Pressure drop and heat transfer characteristics of nanofluids in horizontal microtubes under thermally developing flow conditions

Name: Pressure drop and heat transfer characteristics of nanofluids in horizontal microtubes under thermally developing flow conditions
Author: Karimzadehkhouei, M., Yalçın, S. E., Şendur, K., Mengüç, Mustafa Pınar, Koşar, A.

İsim	Pressure drop and heat transfer characteristics of nanofluids in horizontal microtubes under thermally developing flow conditions
Yazar	Karimzadehkhouei, M., Yalçın, S. E., Şendur, K., Mengüç, Mustafa Pınar, Koşar, A.
Basım Tarihi:	2015-10
Basım Yeri	- Elsevier
Konu	Nanoparticle, Nanofluid, Single-phase flow, Friction factor, Heat transfer coefficient
Tür	Süreli Yayın
Dil	İngilizce
Dijital	Evet
Yazma	Hayır
Kütüphane:	Özyeğin Üniversitesi
Demirbaş Numarası	0894-1777
Kayıt Numarası	8d18b632-66ed-4d17-9728-818730a2c602
Lokasyon	Mechanical Engineering
Tarih	2015-10
Notlar	Due to copyright restrictions, the access to the full text of this article is only available via subscription.
Örnek Metin	This study presents pressure drop and heat transfer characteristics of water based nanofluids with TiO2 and Al2O3 nanoparticles of various mass fractions in horizontal smooth hypodermic microtubes with an outer diameter of ∼717 μm and an inner diameter of ∼502 μm over a wide variety of Reynolds numbers under hydrodynamically fully developed and thermally developing conditions. For this purpose, TiO2 and Al2O3 nanoparticles of 20 nm average solid diameters were added to deionized water to prepare nanofluids with mass fractions of 0.01–3 wt.%, and prepared nanofluids were characterized by standard methods such as Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM), and zeta potential measurements. Experimental friction factor coefficients were predicted within ±10% and are in good agreement with existing analytical predictions, while experimental heat transfer coefficients were predicted within ±15% with existing correlations for single phase flow. Our results show that there is no considerable heat transfer enhancement for Re < 1000. A consistent enhancement in heat transfer was observed (for average heat transfer coefficient up to 25%), once Reynolds number goes beyond 1500. At low Reynolds numbers, flow is mainly laminar. However, at higher Reynolds numbers, flow starts to transition to turbulent flow, when heat transfer enhancement is also observed. Under these conditions, the enhancement in heat transfer increases with mass fraction.
DOI	10.1016/j.expthermflusci.2014.10.013
Cilt	67

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Pressure drop and heat transfer characteristics of nanofluids in horizontal microtubes under thermally developing flow conditions

Yazar Karimzadehkhouei, M., Yalçın, S. E., Şendur, K., Mengüç, Mustafa Pınar, Koşar, A.

Basım Tarihi 2015-10

Basım Yeri - Elsevier

Konu Nanoparticle, Nanofluid, Single-phase flow, Friction factor, Heat transfer coefficient

Tür Süreli Yayın

Dil İngilizce

Dijital Evet

Yazma Hayır

Kütüphane Özyeğin Üniversitesi

Demirbaş Numarası 0894-1777

Kayıt Numarası 8d18b632-66ed-4d17-9728-818730a2c602

Lokasyon Mechanical Engineering

Tarih 2015-10

Notlar Due to copyright restrictions, the access to the full text of this article is only available via subscription.

Örnek Metin This study presents pressure drop and heat transfer characteristics of water based nanofluids with TiO2 and Al2O3 nanoparticles of various mass fractions in horizontal smooth hypodermic microtubes with an outer diameter of ∼717 μm and an inner diameter of ∼502 μm over a wide variety of Reynolds numbers under hydrodynamically fully developed and thermally developing conditions. For this purpose, TiO2 and Al2O3 nanoparticles of 20 nm average solid diameters were added to deionized water to prepare nanofluids with mass fractions of 0.01–3 wt.%, and prepared nanofluids were characterized by standard methods such as Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM), and zeta potential measurements. Experimental friction factor coefficients were predicted within ±10% and are in good agreement with existing analytical predictions, while experimental heat transfer coefficients were predicted within ±15% with existing correlations for single phase flow. Our results show that there is no considerable heat transfer enhancement for Re < 1000. A consistent enhancement in heat transfer was observed (for average heat transfer coefficient up to 25%), once Reynolds number goes beyond 1500. At low Reynolds numbers, flow is mainly laminar. However, at higher Reynolds numbers, flow starts to transition to turbulent flow, when heat transfer enhancement is also observed. Under these conditions, the enhancement in heat transfer increases with mass fraction.

DOI 10.1016/j.expthermflusci.2014.10.013

Cilt 67