TY - JOUR A1 - Yalçınkaya, Orhan A1 - Durmaz, Ufuk A1 - Tepe, Ahmet Ümit A1 - Benim, Ali Cemal A1 - Uysal, Ünal T1 - Heat and Flow Characteristics of Aerofoil-Shaped Fins on a Curved Target Surface in a Confined Channel for an Impinging Jet Array JF - Energies N2 - The main purpose of this investigation was to explore the heat transfer and flow characteristics of aero-foil-shaped fins combined with extended jet holes, specifically focusing on their feasibility in cooling turbine blades. In this study, a comprehensive investigation was carried out by applying impinging jet array cooling (IJAC) on a semi-circular curved surface, which was roughened using aerofoil-shaped fins. Numerical computations were conducted under three different Reynolds numbers (Re) ranging from 5000 to 25,000, while nozzle-to-target surface spacings (S/d) ranged from 0.5 to 8.0. Furthermore, an assessment was made of the impact of different fin arrangements, single-row (L1), double-row (L2), and triple-row (L3), on convective heat transfer. Detailed examinations were performed on area-averaged and local Nusselt (Nu) numbers, flow properties, and the thermal performance criterion (TPC) on finned and smooth target surfaces. The study’s results revealed that the use of aerofoil-shaped fins and the reduction in S/d, along with surface roughening, led to significant increases in the local and area-averaged Nu numbers compared to the conventional IJAC scheme. The most notable heat transfer enhancement was observed at S/d = 0.5 utilizing extended jets and the surface design incorporating aerofoil-shaped fins. Under these specific conditions, the maximum heat transfer enhancement reached 52.81%. Moreover, the investigation also demonstrated that the highest TPC on the finned surface was achieved when S/d = 2.0 for L2 at Re = 25,000, resulting in a TPC value of 1.12. Furthermore, reducing S/d and mounting aerofoil-shaped fins on the surface yielded a more uniform heat transfer distribution on the relevant surface than IJAC with a smooth surface, ensuring a relatively more uniform heat transfer distribution to minimize the risk of localized overheating. KW - Beschaufelung KW - Kühlung KW - aerofoil-shaped fin KW - impinging jet array KW - cooling of turbine blades KW - heat transfer uniformity KW - pin-fin row KW - Wärmeübertragung KW - Turbine Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-46387 SN - 1996-1073 VL - 17 IS - 5 PB - MDPI ER - TY - JOUR A1 - Shajahan, Mohamed Iqbal A1 - Benim, Ali Cemal T1 - Granular PCM based heat sink for electronics thermal management JF - Applied Thermal Engineering N2 - This study investigates aluminum heat sinks integrated with GR42 phase change material (PCM), aiming to enhance thermal inertia and stabilize device temperatures. This is important, since the increasing miniaturization and performance demands for electronic devices have led in a growing need for advanced thermal management systems capable of handling rapid transient loads. The novelty of the work lies in examining different heat sink layouts that optimize the heat dissipation capabilities of GR42 PCMs while minimizing size and weight for electronic cooling. The experimental testing was conducted using three configurations, namely no fin, circular fin and hexagonal fin, with three input powers (4 W, 8 W, and 12 W). The experimental results show that the hexagonal-fin heat sink, surface area is 25 % more than circular fins, exhibited superior thermal performance without significant variation in input power. Notably, the hexagonal-fin heat sink achieved the desired set point temperature of 55 ◦C in 33 % less time than the circular-fin design and 45 % less time than the heat sink without fins. Furthermore, the peak temperatures increased up to 21 % for circular fins. During the charging cycles, the enhancement ratios vary from 72 % and begin to narrow to 25 % during discharge cycles. The hexagonal-fin configuration also exhibited superior melting dynamics, completing the phase transition 44 % faster at higher input power than the circular fins, and established a thermal deviation of nearly 51 % less than finless heat sinks. These findings underscore the critical role of fin geometry and PCM integration in achieving uniform temperature distribution and improved energy storage efficiency. Overall, the hexagonal-fin heat sink with GR42 PCM shows strong potential as a passive cooling solution for low-power portable electronic devices. KW - Heat sinks KW - Portable electronic cooling KW - Latent heat storage KW - GR42 PCM KW - Hexagonal fin KW - Circular fin KW - HSD Publikationsfonds KW - DFG Publikationskosten Y1 - 2026 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-59649 SN - 1359-4311 VL - 286 PB - Elsevier ER - TY - JOUR A1 - Rückert, Frank Ulrich A1 - Ibrar, Burhan A1 - Ahmed, Arslan A1 - Allweyer, Benjamin A1 - Hübner, Dirk A1 - Klinger, Friedrich A1 - Knaus, Hermann A1 - Benim, Ali Cemal T1 - Fluid flow and heat transfer of a novel passive cooling system for gearless wind turbines with a power range of 3–12 MW JF - Energy N2 - Today, the gearless horizontal axis wind turbines are mainstream in wind energy industry. High demands of electric power led to bigger systems and active cooling reduces the overall efficiency of the turbines. Passive cooling systems have been examined for the first time for a gearless wind energy generator with power range of 3–12 MW. With further developed heat conductors, it is possible to operate a wind generator in a larger power class with passive cooling components. This is accompanied by enormous cost savings due to elimination of costs for active cooling elements such as the use of fans, pumps, and heat exchangers. An additional factor is the significant