Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2023Scopus SJRQ1A study on the combustion performance and NOx emissions characteristics of a novel U-type radiant tube based on MILD combustion theory
Fan, Huanbao; Feng, Junxiao; Bai, Wei; Wang, Hui; Akkurt, Nevzat; Li, Weidong; Gao, Jun; AliAkbaria, Omid; Xu, Qian
Based on the theory of moderate or intense low-oxygen dilution (MILD) combustion, a 3D steady-state CFD model coupling dual flue gas recirculation and dispersion combustion was developed to describe the flow field, combustion temperature field, wall temperature distribution, and NOx concentration field during the operation of a novel U-type radiant tube (N-URT). A user-defined function (UDF) method was implemented to simulate the dilution of O2 concentration in the combustion air due to external flue gas recirculation (E-FGR). The effects of the E-FGR ratio on combustion characteristics and NOx emission were evaluated. The simulated results were consistent with experimental results. The simulated NOx concentration at the outlet was reduced to 105.5 mg/m3 at 8% O2, which was about 35.2% lower than the conventional combustion method. The study found that when the E-FGR ratio was increased from 0 to 25%, the standard deviation of wall temperature decreased from 30.3 °C to 23.3 °C, and the non-uniformity coefficient decreased from 0.2598 to 0.2183, indicating an improvement in temperature uniformity. However, the thermal efficiency decreased from 82.1% to 76.2%. Moreover, at higher E-FGR ratios, the volume of the high-temperature region (above 1500 ℃) gradually decreased, and both the maximum flame temperature and the outlet NOx concentration decreased sharply. Regression equations for the E-FGR ratio (β) on the maximum combustion temperature (Tmax) and the outlet NOx concentration (CNOx) were obtained, and an E-FGR ratio greater than 13.4% was recommended to meet the emission requirements.
AtıfScopus14OpenAlex14
İncele - MakaleYalnız künye2023Scopus SJRQ2Physiological peristaltic flow of Jeffrey fluid inside an elliptic cross section with heat and mass transfer: Exact solutions through Polynomial solution technique
Nadeem, Sohail; Akhtar, Salman; Akkurt, Nevzat; Saleem, Anber; Almutairi, Shahah; Ghazwani, Hassan Ali
An interpretation of heat and mass transfer for the peristaltic flow of a non-Newtonian Jeffrey fluid inside a duct having an elliptic cross-section is mathematically investigated. We have considered constant heat absorption for the present study and a descriptive heat as well as mass transfer analysis is carried out. Exact solutions are computed by utilizing a polynomial solution technique to solve the dimensionless partial differential equations appearing in the problem. A purposeful and detailed graphical assessment is provided for the final mathematical results. Velocity as well as temperature profiles attain highest value at the core region of duct while these profiles gradually decline toward duct boundaries. The incrementing value of λ1 is resulting in an increase of flow and since λ1 is the dimensionless ratio of relaxation to retardation time, it means that the increasing value of λ1 results in an increase of relaxation time but it also results in decline of retardation time.
AtıfScopus11OpenAlex10İncele - MakaleAçık Erişim2023Scopus SJRQ2Investigation on application of plate-tube evaporative condensating technology for data centres in the northwest of China
Wu, Xueyuan; Shao, Shuangquan; Akkurt, Nevzat
The rapid development of data center leads to a rapid increase in energy consumption. In this paper, the plate and tube evaporative condenser is proposed for the water-cooled chiller and the data center cooling system to improve the energy efficiency in hot and dry summer and avoid icing in cold winter. The chiller can operate in the wet mode for compressor refrigeration and the dry mode for free cooling with the coefficient of performance (COP) of 5.2 in wet mode and up to 33.3 in dry mode. Furthermore, the system is applied in a data center in Ulumiqi, which is located in the dry and cold region and its ambient air temperature can vary from −32 °C to 45 °C throughout the year. The actual operation results show that the power usage effectiveness (PUE) value of the whole data centre is 1.349 in June, 1.229 in December, and 1.320 as the annual average, which is stable and efficient for five consecutive years. These results ensure the proposed system is an important technical solution for energy saving and emission reduction in data centres in cold regions.
