**Numerical Simulation of Nanoparticles with Variable Viscosity over a Stretching Sheet** Numerical Simulation of Nanoparticles with Variable Viscosity over a Stretching Sheet

DOI: 10.5772/intechopen.71224

Noreen Sher Akbar, Dharmendra Tripathi and Zafar Hayat Khan Noreen Sher Akbar, Dharmendra Tripathi and

Additional information is available at the end of the chapter Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.71224

### Abstract

Zafar Hayat Khan

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272 Numerical Simulations in Engineering and Science

The effects of different types of base fluids on carbon nanotube (CNT) nanofluids flow over a circular stretching sheet are numerically analyzed. The nonlinear variation of radial velocity in radial direction is assumed at surface of stretching sheet. The temperature dependent fluid viscosity is taken into consideration. Two different types of flows (assisting flow and opposing flow) are discussed under the buoyant force effects. Single walled CNT and multi walled CNT are considered as nanoparticles for better thermal conductivity of the nanofluids. A set of similarity transformations to convert the partial differential equations into ordinary differential equations is hired. The non-linear ODEs are numerically solved by employing fourth order Runge-Kutta method. Discussions of numerical simulations for flow characteristics have been made appropriately. A comparative study for various type of base fluids like kerosene, engine oil and ethylene glycol is also presented. From the predicted simulation, it is observed that the variation in Nusselt number is maximum for engine oil and minimum for kerosene oil however, the variation in skin friction coefficient is largest for kerosene oil and least for engine oil. Furthermore, numerical results are also validated with achieving a good correlation with existing results.

Keywords: CNT nanofluids, nonlinear stretching sheet, Runge-Kutta method, buoyancy force, heat transfer, similarity transformation