reduction in necessary maintenance due to the minimized incidence of corrosion and wear. Design of the cooling fins and an ideal position of the generator within the housing of the wind turbine has been objectives. Mandatory is that maximum temperatures of the generator fins should stay under 155 °C, which could be reached with several designs for different heat exchanger geometries. KW - Windturbine KW - Wärmeübertragung KW - Numerische Strömungssimulation KW - Generator KW - Kühlung KW - Passive cooling KW - Gearless wind turbine Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-46594 SN - 0360-5442 VL - 312 PB - Elsevier ER - TY - JOUR A1 - Benim, Ali Cemal T1 - Finite element solution of an enclosed turbulent diffusion flame JF - International Journal for Numerical Methods in Fluids N2 - A finite element formulation of enclosed turbulent diffusion flames is presented. A primitive variables approach is preferred in the analysis. A mixed interpolation is employed for the velocity and pressure. In the solution of the Navier‐Stokes equations, a segregated formulation is adopted, where the pressure discretization equation is obtained directly from the discretized continuity equation, considering the velocity‐pressure relationships in the discretized momentum equations. The state of turbulence is defined by a κ–ϵ model. Near solid boundaries, a wall function approach is employed. The combustion rates are estimated using the eddy dissipation concept. The expensive direct treatment of the integrodifferential equations of radiation is avoided by employing the moment method, which allows the derivation of an approximate local field equation for the radiation intensity. The proposed finite element model is verified by investigating a technical turbulent diffusion flame of semi‐industrial size, and comparing the results with experiments and finite difference predictions. KW - Finite-Elemente-Methode KW - Turbulente Diffusionsflamme KW - Navier-Stokes-Gleichung KW - Numerische Strömungssimulation Y1 - 1989 U6 - https://doi.org/10.1002/fld.1650090305 SN - 0271-2091 VL - 9 IS - 3 SP - 289 EP - 303 PB - Wiley ER - TY - JOUR A1 - Benim, Ali Cemal T1 - Finite element analysis of confined turbulent swirling flows JF - International Journal for Numerical Methods in Fluids N2 - The finite element method is applied to incompressible and statistically steady confined turbulent swirling flows. A velocity–pressure formulation is employed. The momentum and continuity equations are solved using a segregated algorithm. Two turbulence models, namely the standard κ–ε model and the algebraic stress model, are considered. It is shown that the algebraic stress model leads to significantly more accurate results in swirling flows compared to the κ–ε model. A novel way of implementing the algebraic stress model is presented in which the stresses are coupled to the Navier–Stokes equations in such a way that they ‘correct’ the effective viscosity hypothesis. This formulation seems to provide a convenient approach for finite elements. In deriving the discretization equations, a streamline‐upwind/Petrov–Galerkin method is employed. Comparisons performed between various upwind schemes show that the numerical solution may be substantially affected by the particular upwind procedure used. The analysis is extended to the prediction of particle motion in turbulent swirling flow fields. Here the fluid turbulence is modelled adopting a stochastic approach. The influence of turbulence modelling on particle movement is investigated. KW - Finite-Elemente-Methode KW - Turbulente Strömung KW - Navier-Stokes-Gleichung KW - Numerische Strömungssimulation Y1 - 1990 U6 - https://doi.org/10.1002/fld.1650110602 SN - 0271-2091 VL - 11 IS - 6 SP - 697 EP - 717 PB - Wiley ER - TY - JOUR A1 - Biswas, Nirmalendu A1 - Mandal, Dipak Kumar A1 - Bose, Sharmistha A1 - Manna, Nirmal K. A1 - Benim, Ali Cemal T1 - Experimental Treatment of Solar Chimney Power Plant — A Comprehensive Review JF - Energies N2 - Solar chimney power plants (SCPPs) are encouraging sustainable energy sources due to their low cost, abundance, low maintenance, and eco-friendliness. However, despite significant efforts to optimize SCPP design, their efficiency and power generation capabilities remain limited. Researchers have explored modifications in plant geometry and hybridization to improve efficiency. Despite extensive work in this area, commercialization of SCPPs has not yet been achieved. Most of the research is numerical and may differ from real-world practical use. The number of experimental studies is also relatively small. To facilitate commercialization, further investigation with practical and feasible dimensions is required. This comprehensive review paper aims to provide an in-depth analysis of experimental approaches and advancements in the field of SCPPs. The paper begins with an introduction, highlighting the background, significance, and objectives of the review. It provides an overview of the plants, discussing their principles and operation as innovative renewable energy systems. The historical development and evolution of solar chimneys are explored, shedding light on their progression over time. Case studies of operational hybrid SCPPs are examined to showcase real-world applications and performance. The paper also addresses environmental impacts and sustainability considerations associated with SCPPs. Furthermore, recommendations for future research and development in this field are provided to guide researchers and industry professionals. This study focuses on the possibility of commercialization of both standalone and hybrid SCPPs. KW - Erneuerbare Energien KW - Aufwindkraftwerk KW - Nachhaltigkeit KW - Zukunftserwartung KW - renewable