AtıfScopus9WoS5OpenAlex8İncele - MakaleAçık Erişim2023Scopus SJRQ1A novel radial basis Bayesian regularization deep neural network for the Maxwell nanofluid applied on the Buongiorno model
Sabir, Zulqurnain; Akkurt, Nevzat; Ben Said, Salem
The aim of this work is to provide the numerical solutions of the fluid model by using the stochastic computing paradigms. The linear/exponential stretching sheets on magneto-rotating flow based on the Maxwell nanofluid have been provided using the Buongiorno model with the impacts of uneven heat source/sink, varying thermal conductivity and reactive species. The solutions of this transformed ordinary differential exponential stretching sheet model have been presented using a novel ‘radial basis’ (RB) activation function together with the Bayesian regularization deep neural network (BRDNN), i.e., RB-BRDNN. The deep neural network is presented into two hidden layers, while thirteen and twenty-five numbers of neurons have been used in the first and second layer. A reference dataset is proposed using the Runge-Kutta scheme for the model. The correctness of the stochastic RB-BRDNN procedure is examined through the comparison of proposed and database results, whereas minimal absolute error values provide the accuracy of the scheme. The reliability and competence of the computing RB-BRDNN solver is authenticated using the state transitions, correlation, regression, and error histograms.
AtıfScopus33WoS30OpenAlex36İncele - DüzeltmeYalnız künye2023Scopus SJRQ1Corrigendum to “A study on the combustion performance and NOx emissions characteristics of a novel U-type radiant tube based on MILD combustion theory” [Fuel 346 (2023) 128321] (Fuel (2023) 346, (S0016236123009341), (10.1016/j.fuel.2023.128321))
Fan, Huanbao; Feng, Junxiao; Bai, Wei; Wang, Hui; Akkurt, Nevzat; Li, Weidong; Gao, Jun; AliAkbaria, Omid; Xu, Qian
The authors regret to inform that Table 1 in the final (citable) version of our article [Fuel 346 (2023) 128321] published in Fuel has a serious error; some key data in Table 1 (page 4, Section 2.2) corresponded incorrectly to variables. This was mainly due to our carelessness and was not caught in time while reviewing proofs for our publications. The correction is necessary to improve the academic accuracy of the article and for ease of reference for the readers. We are therefore publishing this correction. Specifically, the pre-exponential factor Ar and activation energy Ea of 2CO + O2 → 2CO2 should be 2.239 × 1012 1/s and 1.7 × 108 J/kg·mol, respectively. The pre-exponential factor Ar and activation energy Ea of 2H2 + O2 → 2H2O should be 9.87 × 108 1/s and 3.1 × 107 J/kg·mol, respectively. Thank you for your understanding and the previous efforts of all the reviewers and editors. Reference [1] Huanbao Fan, Junxiao Feng, Wei Bai, Hui Wang, Nevzat Akkurt, Weidong Li, Jun Gao, Omid AliAkbaria, Qian Xu, A study on the combustion performance and NOx emissions characteristics of a novel U-type radiant tube based on MILD combustion theory, Fuel 346 (2023) 128321. DOI: https://doi.org/10.1016/j.fuel.2023.128321. The correct version of Table 1 is as follows: The authors would like to apologise for any inconvenience caused.
