC-245fa. However, the higher suction density of HCFO-1224yd(Z) compared to the reference fluid can compensate for this effect, reducing the compressor power consumption. Hence, HCFO-1224yd(Z) presents a COP increase up to 4.5% compared to the reference fluid. At high-temperature reservoir of 140 °C, HCFO-1224yd(Z) shows a COP of 2.33, whereas HFC-245fa only reaches 2.23. The carbon footprint assessment illustrates a significant equivalent CO2,eq emissions reduction down to 90%, depending on the country (carbon emission factor). Therefore, HCFO-1224yd(Z) can be used as an alternative to HFC-245fa in HTHP systems due to its beneficial operating, energetic and environmental characteristics.

Design and analysis of nuclear and solar-based energy, food, fuel, and water production system for an indigenous community

For the sustainable communities, there is a strong need to address the United Nations' sustainable development goals for communities, cities and countries. In this paper, we develop a unique hybrid energy system for cleaner productions of energy, fuel, food and water for an indigenous community by addressing the following goals, namely: zero hunger; clean water; affordable and clean energy; industry, innovation and infrastructure; sustainable cities and communities; and climate action. Also, the present sustainable system is investigated thermodynamically by considering energy and exergy criteria and evaluated through energy and exergy efficiencies. As a case study, the Saugeen First Nation indigenous community in the Bruce Peninsula in Ontario, Canada, is selected for meeting the demands of useful commodities where an integration of a newly developed multigenerational system with an existing nuclear reactor is achieved in order to provide food security, supply the freshwater for drinking purposes, and meet the community's electricity and heat demands. Moreover, to exploit the existing thermophysical properties of fluids in the nuclear system, a hydrogen generation unit is proposed. The novel integration is enhanced the current nuclear system and increased the variety of useful outputs. The overall system is analyzed according to the first and second laws of thermodynamics. A transient (time-dependent) analysis is carried out via hourly simulations with software packages and hourly sensitive meteorological data. The overall system performance results are obtained as 65.8% for energy efficiency and 40.1% exergy efficiency at average ambient conditions for a 126.04 mol/s hydrogen production rate.

Bioconvection transport of Carreau nanofluid with magnetic dipole and nonlinear thermal radiation

BackgroundAn important area of research is the study of bioconvection effects on magnetic ferrofluid with nanoparticle suspension and motile microorganisms due to their wide range of applications. Magnetic nanostructures provide a direct influence on the magneto-viscous nature of ferrofluids resulting a considerable improvement in fluid viscosity and thermo-physical properties. Because of all the above-mentioned benefits, the development of a non-linear contamination effect on the magnetic dipole stretching stream is important. ObjectiveIn this work, Carreau nanomaterial is used for the composition of the flow in rheological relationships with bioconvection and Buongiorno's nanofluid model to analyze thermophoresis and Brownian motion characteristics. ApproachThe appropriate changes are employed to convert the PDEs into the ODEs. The popular bvp4c scheme (Labotto-IIIa formula) is being implemented to quantify the non-linear ordinary differential structures. ResultsThe influences of the variables are defined by graphical findings and numerical data. Our consequences depict that the microorganism field diminishes by growing approximations of Peclet number and bioconvection Lewis number. The impacts of Brownian motion and thermophoresis parameters on velocity and thermal profiles are studied in depth. The outcomes indicate that raising the Brownian motion and thermophoresis parameters raises the thermal profile.

Influence of Variable Properties on Quadratic Convective Flow of Casson Nanofluid Past an Inclined Plane

In this study, the combined effects of thermophysical fluid properties alongside nonlinear thermal and solutal convective processes in an inclined flow region containing Casson nanofluid subjected to slip and convective boundary conditions are considered. Application of induced non-uniform magnetic field strength applied perpendicular to the flow plane and the buoyancy influences are believed responsible for the quadratic convection rate. The prime PDEs are renewed to systems of ODEs via applicable transformations and similarity variables. Assuming a series trial solution, the flow distribution results were obtained numerically by collocation approach with Legendary polynomial basis function. Validation of the numerical results plays favorably when compared with the weighted residual method (Galerkin) and the existing literature. The results reveal that; Casson fluid exhibit a solid characteristic when yield stress is more than the shear stress, pronouncement of nonlinear solutal and thermal buoyancy effects predicts the acceleration of the flow fields greatly compared to the linear model, adherence between the fluid particles and flow surface displayed retardation in shear force thus enhanced the motion of Casson fluid and diminished the energy fields, surface suspension suppressesbthe flow but energizes both temperature and nanoparticle volume fraction profiles.