energy KW - solar chimney power plant KW - SCPP KW - experimental KW - hybrid system KW - environmental impact KW - sustainability KW - challenges KW - future perspectives Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-46139 SN - 1996-1073 VL - 16 IS - 17 PB - MDPI ER - TY - JOUR A1 - Bhattacharyya, Suvanjan A1 - Benim, Ali Cemal A1 - Chattopadhyay, Himadri A1 - Banerjee, Arnab T1 - Experimental investigation of heat transfer performance of corrugated tube with spring tape inserts JF - Experimental Heat Transfer Y1 - 2019 U6 - https://doi.org/10.1080/08916152.2018.1531955 SN - 0891-6152 VL - 32 IS - 5 SP - 411 EP - 425 PB - Taylor & Francis ER - TY - JOUR A1 - Sulaiman, Mohammed A. A1 - Saber, Hindren Ali A1 - Hasan, Hasan F. A1 - Benim, Ali Cemal T1 - Experimental and numerical investigation of novel dew-point evaporative cooler with shell and tube design JF - Energy KW - Numerische Strömungssimulation KW - Kühlung Y1 - 2025 U6 - https://doi.org/10.1016/j.energy.2025.134686 SN - 0360-5442 VL - 317 PB - Elsevier ER - TY - INPR A1 - Sulaiman, Mohammed Abdulqader A1 - Saber, Hindren Ali A1 - Hasan, Hasan Fahmi A1 - Benim, Ali Cemal T1 - Experimental and Numerical Investigation of Novel Dew-Point Evaporative Cooler with Shell and Tube Design T2 - SSRN N2 - Implementing a neoteric practical design for dew-point evaporative cooler (DPEC) rather than the widely utilized flat plate and corrugated plate has been challenging since the first invention. Thus far, no study has been dedicated to design and experimentally implement a shell and tube concept for DPEC with an innovative configuration that can contribute in mass production, globalization, and effortless maintenance of such a high performance cooling machine. Therefore, in this paper, the shell and tube concept has been employed as a core design for DPEC that has been reinforced by a practical approaches. The practical approaches include a dedicated novel design for the proposed system and utilizing super cheap materials for the system’s construction. Both of the aforementioned approaches provide solutions for overcoming the aforementioned issues. In the meanwhile, the superiority of the proposed DPEC has been approved by comparing it to the flat plate DPEC. During the experimentations, the prototype was able to reduce the ambient temperature by up to 34.1°C (from 53°C to 18.9°C), besides, it could achieve a dew-point effectiveness of 99.6% and wet-bulb effectiveness of 135%. KW - Dew-point evaporative cooler KW - Tubular Maisotsenko cycle KW - Shell and tube design KW - Heat and mass diffusion KW - Numerische Strömungssimulation KW - Verdunstungskühlung Y1 - 2024 U6 - https://doi.org/10.2139/ssrn.4980477 PB - Elsevier ER - TY - JOUR A1 - Benim, Ali Cemal A1 - Escudier, Marcel A1 - Nahavandi, Ali A1 - Nickson, A. K. A1 - Syed, Khawar J. A1 - Joos, Franz T1 - Experimental and numerical investigation of isothermal flow in an idealized swirl combustor JF - International Journal of Numerical Methods for Heat & Fluid Flow Y1 - 2010 U6 - https://doi.org/10.1108/09615531011024084 VL - 20 IS - 3 SP - 348 EP - 370 PB - Emerald ER - TY - JOUR A1 - Iqbal, Sohail A1 - Benim, Ali Cemal A1 - Fischer, S. A1 - Joos, F. A1 - Kluβ, D. A1 - Wiedermann, Alexander T1 - Experimental and numerical analysis of natural bio and syngas swirl flames in a model gas turbine combustor JF - Journal of Thermal Science Y1 - 2016 U6 - https://doi.org/10.1007/s11630-016-0885-4 VL - 25 IS - 5 SP - 460 EP - 469 PB - Springer ER - TY - JOUR A1 - Mandal, Dipak Kumar A1 - Manna, Nirmal K. A1 - Biswas, Nirmalendu A1 - Rudra, Tansu A1 - Kumar, Rajesh A1 - Benim, Ali Cemal T1 - Enhanced heat transport in magneto-nanofluidic thermal systems: adiabatic block effects in grooved channels and ANN modeling JF - International Journal of Thermofluids N2 - This study investigates heat transfer enhancement in magneto-nanofluidic systems through the strategic placement of adiabatic blocks in grooved channels. Using CuO–H2O nanofluid in a bottom-heated channel with circular expansion, we examine the complex interactions between forced convection, magnetic fields, and uoyancy effects. Through systematic numerical analysis, we explore the combined influences of Rayleigh, Reynolds, and Hartmann numbers on thermal performance. Our findings reveal significant heat transfer enhancement (up to 137 %) under optimal conditions, particularly with vertical magnetic field orientation at Re = 100 and Ha = 30. The results demonstrate how adiabatic blocks modify flow structures, with larger blocks diminishing vortex intensity while elevated Ra generates secondary vortices that interact with primary circulations. Magnetic field effects show notable dependence on orientation, with vertical fields generally promoting better heat transfer than horizontal configurations. To complement the numerical analysis, we develop a predictive model using Artificial Neural Network (ANN) for Nusselt numbers across various operating conditions, achieving over 99 % accuracy. The integrated computational-ANN approach offers significant advancements in optimizing thermal systems in various areas, ranging from electronics cooling to microfluidic devices. KW - Mixed convective flow KW - Nanofluids KW - Heat transfer augmentation KW - Adiabatic block KW - Grooved channel KW - Neural network KW - HSD Publikationsfonds Y1 - 2026 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-60127 SN - 2666-2027 VL - 31 PB - Elsevier ER - TY - JOUR A1 - Biswas, Nirmalendu A1 - Mandal, Dipak Kumar A1 - Manna, Nirmal K. A1 - Benim, Ali Cemal T1 - Enhanced energy and mass transport dynamics in a thermo-magneto-bioconvective porous system containing oxytactic bacteria and nanoparticles: cleaner energy application JF - Energy Y1 - 2023 U6 - https://doi.org/10.1016/j.energy.2022.125775 SN - 0360-5442 VL - 263 IS - B PB - Elsevier ER - TY - JOUR A1 - Bhattacharyya, Suvanjan A1 - Bhatt, Tapasvi A1 - Vishwakarma, Devendra Kumar A1 - Benim, Ali Cemal A1 - Abraham, John T1 - Effect of mechanical vibration and its influence on thermal performance of a nanofluid heat exchanger JF - Numerical Heat Transfer: An International Journal of Computation and Methodology, Part A: Applications KW - Numerische Strömungssimulation KW - Mechanische Schwingung KW - Wärmeaustauscher Y1 - 2024 U6 - https://doi.org/10.1080/10407782.2024.2331589 SN - 1040-7782 SP - 1 EP - 24 PB - Informa ER - TY - JOUR A1 - Xia, Jiliang A1 - Smith, Brian L. A1 - Benim, Ali Cemal A1 - Schmidli, Jiirg A1 - Yadigaroglu, George T1 - Effect of inlet and outlet boundary conditions on swirling flows JF - Computers & Fluids KW - Numerische Strömungssimulation KW - Wirbelströmung Y1 - 1997 U6 - https://doi.org/10.1016/S0045-7930(97)00026-1 SN - 0045-7930 VL - 26 IS - 8 SP - 811 EP - 823 PB - Elsevier ER - TY - JOUR A1 - Aich, Rishav A1 - Barghavi, Devarakonda A1 - Benim, Ali Cemal T1 - Effect of hydrodynamic and thermal anisotropy on convective heat transfer in a fluid saturated porous duct: A finite volume approach JF - Numerical Heat Transfer: An International Journal of Computation and Methodology, Part A: Applications KW - Numerische Strömungssimulation KW - Konvektion KW - Anisotropie Y1 - 2025 U6 - https://doi.org/10.1080/10407782.2025.2527971 SN - 1521-0634 PB - Taylor & Francis ER - TY - JOUR A1 - Başaran, Anıl A1 - Benim, Ali Cemal T1 - Development of Correlations Based on CFD Study for Microchannel Condensation Flow of Environmentally Friendly Hydrocarbon Refrigerants JF - Energies N2 - A CFD simulation of the condensation flow of R600a and R290 within microchannels was conducted to explore the effect of mass flux, hydraulic diameter, and vapour quality on heat transfer rate and pressure drop. Data obtained from CFD simulations were used to develop new heat transfer and pressure drop correlations for the condensation flows of R600a and R290, which are climate-friendly refrigerants. Steady-state numerical simulations of condensation flow of refrigerants were carried out inside a single circular microchannel with diameters varying between 0.2 and 0.6 mm. The volume of fluid approach was used in the proposed model, calculating the interface phase change using the Lee model. The CFD simulation model was validated via a comparison of the simulation results with the experimental data available in the literature. It is found that the newly developed Nu number correlation shows a deviation, with an Ave-MAE of 11.16%, compared to those obtained by CFD simulation. Similarly, the deviation between friction factors obtained by the newly proposed correlation and those obtained by CFD simulation is 20.81% Ave-MAE. Widely recognized correlations that are applicable to the condensation of refrigerants within small-scale channels were also evaluated by comparing newly developed correlations. It is concluded that the newly proposed correlation has a higher accuracy in predicting the heat transfer coefficient and pressure drop. This situation can contribute to the creation of a sustainable system via the use of microchannels and climate-friendly refrigerants, like R600a and R290. KW - Druckabfall KW - Numerische Strömungssimulation KW - Kältemittel KW - condensation flow KW - heat transfer coefficient KW - pressure drop KW - microchannel KW - CFD simulation KW - climate-friendly refrigerants KW - hydrocarbon refrigerants Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-46398 SN - 1996-1073 VL - 17 IS - 7 PB - MDPI ER - TY - JOUR A1 - Ebling, Dirk A1 - Krumm, A. A1 - Pfeiffelmann, Björn A1 - Gottschald, J. A1 - Bruchmann, J. A1 - Benim, Ali Cemal A1 - Adam, Mario A1 - Labs, R. A1 - Herbertz, R. R. A1 - Stunz, A. T1 - Development of a System for Thermoelectric Heat Recovery from Stationary Industrial Processes JF - Journal of Electronic Materials KW - heat recovery KW - Thermoelectric generation KW - thermoelectric generation system KW - waste heat KW - EnerTEG Y1 - 2016 U6 - https://doi.org/10.1007/s11664-016-4511-8 N1 - The authors acknowledge financial support from the Ministry of Economic Affairs and Energy of the State of North Rhine-Westphalia, Germany and the European Commission from the European Regional Development Fund. VL - 45 IS - 7 SP - 3433 EP - 3439 PB - Springer ER - TY - CHAP A1 - Rückert, Frank Ulrich A1 - Burhan, Ibrar A1 - Ahmed, Arslan A1 - Hübner, Dirk A1 - Allweyer, Benjamin A1 - Klinger, Friedrich A1 - Benim, Ali Cemal T1 - Development of a Passive Cooling System for a Gearless Wind Energy Generator T2 - Advances in Computational Heat and Mass Transfer Proceedings of the 14th International Conference on Computational Heat and Mass Transfer (ICCHMT 2023), 4-8 September, 2023, Düsseldorf, Germany KW - Numerische Strömungssimulation KW - Windenergie KW - Windturbine KW - Kühlung KW - Wärmeaustauscher Y1 - 2024 SN - 9783031672408 U6 - https://doi.org/10.1007/978-3-031-67241-5_30 SN - 2195-4356 VL - 1 SP - 333 EP - 343 PB - Springer Nature CY - Cham ER - TY - JOUR A1 - Başaran, Anıl A1 - Benim, Ali Cemal T1 - Condensation Flow of Refrigerants Inside Mini and Microchannels: A Review JF - Applied Sciences N2 - Nowadays, the demand for obtaining high heat flux values in small volumes has increased with the development of technology. Condensing flow inside mini- and microchannels has been becoming a promising solution for refrigeration, HVAC, air-conditioning, heat pumps, heat pipes, and electronic cooling applications. In these applications, employing mini/microchannels in the condenser design results in the working