- MakaleYalnız künye2023Scopus SJRQ1Buoyancy-driven flow and thermal activity of nano-enhanced phase change material in inversed U-shaped chamber
Younis, Obai; Abderrahmane, Aissa; Laidoudi, Houssem; Akkurt, Nevzat; Fadhl, Bandar M.; Guedri, Kamel
This work aims to contribute to the positive evolution towards a green world and green energy by studying the natural convection of Nano-Enhanced Phase Change Material NEPCM in an inverted U-shaped cavity. The side walls of the cavity are kept at a cold temperature, while the upper corrugated wall and the lower wall are insulated with the expectation of the hot square body. The governing equations were solved numerically using the Galerkin finite element method (GFEM). The effects of the following factors on the heat transfer rate are presented and discussed: Rayleigh number (Ra = 103–106), number of ripples of the upper wall (N = 1–4), position of the square body (left, centre, and right), volume fraction of nanoparticles (ϕ = 0–0.08), and magnetic field strength (Ha = 0–100). It was found that the effect of N on the heat transfer rate was insignificant, while increasing ϕ reduced the heat transfer rate. In addition, placing the square body near the cold sidewalls (left or right position) improved the averaged Nusselt number (Nuavg), especially at low values of Ra. At the highest Ra studied, increasing Ha reduced the Nuavg by 15 %.
AtıfScopus11OpenAlex9İncele - MakaleYalnız künye2023Scopus SJRQ1Heat loss optimization and economic evaluation of a new fourth generation district heating triple pipe system
Chen, Xingli; Ren, Ling; Zheng, Qiang; Yang, Gang; Akkurt, Nevzat; Liu, Lin; Liu, Zhiwei; Qiang, Yujie; Yang, Huachao; Xu, Qian
In response to the heat loss caused by the temperature difference between the heating pipes and external environment during the pipe transportation, heat contradiction between the total heat loss of the piping system and heat transfer between tubes, as well as economic balance between the cost of heat loss and cost of material loss. Based on TOTS (Two-supply/One-return, triple pipe structure) heat loss theory of the fourth-generation district heating system, this paper optimizes structure of pipes by setting dimensionless characteristic parameters θ and β. Finally, a mathematical model is proposed to calculate economic efficiency of pipeline network by considering the cost of initial construction material loss and operation heat loss of the pipe. Results show that, from energy perspective, comprehensive heat as system energy consumption evaluation index is positively correlated with θ, decreases first and then increases as β increases. Total heat loss of system dominates comprehensive heat. Lowest comprehensive heat of system is 18.12 w/m for θ of 0.1945 and β of 0.0739. From economic perspective, total system loss cost as system economic evaluation index is positively correlated with both θ and β. Total system heat loss cost dominates total system loss cost. Lowest total system loss cost is $29.39/m for θ of 0.1945 and β of 0.0509.
AtıfScopus16OpenAlex20İncele - MakaleYalnız künye2023Scopus SJRQ1Latent heat thermal energy storage in a shell-tube design: Impact of metal foam inserts in the heat transfer fluid side
Ghalambaz, Mehdi; Sheremet, Mikhail; Raizah, Zehba; Akkurt, Nevzat; Ghalambaz, Mohammad
The improvement of heat transfer in latent heat thermal energy storage (LHTES) system is a crucial task. In the current study, the impact of diverse metal foam (MF) layer arrangements on heat transfer fluid (HTF) within a shell-tube LHTES is explored. Six distinct cases (A-F) with varied MF coverage percentages and layer dimensions were assessed. The local thermal non-equilibrium model was utilized to take into account the PCM and MF temperatures. The finite element method was used for solving the partial differential equations. The impact of MF configurations and inlet pressures (250 Pa, 500 Pa, and 750 Pa) on the thermal energy storage/release was addressed. Cases A-C, featuring a 50 % MF concentration, exhibit shorter melting times than Cases D–F, with decreasing MF concentrations. A higher MF concentration improves the melting process due to increased thermal conductivity and lower thermal resistance on the HTF side. Cases D–F, with a centralized MF layer and decreasing concentrations from 25 % to 6.25 %, display progressively shorter melting times, suggesting that a lower MF concentration leads to more efficient melting. Solidification times also decrease with increasing inlet pressures across all cases. Reynolds numbers, influenced by average HTF tube outlet velocity, vary substantially across cases and inlet pressure differences. Cases A-C demonstrate similar Reynolds numbers for each inlet pressure difference, while Cases D–F show a more pronounced increase in Reynolds numbers as the MF layer is reduced and flow resistance drops. Cases A (50 % MF layer) and F (6.5 % MF layer) provide the quickest charging and discharging times due to their unique combination of MF layer properties and inlet pressures. The study highlights the need to consider MF layer composition and inlet pressure when designing optimal LHTES systems for efficient energy storage/release.