Физико-математическая модель и метод расчета процессов тепломассопереноса в системе пласт--горизонтальные скважины

In order to solve scientific and engineering problems arising during analysis and development of hard-to-recover hydrocarbon reserves in high-viscosity oil deposits, we performed a numerical study of heat and mass transfer processes in a mixture of water and oil. We achieved these goals by developing a hydrodynamic and thermophysical model of non-steady-state quasi-three-dimensional heat and mass transfer in a stratum featuring a system of horizontal wells. We propose an analytical approach to plotting a dynamic computational grid in a natural semi-fixed coordinate system. We compute streamlines and equipotential lines using the analytical solution proposed, which is based on complex analysis. The object of our investigation is natural strata saturatedby a multiphase fluid. We used the physical and mathematical model and the calculation method proposed to develop a software package and conduct a series of numerical and parametric studies concerning the effects caused by thermophysical properties of rocks and fluids combined with various operation modes in a system of horizontal wells. The paper describes how these parameters affect the rate of oil production in a real high-viscosity oil deposit. We verified the results obtained against actual core sample investigation data and technological parameters of oil deposit development, and further compared them to known analytical solutions and commercial hydrodynamic simulators

Thermal enhancement in hybrid nano-polymer using novel models for hybrid nanoparticles

Novel correlations for thermophysical properties of base fluid (micropolar fluid) and hybrid nanostructures are used to analyze the impact of the inclusion of copper oxide and titanium dioxide thermal enhancement in the polymer with microstructures. The polymers are assumed to be characterized by micropolar rheological equations. The models from governing laws are derived and are simplified by boundary approximations. The boundary conditions are based on no-slip. The finite element method (FEM) is used for numerical solutions. The mesh and convergence analysis are tested. The convergent solutions are further utilized for the simulation process. The wall shear and couple stresses are examined and the heat transfer rate is visualized. This study has predicted thermal optimization due to the simultaneous inclusion of copper oxide and titanium dioxide nanoparticles. The hybrid nanofluid is an efficient working fluid than the pure fluid. However, the presence of hybrid nanoparticles in micropolar fluid makes the viscous region wider. It is found that nano polymers with CuO experience less resistive force due to porous medium as compare to hybrid nanopolymers (CuO−TiO2−polymers). The angular motion slows down as the vortex viscosity parameter is increased. However, this decrease is more noticeable in hybrid nano-polymers than that in nanopolymers.

Heat transfer promotion in channel laminar flow employing a slab with slits and inclined ribs protruding across

PurposeThe purpose of this study is to promote laminar heat transfer from the channel heated through a slab with slits and inclined ribs protruding across.Design/methodology/approachThe novel design of this study is performed through making the slits in the slab (C1–C3: with slits; C4–C6: without slits) and changing the vertical location of this slab (1/4, 1/2 and 3/4 channel height). The thermal fluid characteristics of all cases are analyzed for various Reynolds numbers (500, 1,000, 1,500 and 2,000) by the SIMPLE-C algorithm.FindingsThe results display that the ribbed slab effectively improves the heat transfer. The slits can modify the flow field in the vortexes around the inclined ribs and remove more heat from this zone to promote the heat transfer. As compared with C0 (without a slab), C2 (the slab with slits and inclined ribs protruding across located vertically on the 3/4 channel height) raises the averaged Nusselt number up to 27.7% at Re = 2,000. As compared with C4 (without slits), C1 (with slits) gains the maximum increase in the averaged Nusselt number by 5.07% at Re = 1,000.Research limitations/implicationsThe constant thermo-physical properties of incompressible fluid and the steady flow are considered in this study.Practical implicationsThe numerical results will profit the design of heated passageway using a slab with slits and inclined ribs protruding across to acquire better heat transfer promotion.Originality/valueThis slab with slits and inclined ribs protruding across can be applied to the heat transfer promotion and thus be viewed as a useful cooling mechanism in the thermal engineering.

Experimental and numerical investigation of heat loss in transition modes of buried hot fuel oil pipeline

In this research, heat transfer of fuel oil flow through the buried pipeline in three regimes, turbulent, transition, and laminar conditions are investigated. A large-scale laboratory set-up is designed for this purpose and numerical modeling was also performed to study the effect of different parameters. The simulation is based on the fluid's thermophysical properties and the results are validated using experimental data. Due to the strong dependence of viscosity and density of fuel oil on the temperature, regime changes along the pipeline happens which complicate the calculation of friction factor. Using the experiment results and choosing different numerical methods, the acceptable model of friction factor in the transition zone for the experimental pipe and the real pipeline was achieved. Numerical simulation was performed on a 107 km pipeline using a powerful computer network to achieve the results. The approach which is used to simulate laminarization shows just a 3% discrepancy with experimental data. For the real pipeline, about 30 percent of the length is in transition mode from turbulent to laminar. The diameter of 26” is chosen as the most optimal size to transform 180000 barrels per day (BPD). According to the design thickness, diameter, and length of the pipeline, the maximum safe stop time (MSST) of the pipeline is 41 hours which is the most important data in the pipeline's maintenance period. Based on the present experimental data and simulation results, the optimal depth for the least heat loss from this pipeline is 0.9 to 2.7 meters.