Pemodelan Dinamika Fouling Nanofluida Ni dan NiO Pada Sistem Penukar Panas

Sihombing, Erick Rafael (2025) Pemodelan Dinamika Fouling Nanofluida Ni dan NiO Pada Sistem Penukar Panas. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Nanofluida merupakan inovasi fluida kerja yang dikembangkan untuk meningkatkan performa perpindahan panas pada sistem termal, termasuk penukar panas. Namun, performa penukar panas akan menurun karena penggunaan nanofluida sehingga material di permukaan perpindahan panas akan terakumulasi (fouling). Fouling mengurangi efisiensi termal sehingga menghasilkan pressure drop tinggi. Penelitian ini bertujuan untuk menginvestigasi dinamika pembentukan fouling menggunakan nanofluida Ni dan NiO dan mengembangkan model matematis untuk memprediksi perilakunya. Metode penelitian meliputi sintesis dan karakterisasi nanopartikel, preparasi dan karakterisasi sifat termofisika dan kestabilan dispersi nanofluida, simulasi CFD, eksperimen pembentukan fouling dengan berbagai variasi (konsentrasi, kecepatan, dan temperatur), serta pemodelan dan validasi model. Nanopartikel Ni dan Nio berhasil disintesis dengan ukuran kristal 1,4 dan 25,6 nm. Analisis SEM memberikan struktur berpori nanopartikel Ni sedangkan nanopartikel NiO berstruktur kristalin dan teraglomerasi. Peningkatan konsentrasi menaikkan konduktivitas termal tetapi terdapat titik jenuh sehingga kapasitasnya meningkat. Stabilitas dispersi nanofluida Ni lebih unggul daripada NiO. Pemodelan fouling diusulkan berdasarkan formulasi Sigmoidal-Boltzmann. Hasil fitting menunjukkan model mampu merepresentasikan data eksperimen dengan sangat baik, dibuktikan dengan nilai koefisien determinasi (R2) yang konsisten tinggi. Sebagaian besar hasil fitting menunjukkan nanofluida Ni memiliki nilai
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Nanofluids are an innovative working fluid developed to improve heat transfer performance in thermal systems, including heat exchangers. However, the performance of heat exchangers will decrease due to the use of nanofluids, causing material to accumulate on the heat transfer surface (fouling). Fouling reduces thermal efficiency, resulting in high pressure drops. This study aims to investigate the dynamics of fouling formation using Ni and NiO nanofluids and to develop a mathematical model to predict its behaviour. The research methods include the synthesis and characterisation of nanoparticles, the preparation and characterisation of the thermophysical properties and dispersion stability of nanofluids, CFD simulations, fouling formation experiments with various variations (concentration, velocity, and temperature), as well as modelling and model validation. Ni and NiO nanoparticles were successfully synthesised with crystal sizes of 1.4 and 25.6 nm. SEM analysis revealed a porous structure in Ni nanoparticles, while NiO nanoparticles exhibited a crystalline structure and agglomeration. Increasing concentration enhances thermal conductivity, but there is a
saturation point in NiO nanofluids, whereas in Ni nanofluids, it tends to decrease. Meanwhile, the heat capacity decreases with increasing mass fraction. The dispersion stability of Ni nanofluids is superior to that of NiO. Fouling modelling was proposed based on the SigmoidalBoltzmann formulation. The fitting results show that the model can represent the experimental data very well, as evidenced by the consistently high coefficient of determination (R²) values that can accommodate fouling curves (asymptotic exponential and linear). Most of the fitting results show that Ni nanofluids have higher

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Nanofluida, Penukar Panas, Fouling, Sigmoidal-Boltzmann Nanofluid, Heat Exchanger, Fouling, Sigmoidal-Boltzmann
Subjects:	T Technology > TA Engineering (General). Civil engineering (General) > TA357 Computational fluid dynamics. Fluid Mechanics
Divisions:	Faculty of Industrial Technology and Systems Engineering (INDSYS) > Physics Engineering > 30201-(S1) Undergraduate Thesis
Depositing User:	Erick Rafael Sihombing
Date Deposited:	28 Jul 2025 06:35
Last Modified:	28 Jul 2025 06:35
URI:	http://repository.its.ac.id/id/eprint/122064

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