AtıfScopus11WoS10OpenAlex11İncele - MakaleAçık Erişim2023Scopus SJRQ1Modeling and numerical simulation of non-Newtonian arterial blood flow for mild to severe stenosis
Nadeem, Sohail; Ali, Shahbaz; Akkurt, Nevzat; Ben Hamida, Mohamed Bechir; Almutairi, Shahah; Ali Ghazwani, Hassan; Eldin, Sayed M; Khan, Zareen A.; Al-Shafay, A.S.
The fundamental cause of coronary heart disease is thought to be atherosclerosis. Blood flow in arteries under plaque formation is widely studied using both experimental and theoretical methods in literature. This paper presents a comprehensive study on the mathematical modelling and numerical simulation of non-Newtonian blood flow in an idealized stenosed artery. Non-Newtonian behavior of blood flow is assumed by Casson and Quemada fluid models. An analysis is performed for four forms of stenosis, 50%, 60%, 70%, and 80%, which are defined by a narrowing of the artery's diameter. The mathematical model for non-Newtonian fluid transport is presented in the form of highly nonlinear coupled partial differential equations. A finite-volume approach is used to solve the system of equations numerically. The solutions are obtained using a hybrid mesh with hexahedron and tetrahedron control volumes. Numerical solutions are validated first with experimental results from the literature for a Newtonian fluid, and then the results are extended to non-Newtonian fluid models. It can be observed that the non-Newtonian nature of the fluid model influences flow dynamics and is a significant aspect to consider for arteries with small diameter. The velocity and pressure drop rise as the degree of stenosis develops. Wall shear is substantially larger in stenotic passages and severity of stenosis is directly related with this increasing behavior.
AtıfScopus32OpenAlex33İncele - MakaleAçık Erişim2023Scopus SJRQ1Case study of thermal and solutal aspects on non-Newtonian Prandtl hybrid nanofluid flowing via stretchable sheet: Multiple slip solution
Shamshuddin, MD.; Raizah, Zehba; Akkurt, Nevzat; Patil, Vishwambhar S.; Eldin, Sayed M.
The effect of multiple slip boundary conditions is one more important physical parameter on the flow investigation and have been studied in this analysis. Further, the effect of Ohmic heating and varying chemical reaction on non-Newtonian Prandtl hybrid nanofluid with water based nanofluids to an extending of leading edge was also investigated to this current analysis. An inclined magnetic field is introduced to fluid flow to regulate the fluid stream. Hybrid nanomaterial is synthesized by the dispersion of Cu and Cofe2O4 nanoparticles in Prandtl fluid. All chemical science specifications of nanofluid are measured as constant. Due to the nanofluid particles motion, the fluid concentration is inspected underneath chemical implications. A mathematical model is developed by assuming the flow as incompressible and purely cartesian coordinate system and appropriate non-dimensional variables are introduced for problem simplifications and dimensional analysis. The scheme for semi analytical study named Homotopy Analysis Method (HAM) is implied to get solutions to the equations. The procedure is then displayed pictorially where fluid velocity, temperature and concertation against various pertinent parameters are examined. It was found that, the Concentration field profiles have been shown to deteriorate because molecule diffusivity reduces as the chemical reaction parameter rises in both cases. In order to maintain thermal balance management in tiny heat density equipment and gadgets, current research may also be helpful in enhancing the thermal efficiency of heat exchangers.
