Experimental studies of flow boiling heat transfer by using nanofluids

Journal of Thermal Analysis and Calorimetry - Flow boiling heat transfer widely utilized in numerous industrial applications such as boiler tubes, evaporators and cooling of reactors in a nuclear...     

Experimental investigation of heat transfer enhancement in pool boiling using novel Ag/ZnO hybrid nanofluids

Journal of Thermal Analysis and Calorimetry - The present study aims at investigating the enhancements in thermal properties, CHF and HTC of novel Ag/ZnO hybrid nanofluid at various concentrations....     

Study on backward-facing step flow and heat transfer characteristics of hybrid nanofluids

Journal of Thermal Analysis and Calorimetry - As high heat dissipation has increasingly become the primary factor restricting the capability of electronic elements, and the high temperature of the...     

Fundamental and subphenomena of boiling heat transfer

Journal of Thermal Analysis and Calorimetry - Boiling process can be widely used in different industrial applications. In this two-phase heat transfer, the latent heat of vaporization of a liquid...     

Plated thermocouples for boiling heat transfer studies

Plated thermocouples are developed for the measurement of the temperatures of the inner and outer surfaces of the tube wall during the boiling heat transfer processes. A thin layer of a suitable metal is electroplated on the surface of the tube wall. The entire contacting surface between the plated layer and the base metal serves as the joint of the thermocouple. A wire of the same material as the tube is securely attached to the tube wall by embedding under an electrodeposited layer of the same metal. Another wire of the same material as the plated layer is securely attached to the plated layer by the same technique. There wires serve as the leads of the thermocouple represents the average temperature of the plated portion of the tube surface fairly accurately. The linearity and reproducibility of the temperature-emf relationship are also very good.     

An updated review of nanofluids in various heat transfer devices

Journal of Thermal Analysis and Calorimetry - The field of nanofluids has received interesting attention since the concept of dispersing nanoscaled particles into a fluid was first introduced in...     

Flow and heat transfer in non-Newtonian nanofluids over porous surfaces

In the present study, heat transfer and fluid flow of a pseudo-plastic non-Newtonian nanofluid over permeable surface has been solved in the presence of injection and suction. Similarity solution method is utilized to convert the governing partial differential equations into ordinary differential equations, which then is solved numerically using Runge–Kutta–Fehlberg fourth–fifth order (RKF45) method. The Cu, CuO, TiO₂ and Al₂O₃ nanoparticles are considered in this study along with sodium carboxymethyl cellulose (CMC)/water as base fluid. Validation has been done with former numerical results. The influence of power-law index, volume fraction of nanoparticles, nanoparticles type and permeability parameter on nanofluid flow and heat transfer was investigated. The results of the study illustrated that the flow and heat transfer of non-Newtonian nanofluid in the presence of suction and injection has different behaviors. For injection and the impermeable plate, the non-Newtonian nanofluid shows a better heat transfer performance compared to Newtonian nanofluid. However, changing the type of nanoparticles has a more intense influence on heat transfer process during suction. It was also observed that in injection, contrary to the other two cases, the usage of non-Newtonian nanofluid can decrease heat transfer in all cases.

     

Preparation and dispersion stability of aqueous metal oxide nanofluids for potential heat transfer applications: a review of experimental studies

Journal of Thermal Analysis and Calorimetry - Nanofluids have recently attracted attention of many researchers due to their growing potential applications in heat transfer devices. They possess...     

Potentials of boiling heat transfer in advanced thermal energy systems

Journal of Thermal Analysis and Calorimetry - Boiling process is a highly efficient mechanism of heat transfer, which has an important role in industrial and domestic sectors. In this process, a...     

Research and development on composite nanofluids as next-generation heat transfer medium

Journal of Thermal Analysis and Calorimetry - Nanocomposite is a nanotechnology-based multiphase, high-performance composite material having combination of properties, which has been emerged as one...     

Characteristics investigation on heat transfer growth of sonochemically synthesized ZnO-DW based nanofluids inside square heat exchanger

Journal of Thermal Analysis and Calorimetry - In recent decades, the growth of heat transfer using nanomaterials in the conventional base fluid has caught the attention of researchers...     

Two- and three-dimensional comparative study of heat transfer and pressure drop characteristics of nanofluids flow through a ventilated cubic cavity (part I: Newtonian nanofluids)

Journal of Thermal Analysis and Calorimetry - Through this paper, three-dimensional fluid flow and heat transfer of Al2O3 nanofluid within ventilated enclosures was taken into consideration....     

