Abstract
A numerical study including a validation process with experimental data was performed on the forced convection flows of nanofluids; the object of study was water containing TiO2 nanoparticles in smooth and micro-fin tubes at a constant wall temperature. Constant heat flux and temperature-dependent properties were used to determine the hydrodynamics and thermal behaviors of the nanofluid flow;a single-phase numerical model was used to solve two-dimensional equations by means of a CFD program for the water flow, contained in a smooth tube and in various micro-fin tubes having various helix angles (0o, 18o). An extensive literature review on the determination of the physical properties (k, μ, ρ, Cp) of nanofluids is given in this paper. Multilayer Perceptron (MLP), one of theartificial neural network (ANN) methods, was used to determine the most agreeable physical propertiesof TiO2 nanofluids among correlations. The inputs ofthe ANN analyses were the correlations of physical properties, the average temperature and velocity of water in the test tubes, and the nanoparticle concentrations, while the outputs were shear stress, friction factor, heat flux, convective heat transfer coefficient, and pressure drop. After obtaining the best combination of physical properties of TiO2 nanofluids from the ANN analyses, the numerical model was validated by means of a CFD program,with the experimental smooth tube data as a case study; it was also validatedas a simulation studyfor several micro-fin tubes through a CFD program. This paper shows temperature, pressure, and velocity distributions in the investigated tubes; in addition, average and local experimental, theoretical, and numerical values in the smooth and micro-fin tubes are compared with oneanother in terms of friction factors, shear stresses, convective heat transfer coefficients, and pressure drops, according to various nanoparticle concentrations.
Keywords: Heat transfer coefficient, Pressure drop, ANN, Nanofluid, Single-phase flow, CFD
Call for Papers in Thematic Issues
Role of nanomaterials in fabrication of coatings, Machining and Joining
The application of nanoscience has brought about a revolution in the field of mechanical engineering by providing novel materials, boosting manufacturing processes, and generating cutting-edge products. The purpose of this special issue is to investigate the enormous impact that nanoscience has had on mechanical engineering, with a particular emphasis on ...read more
Advanced Inorganic Nanocomposites and Their Emerging Applications
This special issue collection will highlight developments on the recent trends about the synthesis of metal oxides, nanoclusters, biomaterials, 2D nanomaterials, nanocrystals, nanocomposites, etc. and their applications in electrochemical systems, tissue regeneration, energy storage and harvesting, sensors, etc. The novelty of the methods in the chemical synthesis and their characterizations, ...read more
Applicability of Nanotechnology for Performance Enhancement of Clean Energy Technologies
Population growth, industrialization, and improvement in living quality would lead to further increase in energy demand in near future. Regarding the disadvantages of fossil fuels such as fluctuations in their price, high emissions of greenhouse gases and restriction of their sources, it is crucial to use and exploit alternative energy ...read more
Graphene and 2D Materials for Energy Storage and Conversion
This thematic issue will discuss the recent advances in graphene-based nanomaterials for different energy technologies. Graphene possesses a high surface area, and stable structure and exhibits many interesting electronic, optical, and mechanical properties due to its 2D crystal structure. Graphene is of both fundamental interest and suitable for a wide ...read more
Related Books
Nanoscale Field Effect Transistors: Emerging Applications
Nanoelectronics Devices: Design, Materials, and Applications Part II
Nanoelectronics Devices: Design, Materials, and Applications (Part I)
Role of Nanotechnology in Cancer Therapy
Synthesis and Applications of Semiconductor Nanostructures
Pathways to Green Nanomaterials: Plants as Raw Materials, Reducing Agents and Hosts
Applications of Nanomaterials in Medical Procedures and Treatments
Synthesis of Nanomaterials
Nanobiotechnology: Principles and Applications
Bio-Inspired Nanotechnology
13