AtıfScopus41WoS38OpenAlex44İncele - MakaleAçık Erişim2022The effect of using phase change materials and examining the aspect ratio in an air-cooled system of a plate battery connected to a solar system
Akkurt, Nevzat
Lithium-ion batteries are widely used in the electronics industry to store electrical energy. One of the challenges with these batteries is that they heat up during operation, which can damage the battery. For this reason, this paper simulates the cooling process of a plate-type (BTP) lithium-ion battery pack. To control the temperature of the battery (T-B), a laminar air flow and a phase change material (PCM) are used. The PCM is placed in a heat sink around the battery. This evaluation is performed temporarily for four different dimensions of the PCM pack. The hot outlet of this system is used to provide the thermal energy required for a small residential building (THE) at a mild temperature. The BTP was also simulated using COMSOL. The results show that the use of larger heat sinks can increase the maximum (MAX) and average (AVE) temperature of the battery. The minimum T-B occurs at different times for the smaller PCM heat sinks. Also, when using a heatsink with a larger PCM volume, it takes longer for the PCM to fully solidify. A BTP with 5 or 50 battery cells can provide up to 3% or 30% of the THE required for the building.
- MakaleYalnız künye2022Scopus SJRQ2Non-similar solutions and sensitivity analysis of nano-magnetic Eyring-Powell fluid flow over a circular cylinder with nonlinear convection
Basha, H. Thameem; Reddy, S. R. R.; Prasad, V. Ramachandra; Son, Kwon Joong; Ahammad, N. Ameer; Akkurt, Nevzat
AtıfOpenAlex15İncele - MakaleYalnız künye2022Scopus SJRQ1Dynamic response model and equivalent solution method of large-diameter buried energy transportation pipeline under moving load
Xu, Qian; Yang, Gang; Li, Zhuorui; Zou, Zhenwei; Zheng, Qiang; Zhong, Liqiong; Chen, Xingli; Akkurt, Nevzat; Du, Yanping; Xiong, Yaxuan
Long-distance energy pipeline pass under roads, subjecting them to repeated stress and posing pipeline safety problems. To simulate the effects of vehicles driving over energy transmission pipeline, this paper examines large-caliber buried pipelines in the suburbs. In this study, a mechanical action model of vehicle-soil-pipeline (VSP) interactions to transform the process of a vehicle driving into the dynamic process of a load changing with time in the specified area was created. The VSP model was used to analyze the influence of moving load and position on the structural characteristics of the pipeline section. An equivalent solution method with high precision and high calculation efficiency was proposed. The results showed that as the loading position approaches the pipeline or the load increases, the stress value at the top of the pipeline gradually exceeded the stress value at the bottom of the pipeline and became the area with the maximum stress value. The minimum stress location also changed from the lower half near the pipeline bottom (Point D-135°) to the upper half near the pipeline top (Point B-45°or Point H-315°). Using the polynomial fitting method, the stress values of the maximum points were equivalently converted. Under the premise of considering pipeline safety, the most suitable functional relationship for the moving load equivalent model was obtained.
AtıfScopus16OpenAlex13İncele - MakaleYalnız künye2022Scopus SJRQ1Numerical evaluation of the coupled/uncoupled effectiveness of a fluid-solid-thermal multi-field model for a long-distance energy transmission pipeline
Wang, Kang; Xie, Kai; Zhang, Hui; Qiang, Yujie; Du, Yanping; Xiong, Yaxuan; Zou, Zhenwei; Zhang, Mingbao; Zhong, Liqiong; Akkurt, Nevzat
As the main component of energy transmission, long-distance energy transmission pipeline (LETP), whose safety problem is becoming more and more prominent with the development of the oil and gas transportation industry, is susceptible to the traffic loading, temperature loading, pressure loading and other loadings. In this paper, the mechanical characteristics of LETP under the interaction of temperature loading and pressure loading are investigated. Based on the theory of multi-field coupling, the mathematical model of fluid-solid-thermal coupling of fluid-filled pipelines under the combined effect of temperature and pressure loadings is established and verified. Meanwhile, an equivalent model is proposed to accurately calculate the stress of any pipeline segment in LETP. The results show that the coupling of temperature loading and the pressure loading is significantly affected by the end-side constraints of the pipelines. For strong end-side constraint, the coupling effect of temperature and pressure loadings has a significant effect on the calculated equivalent stress. The difference between the stress solution under coupling effect and decoupling effect is above 30 MPa. However, for weak end-side constraints, the error is within 10 MPa. The equivalent stress can be approximated by the decoupling solution instead of the coupling solution.