A review on molten-salt-based and ionic-liquid-based nanofluids for medium-to-high temperature heat transfer

Molten-salt-based nanofluids and ionic-liquid-based nanofluids are developed for thermal storage and heat transfer at relatively high temperatures, in the past few years. Preparation and stabilization techniques are briefly introduced firstly, and then, thermal properties, e.g., specific heat, thermal conductivity and viscosity, are summarized and discussed in detail. The properties are not only affected by the characteristics of nanomaterials and base fluids, but also affected by the synthesis method, such as the sonication intensity and duration. Some of the thermophysical property data are still incomplete, especially the thermal conductivity of molten-salt-based nanofluids, and properties of ionic-liquid-based nanofluids at high temperatures. While several literature works show that the Krieger–Dougherty model can well predict the viscosity, no general models for thermal conductivity and specific heat have been developed yet for both types of nanofluids.

     

Experimental investigation on the heat transfer performance of MHTHS using ethylene glycol-based nanofluids

Journal of Thermal Analysis and Calorimetry - Energy storage plays an important role in improving the applicability of a wide range of energy systems. Buildings could be considered as a desirable...     

Approaches for modelling of industrial energy systems: correlation of heat transfer characteristics between magnetohydrodynamics hybrid nanofluids and performance analysis of industrial length-scale heat exchanger

Journal of Thermal Analysis and Calorimetry - Numerical analysis is carried out on heat transfer performance of industrial-length double-tube heat exchanger, by using hybrid nanofluid as a coolant...     

Effect of conjugate heat transfer on the thermo-electro-hydrodynamics of nanofluids: entropy optimization analysis

Journal of Thermal Analysis and Calorimetry - We investigate, in this analysis, the entropy generation characteristics associated with the transport of nanofluid in a microfluidic channel under the...     

Review on the recent progress in the preparation and stability of graphene-based nanofluids

Journal of Thermal Analysis and Calorimetry - Graphene has attracted much attention from the science world because of its mechanical, thermal, and physical properties. Graphene nanofluid is well...     

Forced convection boiling heat transfer of freon-11 in a vertical annular passage

Forced convection boiling heat transfer coefficient of Freon-11 flowing upward through a vertical annular passage was measured. Heating element was a single inconel heating rod placed in the center of a stainless steel pipe. The range of temperature difference between the rod surface and the saturation temperature of the Freon was 2.2–14.5°C (3.9–26.1°F), and the range of the experimental heat transfer coefficient measured was 949–3419 watt/m²-°C (167.1–602 Btu/hr-ft²-°F). The measured heat transfer coefficients agreed very well with the values computed by using Chen's correlation equation for heat transfer, and the average standard deviation between these two values was ±4.03%.     

A review on heat transfer characteristics of cryogenic heat pipes

Journal of Thermal Analysis and Calorimetry - Heat pipes are broadly applied for thermal management of devices with high heat flux. Due to the dependency of their efficient operating range on the...     

Pool boiling enhancement with environmentally friendly surfactant additives

Boiling heat transfer is used in variety of industrial processes and applications, such as refrigeration, vapor cycle power generation, heat exchangers, petroleum refining, and chemical manufacturing. Enhancements in boiling heat transfer processes are critical for making these applications more energy efficient. The aim of this paper is to demonstrate the water pool boiling phenomena under the influence of environmentally friendly surfactant additives. The test setup used in this study has multiple benefits. First, the test setup enhances teaching in variety of classes through in-class demonstrations and student experiments. An experiment is described to allow the students to visualize and qualify different modes of boiling heat transfer. In addition, the test setup provides a platform for research in boiling enhancement. Using surfactant additives in boiling causes increased number of nucleation sites and decreased level of wall superheat. For determining surfactant effects, different concentrations of sodium lauryl sulfate (SLS), ECOSURF? EH-14, and ECOSURF? SA-9 are added to pure water and enhancement through surfactants is quantified. When times until boiling (liquid temperature reaches the boiling point) are measured, 17, 10.3, and 19.6 % lower times found (for SLS, EH-14, and SA-9, respectively) compared to pure water. Wall temperature reduction is measured for 50 ppm SLS 9.48 %, for 300 ppm EH-14 11.3 %, and for 200 ppm SA-9 10.43 %. It can be concluded from this study that a reduction in surface tension leads to a higher nucleation site density and more small bubbles on the boiling surface.