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Advancing nanofluid numerical modelling: A novel Euler–Lagrange method with experimental validation
Nejc Vovk, Blaž Kamenik, Elif Begum Elcioglu, Erdem Ozyurt, Ziya Haktan Karadeniz, Alpaslan Turgut, Jure Ravnik, 2025, original scientific article

Abstract: We present a novel approach to numerical modelling of thermal nanofluids based on the Euler–Lagrange method. This approach overcomes the challenge of extremely fine temporal discretization, which previous Euler–Lagrange nanofluid numerical models struggled to address, while also avoiding the need for too many Lagrangian nanoparticles. A numerical uncertainty assessment method is adapted for the proposed approach. The model is validated with a simple verification case and applied to simulate a closed natural circulation loop heat exchanger operating with heating power ranging from 10 W to 50 W and nanoparticle volume fractions of 0.5% to 2%, using an Al2O3–water nanofluid. Results are compared with experimental temperature measurements and an Euler–Euler implementation of the same nanofluid. The model is also applied to simulate the natural convection inside a vertical enclosure, studied experimentally by other authors. The proposed novel approach demonstrates agreement with both experimental data and the Euler–Euler implementation, effectively capturing the overall behaviour of nanofluids. We establish, that the interplay of multiple transport phenomena, that occur in nanofluid operated devices, can be difficult to completely reproduce numerically within the framework of current modelling assumptions.
Keywords: Euler–Lagrange nanofluid modelling, numerical uncertainty assessment, natural convection loop simulation, nanoparticle concentration analysis, nanofluid heat transfer
Published in DKUM: 17.06.2025; Views: 0; Downloads: 7
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Euler–Euler numerical model for transport phenomena modeling in a natural circulation loop operated by nanofluids
Blaž Kamenik, Nejc Vovk, Elif Begum Elcioglu, Firat Sezgin, Erdem Ozyurt, Ziya Haktan Karadeniz, Alpaslan Turgut, Jure Ravnik, 2025, original scientific article

Abstract: This paper explores a computational approach to model multiphase heat transfer and fuid fow in a natural circulation loop utilizing nanofuids. We propose and implement an Euler–Euler framework in a CFD environment, incorporating an innovative boundary condition to preserve mass conservation during thermophoretic particle fux. The model’s accuracy is verifed through a one-dimensional example, by comparing results against both an Euler–Lagrange model and an in-house fnite volume solution. Experimental validation is conducted with aluminum oxide nanofuids at varying nanoparticle concentrations. We prepared the nanofuids and measured their thermophysical properties up to 60◦C. We assess the thermal performance of the nanofuid in natural circulation loop at diferent heating powers via experiment and numerical simulations. The fndings reveal that the heat transfer enhancement ofered by the nanofuid is modest, with minimal diferences observed between the proposed Euler–Euler approach and a simpler single-phase model. The results underscore that while the Euler–Euler model ofers detailed particle–fuid interactions, its practical thermal advantage is limited in this context.
Keywords: CFD · Euler–Euler, multiphase fow, nanofluid, natural circulation loop, thermophoresis
Published in DKUM: 12.03.2025; Views: 0; Downloads: 6
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