AC hot wire measurement of thermophysical properties of nanofluids with 3ω method

Turgut, Alpaslan; Sauter, Christian; Chirtoc, M.; Henry, J.F.; Tavman, Şebnem; Tavman, İsmail; Pelzl, J.

doi:10.1140/epjst/e2008-00459-7

Cited by 29 publications

(18 citation statements)

References 5 publications

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“…We determined previously k and a enhancements of about 3% and 4.5% respectively for 12% wt Aerosil 200V silica nanoparticles (12 nm in diameter) in water, using Eqs. (2a,b) [1]. In Ref.…”

Section: Resultsmentioning

confidence: 99%

“…(1c) allow for simultaneous and independent determination sample's k and a relative to a reference medium (index r) having similar properties [1]:…”

Section: Theoretical Backgroundmentioning

confidence: 99%

“…Recently we reported on simultaneous thermal conductivity k and thermal diffusivity a measurement of liquids and in particular of nanofluids in a configuration using an ac excited hot wire combined with lock-in detection of the third harmonic (3ω method) [1]. The conductive wire is used as both heater and sensor.…”

mentioning

confidence: 99%

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Assessment of modulated hot wire method for thermophysical characterization of fluid and solid matrices charged with (nano)particle inclusions

Chirtoc¹,

Henry²,

Turgut

et al. 2010

J. Phys.: Conf. Ser.

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Assessment of modulated hot wire method for thermophysical characterization of fluid and solid matrices charged with (nano)particle inclusions Abstract. Recently we reported on simultaneous thermal conductivity k and thermal diffusivity a measurement of liquids and in particular of nanofluids in a configuration using an ac excited hot wire combined with lock-in detection of the third harmonic (3ω method) [1]. The conductive wire is used as both heater and sensor. The requirements for the asymptotic validity of the line heat source model are fulfilled at low modulation frequencies below a few Hz. The study of the relative sensitivity of signal amplitude and phase to changes in k and a indicates that there is an optimum frequency range for accurate and stable results. We extend by up to two decades the feasible frequency range for 3ω measurements by considering various more elaborate models for the heat transfer between the wire and the fluid. Finally we show that the same ac hot wire method can be applied to soft solid, composite materials. We measured the k enhancement of a poly(ethylene vinyl acetate) EVA polymer matrix charged with various fractions of graphite.

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“…We determined previously k and a enhancements of about 3% and 4.5% respectively for 12% wt Aerosil 200V silica nanoparticles (12 nm in diameter) in water, using Eqs. (2a,b) [1]. In Ref.…”

Section: Resultsmentioning

confidence: 99%

“…(1c) allow for simultaneous and independent determination sample's k and a relative to a reference medium (index r) having similar properties [1]:…”

Section: Theoretical Backgroundmentioning

confidence: 99%

See 1 more Smart Citation

Assessment of modulated hot wire method for thermophysical characterization of fluid and solid matrices charged with (nano)particle inclusions

Chirtoc¹,

Henry²,

Turgut

et al. 2010

J. Phys.: Conf. Ser.

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“…2.a), the results show there is almost no difference between the new oil and the aged ones. The variations are within a relative error of 2 %, which is inside the measurement instrument error (the thermal conductivity has been determined from a hot wire method coupled with a 3-omega response measurement [7]). The specific heat seems to decrease with temperature for the aged-alone oil (Fig.…”

Section: -3mentioning

confidence: 90%

Compatibility tests between Jarytherm® DBT synthetic oil and solid materials from wastes

Fasquelle

Falcoz

Neveu

et al. 2016

AIP Conference Proceedings

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Abstract. Direct thermocline thermal energy storage is the cheapest sensible thermal energy storage configuration. Indeed, a thermocline tank consists in one tank instead of two and reduces costs. Thermocline thermal energy storages are often filled with cheap solid materials which could react with the heat transfer fluid in the case of incompatibility. PROMES laboratory is building a pilot-scale parabolic trough solar loop including a direct thermocline thermal energy storage system. The working fluid will be a synthetic oil, the Jarytherm ® DBT, and the thermal energy storage tank will be filled with stabilized solid materials elaborated from vitrified wastes. Compatibility tests have been conducted in order to check on one hand if the thermo-mechanical properties and life time of the energy storage medium are not affected by the contact with oil and, on the other hand, if the thermal oil performances are not degraded by the solid filler. These experiments consisted in putting in contact the oil and the solid materials in small tanks. In order to discriminate the solid materials tested in the shortest time, accelerating aging conditions at 330 °C for 500 hours were used. The measurements consisted in X-Ray Diffraction and Scanning Electron Microscopy for the solids, and thermo-physical and chemical properties measurements for the oil. Regarding the solid samples, their crystalline structure did not change during the test, but it is difficult to conclude about their elementary composition and they seem to absorb oil. While thermal properties still makes Jarytherm ® DBT a good heat transfer fluid after the accelerated aging tests, this study results in differentiating most compatible materials. Thus according to our study, Jarytherm ® DBT can be used in direct thermocline thermal energy storage applications when compatibility of the solid material has been demonstrated.