fluid, generally refrigerant, undergoing a phase change inside the mini/microchannels. On the other hand, the reduction in the hydraulic diameter during condensation gives rise to different flow regimes and heat transfer mechanisms in the mini- and microchannels compared to the conventional channels. Therefore, the understanding of fluid flow and heat transfer characteristics during condensation of refrigerant inside mini- and microchannels has been gaining importance in terms of condenser design. This study presents a state-of-the-art review of condensation studies on refrigerants inside mini- and microchannels. The review includes experimental studies as well as correlation models, which are developed to predict condensation heat transfer coefficients and pressure drop. The refrigerant type, thermodynamical performance, and compatibility, as well as the environmental effects of refrigerant, play a decisive role in the design of refrigeration systems. Therefore, the environmental impacts of refrigerants and current regulations against them are also discussed in the present review. KW - Kondensation KW - Druckabfall KW - Kältemittel KW - condensation KW - microchannels KW - minichannels KW - heat transfer coefficient KW - pressure drop KW - refrigerants KW - Wärmeübergangszahl Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-46358 SN - 2076-3417 VL - 14 IS - 7 PB - MDPI ER - TY - JOUR A1 - Benim, Ali Cemal A1 - Ozkan, K. A1 - Cagan, M. A1 - Gunes, D. T1 - Computational investigation of turbulent jet impinging onto rotating disk JF - International Journal of Numerical Methods for Heat & Fluid Flow Y1 - 2007 U6 - https://doi.org/10.1108/09615530710730157 VL - 17 IS - 3 SP - 284 EP - 301 PB - Emerald ER - TY - JOUR A1 - Benim, Ali Cemal A1 - Brillert, Dieter A1 - Cagan, Markos T1 - Computational investigation of the flow in pre-swirl stator-rotor systems JF - International Journal of Computational Methods N2 - A 3D computational analysis has been applied to investigate direct transfer, pre-swirl systems for gas turbine cooling. Alternative computational procedures have been applied and results have been compared with measurements. Based on these validation studies, strategies for modeling such systems have been proposed. Present results suggest that sufficiently accurate predictions can be obtained using a quasi-steady analysis applying the "frozen rotor" approach for treating the interface between the stationary and rotating domains. KW - Gasturbine KW - Kühlung KW - Numerische Strömungssimulation Y1 - 2004 U6 - https://doi.org/10.1142/S0219876204000125 SN - 0219-8762 VL - 1 IS - 2 SP - 329 EP - 343 PB - World Scientific ER - TY - JOUR A1 - Benim, Ali Cemal A1 - Canal, Cansu Deniz A1 - Boke, Yakup Erhan T1 - Computational investigation of oxy-combustion of pulverized coal and biomass in a swirl burner JF - Energy Y1 - 2022 U6 - https://doi.org/10.1016/j.energy.2021.121852 SN - 0360-5442 VL - 238 IS - C PB - Elsevier ER - TY - JOUR A1 - Benim, Ali Cemal A1 - Korucu, Ayse T1 - Computational investigation of non-premixed hydrogen-air laminar flames JF - International Journal of Hydrogen Energy KW - Wasserstoff KW - Laminare Strömung KW - Reaktionsmechanismus KW - Stickstoffoxide KW - Hydrogen combustion KW - Non-premixed combustion KW - Laminar flames KW - Reaction mechanisms KW - Nitrogen oxide formation Y1 - 2023 U6 - https://doi.org/10.1016/j.ijhydene.2022.12.248 SN - 0360-3199 VL - 48 IS - 38 SP - 14492 EP - 14510 PB - Elsevier ER - TY - JOUR A1 - Pfeiffelmann, Björn A1 - Benim, Ali Cemal A1 - Joos, Franz T1 - Computational Investigation of Impingement Cooling of Thermoelectric Generators JF - Heat Transfer Engineering Y1 - 2021 U6 - https://doi.org/10.1080/01457632.2019.1699296 SN - 0145-7632 VL - 42 IS - 3-4 SP - 282 EP - 295 PB - Taylor & Francis ER - TY - JOUR A1 - Benim, Ali Cemal A1 - Frank, Thiemo A1 - Assmann, Alexander A1 - Lichtenberg, Artur A1 - Akhyari, Payam T1 - Computational investigation of hemodynamics in hardshell venous reservoirs: A comparative study JF - Artificial Organs N2 - Extracorporeal circulation using heart‐lung‐machines is associated with a profound activation of corpuscular and plasmatic components of circulating blood, which can also lead to deleterious events such as systemic inflammatory response and hemolysis. Individual components used to install the extracorporeal circulation have an impact on the level of activation, most predominantly membrane oxygenators and hardshell venous reservoirs as used in extracorporeal systems. The blood flows in two different hardshell reservoirs are computationally investigated. A special emphasis is placed on the prediction of an onset of transition and turbulence generation. Reynolds‐averaged numerical simulations (RANS) based on a transitional turbulence model, as well as large eddy simulations (LES) are applied to achieve an accurate prediction. In the LES analysis, the non‐Newtonian behavior of the blood is considered via the Carreau model. Blood damage potential is quantified applying the Modified Index of Hemolysis (MIH) based on the predicted flow fields. The results indicate that the flows in both reservoirs remain predominantly laminar. For one of the reservoirs, considerable turbulence generation is observed near the exit site, caused by the specific design for the connection with the drainage tube. This difference causes the MIH of this reservoir to be nearly twice as large as compared to the alternative design. However, a substantial improvement of these performance criteria can be expected by a local geometry modification. Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-29070 SN - 1525-1594 VL - 44 IS - 4 SP - 411 EP - 418 PB - Wiley ER - TY - JOUR A1 - Bhattacharyya, Suvanjan A1 - Chattopadhyay, Himadri A1 - Benim, Ali Cemal T1 - Computational investigation of heat transfer enhancement by alternating inclined ribs in tubular heat exchanger JF - Progress in Computational Fluid Dynamics KW - CFD KW - forced convection KW - transitional turbulence KW - inclined ribs KW - heat transfer enhancement Y1 - 2017 U6 - https://doi.org/10.1504/PCFD.2017.088818 SN - 1468-4349 VL - 17 IS - 6 SP - 390 EP - 396 PB - Inderscience Enterprises Limited ER - TY - JOUR A1 - Benim, Ali Cemal A1 - Pfeiffelmann, Björn A1 - Ocłoń, Paweł A1 - Taler, Jan T1 - Computational investigation of a lifted hydrogen flame with LES and FGM JF - Energy Y1 - 2019 U6 - https://doi.org/10.1016/j.energy.2019.02.133 SN - 0360-5442 VL - 173 SP - 1172 EP - 1181 PB - Elsevier ER - TY - JOUR A1 - Ali, Ramzan A1 - Farooq, A. A1 - Shahzad, A. A1 - Benim, Ali Cemal A1 - Iqbal, A. A1 - Razzaq, M. T1 - Computational approach on three-dimensional flow of couple-stress fluid with convective boundary conditions JF - Physica A: Statistical Mechanics and its Applications Y1 - 2022 U6 - https://doi.org/10.1016/j.physa.2019.124056 SN - 0378-4371 VL - 553 PB - Elsevier ER - TY - JOUR A1 - Benim, Ali Cemal A1 - Diederich, Michael A1 - Gül, Fethi A1 - Oclon, Pawel A1 - Taler, Jan T1 - Computational and experimental investigation of the aerodynamics and aeroacoustics of a small wind turbine with quasi-3D optimization JF - Energy Conversion and Management Y1 - 2018 U6 - https://doi.org/10.1016/j.enconman.2018.09.042 VL - 177 SP - 143 EP - 149 PB - Elsevier ER - TY - CHAP A1 - Özman, Cansu A1 - Gül, Fethi A1 - Diederich, Michael A1 - Benim, Ali Cemal A1 - Janoske, Uwe T1 - Computational and Experimental Investigation of Flow and Convective Heat Transfer along Rough Surfaces T2 - Proceedings of CONV-22: Int. Symp. on Convective Heat and Mass Transfer June 5 – 10, 2022, Turkey KW - Numerische Strömungssimulation KW - Wärmeübertragung KW - Rauigkeit KW - Turbulenzmodell Y1 - 2022 U6 - https://doi.org/10.1615/ICHMT.2022.CONV22.590 SP - 447 EP - 454 PB - Begellhouse ER - TY - JOUR A1 - Pfeiffelmann, Björn A1 - Diederich, Michael A1 - Gül, Fethi A1 - Benim, Ali Cemal A1 - Heese, Markus A1 - Hamberger, Andreas T1 - Computational and Experimental Investigation of an Industrial Biomass Furnace JF - Chemical Engineering & Technology Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-27747 SN - 1521-4125 VL - 43 IS - 8 SP - 1538 EP - 1546 PB - Wiley ER - TY - JOUR A1 - Benim, Ali Cemal A1 - Cagan, Markos A1 - Günes, Dogan T1 - Computational analysis of transient heat transfer in turbulent pipe flow JF - International Journal of Thermal Sciences KW - Turbulenzmodell KW - Wärmeübertragung KW - Numerische Strömungssimulation KW - Turbulente Strömung Y1 - 2004 U6 - https://doi.org/https://doi.org/10.1016/j.ijthermalsci.2004.02.012 SN - 1290-0729 VL - 43 IS - 8 SP - 725 EP - 732 PB - Elsevier ER - TY - JOUR A1 - Deniz Canal, Cansu A1 - Boke, Yakup Erhan A1 - Aydin, Ozer A1 - Benim, Ali Cemal T1 - COMPUTATIONAL ANALYSIS OF PULVERIZED COAL CO-FIRING WITH BIOMASS IN 150MWe UNIT OF TUNCBILEK THERMAL POWER PLANT JF - Isi Bilimi ve Teknigi Dergisi - Journal of Thermal Science and Technology Y1 - 2021 U6 - https://doi.org/10.47480/isibted.979314 SN - 1300-3615 VL - 41 IS - 1 SP - 37 EP - 50 PB - Turkish Society for Thermal Sciences & Technology ER - TY - JOUR A1 - Benim, Ali Cemal A1 - Escudier, M. P. A1 - Nahavandi, A. A1 - Nickson, A. K. A1 - Syed, Khawar J. A1 - Joos, F. T1 - Computational analysis of incompressible turbulent flow in an idealised swirl combustor JF - Progess in Computational Fluid Dynamics, An International Journal Y1 - 2011 U6 - https://doi.org/10.1504/pcfd.2011.037571 VL - 11 IS - 1 SP - 42 EP - 45 PB - inderscience ER - TY - JOUR A1 - S, Kasiviswanathan A1 - Shajahan, Mohamed Iqbal A1 - R, Bharathiraja A1 - Murali, Arun Prasad A1 - Benim, Ali Cemal T1 - Comprehensive overview of phase change materials in electronics, building, and solar applications JF - Engineering Research Express N2 - Phase change materials (PCMs) are a viable way to improve energy efficiency and thermal control in a variety of sectors. With an emphasis on their function in thermal control, this review article offers an in-depth review of PCM applications in electronics, buildings and solar energy systems. PCMs are used in electronics to control device temperatures, which lowers the risk of overheating and increases operational efficiency by 10% to 25%. Through latent heat storage and release in reaction to temperature changes, PCMs are incorporated into walls, floors, and roofs in building applications to improve thermal comfort and cut energy use by 15% to 30%. By storing thermal energy for steady power generation, PCMs increase the dependability and efficiency of solar energy systems by 8%–20%. This review examines the basic ideas behind PCMs, assesses various PCM (such as organic, inorganic, and eutectic PCMs), and details about real-world applications in these energy management fields. Important issues are examined, such as material compatibility, cost-effectiveness, and long-term stability. In order to maximize performance in these crucial applications, the conclusion emphasizes the need for improvements in cost-effective PCM formulations for the improved thermal conductivity (0.2–0.7 W m−1·K−1), and adaptive control systems. KW - Energieeffizienz KW - Temperaturregelung KW - Elektronik KW - Latentwärmespeicher KW - Sonnenenergie Y1 - 2026 U6 - https://doi.org/10.1088/2631-8695/ae342a SN - 2631-8695 VL - 8 IS - 3 PB - IOP Publishing ER - TY - JOUR A1 - Benim, Ali Cemal A1 - Pfeiffelmann, Björn T1 - Comparison of Combustion Models for Lifted Hydrogen Flames within RANS Framework JF - Energies KW - DOAJ Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-27727 SN - 1996-1073 VL - 13 IS - 1 PB - MDPI ER - TY - JOUR A1 - Benim, Ali Cemal A1 - Çiçek, Aydın T1 - Comparative analysis of water and carbon dioxide injection for the thermohydraulics of an EGS project in Dikili Geothermal Field, Türkiye JF - Bulletin Of The Mineral Research and Exploration N2 - A comparative numerical analysis of the thermohydraulics of an enhanced geothermal system (EGS) project in Türkiye in Dikili area is presented. The fractured granodiorite is modelled as porous media, utilizing the numerically suggested data of other authors for the corresponding hydraulic characteristics. As the heat transmission fluid, two different mediums are alternatively considered. These are the more classical medium, water and the supercritical Carbon Dioxide (sCO2). Transient calculations are performed for a time period of twenty years, comparing the temporally developing results obtained for water and sCO2 with each other. Based on modeling parameters and assumptions, higher production temperatures are observed with sCO2, in comparison to water, implying an advantage for sCO2 usage as a working fluid in EGS. This is accompanied by the further advantage of a lower pressure drop for sCO2. On the other hand, the temperature advantage is relativized by the lower specific heat capacity of sCO2 causing a decrease in the production thermal power. In general, the present re found to be encouraging for a further and more detailed analysis of the employment of sCO2 as working fluid in EGS. KW - Numerische Strömungssimulation KW - Thermohydraulik KW - Geothermik KW - Dikili Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-49115 SN - 0026-4563 VL - 171 SP - 91 EP - 105 PB - Maden Tetkik ve Arama Genel Müdürlüğü ER - TY - JOUR A1 - Zengin, İbrahim A1 - Erdoğan, Beytullah A1 - Benim, Ali Cemal T1 - CFD and Taguchi based optimization of air driven single stage partial admission axial turbine blade profiles JF - Energy KW - Taguchi-Methode KW - Numerische Strömungssimulation KW - Axialturbine KW - Beschaufelung KW - Optimierung KW - Impulse turbine KW - Partial-admission Y1 - 2024 U6 - https://doi.org/10.1016/j.energy.2024.130333 SN - 0360-5442 VL - 290 PB - Elsevier ER - TY - JOUR A1 - Epple, Bernd A1 - Fiveland, Woody A1 - Krohmer, Bernd A1 - Richards, Galen A1 - Benim, Ali Cemal T1 - Assessment of two-phase flow models for the simulation of pulverized coald combustion JF - Clean Air: International Journal on Energy for a Clean Environment KW - Numerische Strömungssimulation KW - Kohle KW - Verbrennung KW - Zweiphasenströmung Y1 - 2005 U6 - https://doi.org/10.1615/InterJEnerCleanEnv.v6.i3.50 SN - 1561-4417 VL - 6 IS - 3 SP - 267 EP - 287 PB - Begell House ER - TY - JOUR A1 - Pfeiffelmann, Bjorn A1 - Ozman, Cansu A1 - Benim, Ali Cemal A1 - Joos, Franz T1 - Analysis of the effect of nonuniform surface temperature distribution on the performance of a thermoelectric generator JF - Sustainable Energy Technologies and Assessments Y1 - 2022 U6 - https://doi.org/10.1016/j.seta.2022.102375 SN - 2213-1388 VL - 53 IS - A PB - Elsevier ER - TY - JOUR A1 - Benim, Ali Cemal A1 - Neuhoff, H. G. T1 - Analysis of erosion behaviour in a turbocharger radial turbine JF - International Journal for Numerical Methods in Fluids N2 - An analysis of the erosion behaviour of a turbocharger radial turbine is presented. The solution domain includes both sides of the radial turbine scroll with double intake and the rotor channel. In the analysis a dilute gas‐particle flow assumption is employed. The gas turbulence is defined by the k‐ε model. In solving the gas phase equation, the computer code Harwell‐FLOW3D is employed, which is based on a finite volume formulation using non‐orthogonal body‐fitted structured gridding and a pressure correction method. The particle phase is described by a Lagrangian approach, while particle paths are computed deterministically, neglecting the turbulent dispersion. For the computation of particle trajectories the code PTRACK is employed, which has been developed at ABB. Computations are carried out for several particle size classes. The results show that particles are thrown back into the scroll by the rotor at high rates. This seems to be the main source of erosion effects in the scroll. It has been observed that particles are unequally distributed between the scroll sides on their re‐entry, resulting in greater erosion on one of the scroll sides. The maximum erosion along the scroll is found to be likely to occur near the scroll end. KW - Erosion KW - Abgasturbolader KW - Radialturbine Y1 - 1993 U6 - https://doi.org/10.1002/fld.1650160402 SN - 0271-2091 VL - 16 IS - 4 SP - 259 EP - 285 PB - Wiley ER - TY - JOUR A1 - Pfeiffelmann, Björn A1 - Diederich, Michael A1 - Gül, Fethi A1 - Benim, Ali Cemal A1 - Hamberger, Andreas A1 - Heese, Markus T1 - Analysis of combustion, heat and fluid flow in a biomass furnace JF - E3S Web of Conferences KW - DOAJ Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-27880 SN - 2267-1242 VL - 128 PB - edp sciences ER - TY - JOUR A1 - Mandal, Dipak Kumar A1 - Biswas, Nirmalendu A1 - Manna, Nirmal K. A1 - Gayen, Dilip Kumar A1 - Benim, Ali Cemal T1 - An application of artificial neural network (ANN) for comparative performance assessment of solar chimney (SC) plant for green energy production JF - Scientific Reports N2 - This study aims to optimize the power generation of a conventional Manzanares solar chimney (SC) plant through strategic modifications to the collector inlet height, chimney diameter, and chimney divergence. Employing a finite volume-based solver for numerical analysis, we systematically scrutinize influential geometric parameters, including collector height (hi = 1.85 to 0.1 m), chimney