Sistem Pengukuran Konduktivitas Dan Kapasitas Panas Berbasis Metode Transient Hot Wire (THW) Dengan Kawat Tembaga

Siburian, Christian Delon (2026) Sistem Pengukuran Konduktivitas Dan Kapasitas Panas Berbasis Metode Transient Hot Wire (THW) Dengan Kawat Tembaga. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Nanofluida merupakan fluida yang berpotensi digunakan untuk meningkatkan kinerja perpindahan panas sehingga diperlukan metode pengukuran sifat termal yang dapat mengevaluasi konduktivitas dan kapasitas panas. Salah satu metode yang dapat digunakan adalah Transient Hot Wire (THW), pengukuran konduktivitas panas melalui respons temperatur kawat terhadap waktu. Penelitian ini bertujuan melakukan sintesis dan karakterisasi Carbon Quantum Dots (CQDs) menggunakan prekursor ampas bubuk teh dan asam sitrat-urea, kemudian digunakan sebagai fluida uji, serta mengevaluasi pengaruh geometri kawat tembaga terhadap pengukuran berbasis Transient Hot Wire (THW). Sistem THW menggunakan kawat tembaga sepanjang 10 cm dengan diameter 135, 150, dan 280 µm dengan pengujian awal yaitu Temperature Coefficient of Resistance (TCR) dimana, diameter kawat yang lebih kecil menghasilkan resistansi dan respons perubahan temperatur yang lebih besar. Kawat berdiameter 135 µm memberikan hasil terbaik dengan kenaikan temperatur maksimum 0,71 °C pada arus 1 A, error sebesar 10,67% terhadap alat standar BAXIT TPHS dan ketidakpastian diperluas sebesar 5,88% pada fluida akuades. Pengukuran CQDs menunjukkan konduktivitas termal berubah terhadap konsentrasi, tetapi tidak menunjukkan peningkatan yang konsisten. Sementara itu, kapasitas panas tidak dapat ditentukan secara andal karena penentuan difusivitas panas dari intersep kurva ΔT terhadap ln(t) sangat sensitif terhadap kondisi awal pengukuran dan penyimpangan sistem dari model THW ideal. Dengan demikian, kawat tembaga diameter 135 µm merupakan geometri terbaik dari pengujian konduktivitas termal yang dilakukan.
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Nanofluids have the potential to enhance heat-transfer performance; therefore, a thermal-property measurement method capable of evaluating thermal conductivity and specific heat capacity is required. One applicable method is the Transient Hot Wire (THW) technique, which determines thermal conductivity based on the temperature response of a wire over time. This study aimed to synthesize and characterize Carbon Quantum Dots (CQDs) using tea-powder waste and citric acid-urea as precursors, employ the resulting CQDs as test fluids, and evaluate the effect of copper-wire geometry on THW-based measurements. The THW system used 10 cm long copper wires with diameters of 135, 150, and 280 µm. Initial characterization was conducted by determining the Temperature Coefficient of Resistance (TCR), showing that smaller wire diameters produced higher electrical resistance and a greater temperature-change response. The 135 µm diameter wire provided the best measurement performance, with a maximum temperature rise of 0.71 °C at a current of 1 A, a relative error of 10.67% compared with the standard BAXIT TPHS instrument, and an expanded uncertainty of 5.88%. Measurements of the CQD nanofluids showed that thermal conductivity varied with concentration but did not exhibit a consistent increasing trend. Meanwhile, specific heat capacity could not be determined reliably because the thermal diffusivity obtained from the intercept of the ΔT versus ln(t) curve was highly sensitive to the initial measurement conditions and deviations of the system from the ideal THW model. Therefore, among the tested variations, the 135 µm diameter copper wire was identified as the most suitable geometry for thermal-conductivity measurements.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	carbon quantum dots (CQDs), kawat tembaga, konduktivitas, transient hot wire (THW), copper wire, thermal conductivity
Subjects:	Q Science > QC Physics > QC100.5 Measuring instruments (General) Q Science > QC Physics > QC271 Temperature measurements Q Science > QC Physics > QC320 Heat transfer T Technology > TA Engineering (General). Civil engineering (General) > TA593.35 Instruments, cameras, etc.
Divisions:	Faculty of Industrial Technology and Systems Engineering (INDSYS) > Physics Engineering > 30201-(S1) Undergraduate Thesis
Depositing User:	Christian Delon Siburian
Date Deposited:	04 Aug 2026 03:23
Last Modified:	04 Aug 2026 03:23
URI:	http://repository.its.ac.id/id/eprint/142260

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