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“…3 geriliminin genlik ve frekans bağlılığı sayesinde, numunenin ısıl özellikleri elde edilebilir. Yöntem ile ilgili geniş bilgi daha önceki çalışmalarda [45,[48][49][50]] detaylı olarak verildiği için burada kısaca bahsedilmiştir. Sistemin şematik görünüşü Şekil 1'de verilmiştir.…”

Section: ω Yöntemi (3ω Method)unclassified

Nanoakişkanlarin Isil İletkenli̇k Ve Vi̇skozi̇tesi̇ni̇n Deneysel İncelenmesi̇: Taneci̇k Boyutu Etki̇si̇

Turgut

Sağlanmak

Doğanay

2016

Gazi Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi

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ÖZETYeni nesil ısı transfer akışkanı olma potansiyeli taşıyan nanoakışkanlar ile ilgili araştırmalar on yılı aşkın bir süre önce başlamasına rağmen, yayınlanan çalışmaların sonuçları arasında birçok tutarsızlık ve çelişkiler mevcuttur. Bunlardan birisi tanecik boyutunun nanoakışkanın ısıl performansına olan etkisidir. Bu çalışmada, 10 nm ve 30 nm tanecik boyutuna sahip Al 2 O 3 -su nanoakışkanların, hacimce % 1, 2, 3 ve 6,33 katkı oranlarında, ısıl iletkenlik ve viskozite değerleri deneysel olarak belirlenmiş ve elde edilen sonuçlar literatürde yer alan efektif ısıl iletkenlik ve efektif viskozite modelleri ile karşılaştırılmıştır. Isıl iletkenliğin, tanecik boyutu ile ilişkili olmadığı ve deneysel sonuçlarımızın klasik efektif ısıl iletkenlik modellerinden biri olan Maxwell ile uyumlu olduğu gözlenmiştir. Reolojik ölçümler sonucunda, numunelerin Newton tipi akışkan davranışı gösterdikleri ve aynı tanecik katkı oranında, daha büyük tanecik boyutuna sahip numunelerin viskozitelerindeki artış oranının daha yüksek olduğu sonucuna varılmıştır. Klasik efektif viskozite modellerinden Einstein modeli, deneysel sonuçlarımız ile karşılaştırıldığında çok düşük değerlere sahiptir.Anahtar Kelimeler: Nanoakışkan, ısıl iletkenlik, viskozite, tanecik boyutu etkisi EXPERIMENTAL INVESTIGATION ON THERMAL CONDUCTIVITY AND VISCOSITY OF NANOFLUIDS: PARTICLE SIZE EFFECT ABSTRACTAlthough, it has been more than a decade since research started on nanofluids, potential heat transfer fluids of next generation, there are still inconsistent and contradictory results between studies. Among these results, one is the effect of particle size on thermal performance of a nanofluid. In this study, thermal conductivity and viscosity of Al 2 O 3 -deionized water nanofluids with different particle size (10 and 30 nm) and concentration (1 to 6.33 % vol.) were studied experimentally, and the results were compared with the effective thermal conductivity and effective viscosity models from the literature. It is observed that, particle size has no effect on the thermal conductivity of nanofluid and our experimental results are in a good agreement with Maxwell model, one of the classical effective thermal conductivity models. The results of the rheological measurements indicate that, nanofluid samples show a Newtonian fluid behavior and for the given particle volume concentration, bigger particle size gives a higher increase on the viscosity of the sample. Einstein model, one of the classical effective viscosity model, fails to predict the viscosity of nanofluid samples.

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AC hot wire measurement of thermophysical properties of nanofluids with 3ω method

Cited by 29 publications

References 5 publications

Assessment of modulated hot wire method for thermophysical characterization of fluid and solid matrices charged with (nano)particle inclusions

Assessment of modulated hot wire method for thermophysical characterization of fluid and solid matrices charged with (nano)particle inclusions

Compatibility tests between Jarytherm® DBT synthetic oil and solid materials from wastes

Nanoakişkanlarin Isil İletkenli̇k Ve Vi̇skozi̇tesi̇ni̇n Deneysel İncelenmesi̇: Taneci̇k Boyutu Etki̇si̇

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