inlet diameter (dch = 10.16 to 55.88 m), and chimney outlet diameter (do = 10.16 to 30.48 m). Our findings demonstrate that reducing the collector inlet height consistently leads to increased power output. The optimal collector inlet height of hi = 0.2 m results in a significant power increase from 51 to 117.42 kW (~ 2.3 times) without additional installation costs, accompanied by an efficiency of 0.25%. Conversely, enlarging the chimney diameter decreases the chimney base velocity and suction pressure. However, as turbine-driven power generation rises, the flow becomes stagnant beyond a chimney diameter of 45.72 m. At this point, power generation reaches 209 kW, nearly four times greater than the Manzanares plant, with an efficiency of 0.44%. Nevertheless, the cost of expanding the chimney diameter is substantial. Furthermore, the impact of chimney divergence is evident, with power generation, collector efficiency, overall efficiency, and collector inlet velocity all peaking at an outer chimney diameter of 15.24 m (corresponding to an area ratio of 2.25). At this configuration, power generation increases to 75.91 kW, approximately 1.5 times more than the initial design. Remarkably, at a low collector inlet height of 0.2 m, combining it with a chimney diameter of 4.5 times the chimney inlet diameter (4.5dch) results in an impressive power output of 635.02 kW, signifying a substantial 12.45-fold increase. To model the performance under these diverse conditions, an artificial neural network (ANN) is effectively utilized. KW - HSD Publikationsfonds KW - DFG Publikationskosten Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-45190 SN - 2045-2322 N1 - Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - 532148125 and supported by the central publication fund of Hochschule Düsseldorf University of Applied Sciences VL - 14 IS - 1 PB - Springer Nature ER - TY - JOUR A1 - Benim, Ali Cemal A1 - Diederich, Michael A1 - Pfeiffelmann, Björn T1 - Aerodynamic Optimization of Airfoil Profiles for Small Horizontal Axis Wind Turbines JF - Computation KW - DOAJ Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-25143 SN - 2079-3197 VL - 6 IS - 2 PB - MDPI ER - TY - JOUR A1 - Benim, Ali Cemal A1 - Canal, Cansu Deniz A1 - Boke, Yakup Erhan T1 - A Validation Study for RANS Based Modelling of Swirling Pulverized Fuel Flames JF - Energies N2 - A swirling pulverized coal flame is computationally investigated. A Eulerian–Lagrangian formulation is used to describe the two-phase flow. Turbulence is modelled within a RANS (Reynolds averaged numerical simulation) framework. Four turbulence viscosity- (TV) based models, namely the standard k-ε model, realizable k-ε model, renormalization group theory k-ε model, and the shear stress transport k-ω model are used. In addition, a Reynolds stress transport model (RSM) is employed. The models are assessed by comparing the predicted velocity fields with the measurements of other authors. In terms of overall average values, the agreement of the predictions to the measurements is observed to be within the range 20–40%. A better performance of the RSM compared to the TV models is observed, with a nearly twice as better overall agreement to the experiments, particularly for the swirl velocity. In the second part of the investigation, the resolution of the discrete particle phase in modelling the turbulent particle dispersion (TPD) and particle size distribution (SD) is investigated. Using the discrete random walk model for the TPD, it is shown that even five random walks are sufficient for an accuracy that is quite high, with a less than 1% mean deviation from the solution obtained by thirty random walks. The approximation of the measured SD is determined by a continuous Rosin–Rammler distribution function, and inaccuracies that can occur in its subsequent discretization are demonstrated and discussed. An investigation on the resolution of the SD by discrete particle size classes (SC) indicates that 12 SC are required for an accuracy with a less than 1% mean deviation from the solution with 18 SC. Although these numbers may not necessarily be claimed to be sufficiently universal, they may serve as guidance, at least for SD with similar characteristics KW - DOAJ Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-37365 SN - 1996-1073 VL - 14 IS - 21 PB - MDPI ER - TY - JOUR A1 - Mabrouk, Riheb A1 - Naji, Hassane A1 - Benim, Ali Cemal A1 - Dhahri, Hacen T1 - A State of the Art Review on Sensible and Latent Heat Thermal Energy Storage Processes in Porous Media: Mesoscopic Simulation JF - Applied Sciences KW - DOAJ Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-40343 VL - 12 IS - 14 PB - MDPI ER - TY - JOUR A1 - Benim, Ali Cemal A1 - Zinser, Walter T1 - A segregated formulation of Navier-Stokes equations with finite elements JF - Computer Methods in Applied Mechanics and Engineering KW - Navier-Stokes-Gleichung KW - Turbulente Strömung KW - Finite-Elemente-Methode KW - Numerische Strömungssimulation Y1 - 1986 U6 - https://doi.org/10.1016/0045-7825(86)90015-0 SN - 0045-7825 VL - 57 IS - 2 SP - 223 EP - 237 PB - Elsevier ER - TY - JOUR A1 - Benim, Ali Cemal A1 - Çiçek, Aydın A1 - Eker, Arif Mert T1 - A numerical analysis of the thermohydraulics of an EGS project in Turkey JF - MATEC Web of Conferences Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-27910 SN - 2261-236X VL - 240 PB - edp sciences ER - TY - JOUR A1 - Aslan, Erman A1 - Nahavandi, A. A1 - Taymaz, I. A1 - Benim, Ali Cemal T1 - A note on modelling non-rectangular boundaries by the Lattice Boltzmann Method JF - Progress in Computational Fluid Dynamics, An International Journal Y1 - 2012 U6 - https://doi.org/10.1504/pcfd.2012.049815 VL - 12 IS - 6 SP - 433 EP - 438 PB - inderscience ER -