AtıfScopus15OpenAlex15İncele - MakaleAçık Erişim2022Scopus SJRQ2Temperature-Dependent Density and Magnetohydrodynamic Effects on Mixed Convective Heat Transfer along Magnetized Heated Plate in Thermally Stratified Medium Using Keller Box Simulation
Ullah, Zia; Akkurt, Nevzat; Alrihieli, Haifaa F.; Eldin, Sayed M.; Alqahtani, Aisha M.; Hussanan, Abid; Ashraf, Muhammad; Jabeen, Mah
The heat transmission properties along the non-magnetized geometries have been numerically obtainedby various researchers. These mechanisms are less interesting in engineering and industrial processes because of excessive heating. According to current studies, the surface is magnetized and the fluid is electrically conductive, which helps to lessen excessive surface heating. The main objective of the current analysis is to numerically compute the temperature-dependent density effect on magnetohydrodynamic convective heat-transfer phenomena of electrical-conductive fluid flow along the vertical magnetized and heated plate placed in a thermally stratified medium. For the purpose of numerical analysis, the theoretical process governing heat and magnetic intensity along a vertical magnetic plate is examined. By using suitable and well-known similarity transformations for integration, the non-linear coupled PDEs for the aforementioned electrical-conductive fluid flow mechanism are changed and subsequently converted into non-similar formulation. The Keller Box method is used to numerically integrate the final non-similar equations. The MATLAB software program plots the transformed algebraic equations graphically and quantitatively. The behavior of the physical quantities such asvelocity graph, magnetic field graph, and temperature plot along with their slopes that arerate of skin friction, the rate of heat transfer, and the rate of magnetic intensity for different parameters included in the flow model. The novelty of the current work is to compute the magneto-thermo analysis of electrically conducting flow along the vertical symmetric heated plate. First, we secure the numerical solution for steady part and then these results are used to find skin friction, heat transfer, and magnetic intensity. In the current work, the fluid becomes electrically conducing due to a magnetized surface which insulates heat during the mechanism and reduces the excessive heating. The results are excellent and accurate because they are satisfied by its given boundary conditions. Additionally, the current problems have a big impact on the production of polymer materials, glass fiber, petroleum, plastic films, polymer sheets, heat exchangers, catalytic reactors, and electronic devices.
AtıfScopus20OpenAlex18İncele - MakaleYalnız künye2022Scopus SJRQ2Thermal analysis of a radiative nanofluid over a stretching/shrinking cylinder with viscous dissipation
Alqahtani, Aisha M.; Riaz Khan, M.; Akkurt, Nevzat; Puneeth, V.; Alhowaity, Awatif; Hamam, Haneen
This study explores the impact of thermal radiation and viscous dissipation on the stagnation point flow of a copper–water nanofluid across a convective stretching/shrinking cylinder. The copper suspension in the base fluid water enables the fluid to conduct more heat by increasing its thermal conductivity. The mathematical model that governs the flow of Cu-H2O nanofluid is formulated by the system of partial differential equations (PDEs) which are then subjected to transformation by introducing suitable similarity variables so the system is transformed to the Ordinary Differential Equations (ODEs). These equations have been solved numerically via the bvp4c package in MATLAB. The outcomes have been signified graphically in the form of heat transfer rate, temperature, skin friction and velocity which are dependent on the concerning flow parameters. For each of these result, dual solutions have been produced which are conditional on the shrinking of cylinder. These results declare that the skin friction increases for the shrinking cylinder and decreases for the stretching cylinder whereas an opposite trend is seen for the rate of heat transfer. Similarly, heat transfer is found to be decreasing for the increase in both Biot and Eckert number. Meanwhile, the existence of greater values of curvature parameter causes to enhance both first and second solution of velocity as well as the temperature is augmenting with the increase in Eckert number and volume fraction of nano particles.
