### Abstract

Two-dimensional steady natural convection heat transfer to water based nanofluids (TiO_{2}-water, Al_{2}Ol_{2}-water, and Cu-water) flowing over a stretching cylinder has been investigated numerically. Using the similarity transformations, the continuity, momentum, and energy equations are reduced to a set of nonlinear, ordinary differential equations. These equations are solved numerically using MATLAB. Because of the algebraic decay of the similarity functions, numerical integration is performed using a compressed coordinate. The axial velocity is the result of forced convection due to stretching, and natural convection induced by the heated cylinder. The results show that the flow velocity with a nanofluid is smaller compared with the velocity of the base fluid for the same stretching and heating conditions, which is basically caused by the increase of viscosity and density. The presence of nanoparticles reduces the thickness of the hydrodynamic boundary layer and enhances the heat transfer rate. The location of the zero shear stress on the surface of the cylinder occurs at shorter and shorter distances (along the cylinder) as the solid volume fraction of nanoparticles increases.

Original language | English |
---|---|

Pages (from-to) | 31-42 |

Number of pages | 12 |

Journal | International Journal of Heat and Technology |

Volume | 30 |

Issue number | 2 |

Publication status | Published - 2012 |

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### Keywords

- Convection
- Heat transfer
- Nanofluid
- Similarity solution
- Stretching cylinder

### ASJC Scopus subject areas

- Condensed Matter Physics
- Fluid Flow and Transfer Processes

### Cite this

**Heat transfer in water based nanofluids (TiO2-H2O, Al2O3-H2O and Cu-H2O) over a stretching cylinder.** / Rahman, M. M.; Ariz, A.

Research output: Contribution to journal › Article

*International Journal of Heat and Technology*, vol. 30, no. 2, pp. 31-42.

}

TY - JOUR

T1 - Heat transfer in water based nanofluids (TiO2-H2O, Al2O3-H2O and Cu-H2O) over a stretching cylinder

AU - Rahman, M. M.

AU - Ariz, A.

PY - 2012

Y1 - 2012

N2 - Two-dimensional steady natural convection heat transfer to water based nanofluids (TiO2-water, Al2Ol2-water, and Cu-water) flowing over a stretching cylinder has been investigated numerically. Using the similarity transformations, the continuity, momentum, and energy equations are reduced to a set of nonlinear, ordinary differential equations. These equations are solved numerically using MATLAB. Because of the algebraic decay of the similarity functions, numerical integration is performed using a compressed coordinate. The axial velocity is the result of forced convection due to stretching, and natural convection induced by the heated cylinder. The results show that the flow velocity with a nanofluid is smaller compared with the velocity of the base fluid for the same stretching and heating conditions, which is basically caused by the increase of viscosity and density. The presence of nanoparticles reduces the thickness of the hydrodynamic boundary layer and enhances the heat transfer rate. The location of the zero shear stress on the surface of the cylinder occurs at shorter and shorter distances (along the cylinder) as the solid volume fraction of nanoparticles increases.

AB - Two-dimensional steady natural convection heat transfer to water based nanofluids (TiO2-water, Al2Ol2-water, and Cu-water) flowing over a stretching cylinder has been investigated numerically. Using the similarity transformations, the continuity, momentum, and energy equations are reduced to a set of nonlinear, ordinary differential equations. These equations are solved numerically using MATLAB. Because of the algebraic decay of the similarity functions, numerical integration is performed using a compressed coordinate. The axial velocity is the result of forced convection due to stretching, and natural convection induced by the heated cylinder. The results show that the flow velocity with a nanofluid is smaller compared with the velocity of the base fluid for the same stretching and heating conditions, which is basically caused by the increase of viscosity and density. The presence of nanoparticles reduces the thickness of the hydrodynamic boundary layer and enhances the heat transfer rate. The location of the zero shear stress on the surface of the cylinder occurs at shorter and shorter distances (along the cylinder) as the solid volume fraction of nanoparticles increases.

KW - Convection

KW - Heat transfer

KW - Nanofluid

KW - Similarity solution

KW - Stretching cylinder

UR - http://www.scopus.com/inward/record.url?scp=84874769562&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84874769562&partnerID=8YFLogxK

M3 - Article

VL - 30

SP - 31

EP - 42

JO - International Journal of Heat and Technology

JF - International Journal of Heat and Technology

SN - 0392-8764

IS - 2

ER -