AtıfScopus38OpenAlex39İncele - MakaleAçık Erişim2022Scopus SJRQ2Tangent hyperbolic non-Newtonian radiative bioconvection nanofluid flow from a bi-directional stretching surface with electro-magneto-hydrodynamic, Joule heating and modified diffusion effects
Prakash, J.; Tripathi, Dharmendra; Akkurt, Nevzat; Bég, O. Anwar
Motivated by bio-inspired nano-technological functional coating flows, in the current paper a theoretical study of laminar, steady, incompressible bioconvection flow of a tangential hyperbolic (non-Newtonian) nanofluid from a bi-directional stretching surface under mutually orthogonal electrical and magnetic fields is presented. Nonlinear thermal radiation, Joule heating and heat source/sink effects are included. Non-Fourier and non-Fickian models are also implemented which feature thermal and solutal relaxation. Buongiorno’s nanoscale model is adopted which features thermophoresis and Brownian motion effects. Rosseland’s model is employed for thermal radiation. The electro-viscous effects arising from the distortions of the double-capacitance electric flow field are addressed with a modified formulation of the Poisson–Boltzmann equation. Via appropriate similarity transformations, the coupled, nonlinear partial differential conservation boundary layer equations and wall and freestream boundary conditions are rendered into a nonlinear ordinary differential boundary value problem which is solved numerically with an efficient numerical Lobatto—IIIa collocation method available in the MATLAB bvp4c shooting solver. Validation with previous studies is included. Velocity is strongly damped with increasing buoyancy ratio and bioconvection Rayleigh number is generally greater with positive rather than negative electrical field parameter. Increasing the Eckert number reduces the density of motile microorganisms while raising the temperature. An increment in Brownian motion and radiative parameters strongly accentuates temperatures.
AtıfScopus36WoS33OpenAlex35İncele - MakaleYalnız künye2022Scopus SJRQ1Heat and mass transfer mechanism and control strategy of clean low carbon combustion technology in the novel-type coke oven flue with MILD combustion
Xu, Qian; Shen, Meng; Xie, Kai; Zhang, Hui; Akkurt, Nevzat; Wang, Jiulong; Xiong, Yaxuan; Shi, Kejian; Chen, Xingli; Lv, Qian
In the field of emission reduction, considering the limitations of single clean combustion technology and joint control of carbon emission, the application of Technology of Mixed-Gas (TMG), Technology of Low-calorific Value Gas (TLVG) and Technology of Low Oxygen Combustion (TLOC) in the Novel-type Coke Oven Flue with MILD Combustion (MILD-NCOF) was realized. By adjusting the ratio of coke oven gas to blast furnace gas (α), the ratio of flue gas to gas (β) and the ratio of flue gas to air (γ), the heat and mass transfer mechanism of combustion process in MILD-NCOF was researched, the dual emission control system and the regulation strategy of pollutant and carbon emissions were established. The results showed that with the increase of α, β and γ, the fluidity of gas and the reaction rate of combustible components in the fire path were improved, the heat and mass transfer was enhanced, and the effect of dual emission reduction of pollutants and carbon emissions was improved. When the mixing ratio α was 0.6, Tave was reached at 1594.93 K. The NOx concentration at the outlet was 116.34 mg/m3, and the sum of the molar concentrations of CO and CO2 at the outlet was reduced to 1.440 × 10−1. When the mixing ratio β was 2.4, Tave was reached at 1518.73 K, the NOx concentration at the outlet was 128.42 mg/m3, and the sum of the molar concentrations of CO and CO2 at the outlet was 1.127 × 10−1. When the mixing ratio γ was 0.6, Tave was reached at 1627.28 K, the NOx concentration at the outlet was 142.73 mg/m3, and the sum of the molar concentrations of CO and CO2 was reduced to 1.128 × 10−1, which could meet the dual standards of clean production and low-carbon environmental protection of MILD-NCOF.
AtıfScopus30OpenAlex36İncele - MakaleYalnız künye2022Scopus SJRQ1Heat transfer performance by forced convection of microencapsulated phase change material-latent functional thermal fluid flowing in a mini-channels heat sink
Xu, Qian; Zhu, Lidong; Yan, Xinyu; Yang, Jingbin; Wang, Zhaoxiao; Liu, DingHai; Yang, Gang; Chen, Xingli; Akkurt, Nevzat; Liu, Lin
Conventional single-phase coolants have not been able to meet the high cooling requirements of electronic devices. Microencapsulated phase change material-latent functional thermal fluid (MPCM-LFTF), a solid–liquid two-phase cooling medium, has the dual advantages of active liquid cooling and passive phase change material cooling. However, it also increases the power consumption in the mini-channels, and the cooling efficiency of MPCM-LFTF in practical applications needs to be further studied. A new MPCM-LFTF was prepared by paraffin melamine resin MPCM and base fluid (absolute ethanol and deionized water) in this work. The heat transfer performance and hydrodynamic properties were investigated using the dimensionless wall temperature and friction factor, respectively. The efficiency factor was introduced to evaluate the cooling efficiency of MPCM-LFTF in mini-channels. The experimental results showed that the addition of MPCM increased the viscosity of MPCM-LFTF, which increased the friction factor. MPCM-LFTF with a mass fraction of 15 % had the best effect of temperature control and reduced the dimensionless wall temperature by 40.5 %. However, considering the characteristics of flow resistance and improved heat transfer, MPCM-LFTF with a mass fraction of 10 % had the highest cooling efficiency and the efficiency factor was 57.0 % higher than that of the base fluid.
AtıfScopus35OpenAlex36İncele - MakaleAçık Erişim2022Scopus SJRQ1Free convective trickling over a porous medium of fractional nanofluid with MHD and heat source/sink
Lin, Yuanjian; Rehman, Sadique; Akkurt, Nevzat; Shedd, Tim; Kamran, Muhammad; Qureshi, Muhammad Imran; Botmart, Thongchai; Alharbi, Abdulaziz N.; Farooq, Aamir; Khan, Ilyas
Nanofluids are considered as smart fluids that can improve heat and mass transfer and have numerous applications in industry and engineering fields such as electronics, manufacturing, and biomedicine. For this reason, blood-based nanofluids with carbon nanotubes (CNTs) as nanoparticles in the presence of a magnetic field are discussed. The nanofluid traverses the porous medium. The nanofluids move on a vertical plate that can be moved. The free convection heat transfer mode is considered when the heat source and heat fluxes are constant. Convective flows are often used in engineering processes, especially in heat removal, such as geothermal and petroleum extraction, building construction, and so on. Heat transfer is used in chemical processing, power generation, automobile manufacturing, air conditioning, refrigeration, and computer technology, among others. Heat transfer fluids such as water, methanol, air and glycerine are used as heat exchange media because these fluids have low thermal conductivity compared to other metals. We have studied the effects of MHD on the heat and velocity of nanofluids keeping efficiency in mind. Laplace transform is used to solve the mathematical model. The velocity and temperature profiles of MHD flow with free convection of nanofluids were described using Nusselt number and skin friction coefficient. An accurate solution is obtained for both the velocity and temperature profiles. The graph shows the effects of the different parameters on the velocity and temperature profiles. The temperature profile improved with increasing estimates of the fraction parameter and the volume friction parameter. The velocity of the nanofluid is also a de-escalating function with the increasing values of the magnetic parameter and the porosity parameter. The thickness of the thermal boundary layer decreases with increasing values of the fractional parameter.
AtıfScopus13OpenAlex12
İncele
