Natural, Mixed, and Forced Convection in Nanofluid

Ganji, D.D.; Kachapi, Sayyid H. Hashemi

doi:10.1016/b978-0-323-35237-6.00006-6

Cited by 3 publications

(3 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[18b] Poiseuille flow (also called convective flow) is the pressure-induced pore flow model generally adopted to describe the transport in a capillary or a porous medium. [99] In Poiseuille flow when the pores are very small and the mean free path of the gases and ions is larger than the pore diameter, collisions with the pore will occur and the lighter molecules will then preferentially pass through the membrane.…”

Section: Transport Mechanismmentioning

confidence: 99%

Atom‐Thick Membranes for Water Purification and Blue Energy Harvesting

Pakulski

Czepa

Buffa

et al. 2019

Adv Funct Materials

View full text Add to dashboard Cite

Membrane-based processes such as water purification and harvesting of osmotic power deriving from the difference in salinity between seawater and freshwater, are two strategic research fields holding great promises for overcoming critical global issues like the world growing energy demand, the climate change and the access to clean water. Ultrathin membranes based on two-dimensional materials (2DMs) are particularly suitable for highly selective separation of ions and effective generation of blue energy, because of their unique physicochemical properties and novel transport mechanisms occurring at the nano-and sub-nanometer length scale. However, due to the relatively high costs of fabrication compared to traditional porous membrane materials, their technological transfer towards large-scale applications still remains a great challenge. Herein, we present an overview of the current state-of-the-art in the development of ultrathin membranes based on 2DMs for osmotic power generation and water purification. We discuss several synthetic routes to produce atomically-thin membranes with controlled porosity and we describe in detail their performances, with a particular emphasis on pressure retarded osmosis and reversed electrodialysis methods. In the last section, outlooks and current limitations as well as viable future developments in the field of 2DMs membranes are provided.3

show abstract

Section: Transport Mechanismmentioning

confidence: 99%

Atom‐Thick Membranes for Water Purification and Blue Energy Harvesting

Pakulski

Czepa

Buffa

et al. 2019

Adv Funct Materials

View full text Add to dashboard Cite

show abstract

“…Mixed convection flows, which are also known as combined free and forced convection flows, occur in many technological and industrial applications and are driven by both external force and density difference 1 . In a reactor core, during the accident conditions, the passive decay heat removal system in the reactor becomes active, throughout the long‐term cooling phase, circulation of the coolant in fuel assembly is driven by buoyancy, and a mixed convection regime may occur under such conditions with a low flow rate 2 .…”

Section: Introductionmentioning

confidence: 99%

Numerical investigation of turbulent mixed convection flow and heat transfer characteristics of 2 × 2 subchannels with spacer grids

Long

Yang

et al. 2023

Energy Science & Engineering

View full text Add to dashboard Cite

In turbulent mixed convection conditions, flow and heat transfer can deteriorate under specific conditions, thus affecting the performance of the safety of the system, which could imperil the safety of the nuclear reactor. In this paper, by analyzing the velocity, temperature distributions, and other thermal‐hydraulic parameters, the steady‐state computational fluid dynamics approach with the SST k–ω turbulence model used in this study was verified. Then, flow and heat transfer characteristics in turbulent mixed convection inside 2 × 2 subchannels with and without spacer grids were investigated. The results showed that the velocity profiles were distorted and the heat transfer capacity was impaired due to the influence of buoyancy. The Nusselt number ratio (Nu/Nuf) between turbulent mixed convection and forced convection increased with the increase of Reynolds number (Re) until unity but decreased with the increases of Grashof number (Gr) and Buoyancy parameter (Bo*).

show abstract

“…Ramachandran et al (1988) conducted a study related to the mixed convection in stagnation point flow. The mixed convection flow is a combination of forced and free convection flows that arise in many industrial processes such as in the cooling process of electronic devices and nuclear reactors, solar receivers and in heat exchangers (Ganji and Kachapi, 2015). This flow, which was first investigated by Merkin (1969), was characterized by the buoyancy parameter l = Gr/Re n (in his paper) where Gr is the Grashof number, Re is the Reynolds number and n(> 0) is a constant that depends on the surface heating conditions and flow configuration (Pop and Ingham, 2001).…”

mentioning

confidence: 99%

Mixed convective stagnation point flow of a hybrid nanofluid toward a vertical cylinder

Khashi’ie

Arifin

Merkin

et al. 2021

HFF

View full text Add to dashboard Cite

Purpose The purpose of this paper is to numerically analyze the stagnation point flow of Cu-Al2O3/water hybrid nanofluid with mixed convection past a flat plate and circular cylinder. Design/methodology/approach The similarity equations that reduced from the boundary layer and energy equations are solved using the bvp4c solver. The duality of solutions is observed within the specific range of the control parameters, namely, mixed convection parameter λ, curvature parameter γ and nanoparticles volumetric concentration ϕ1 for alumina, while for copper ϕ2. The stability analysis is also designed to justify the particular solutions’ stability. Additionally, the idea to obtain the solution for large value of λ and γ is also presented in this paper. Findings Two solutions exist in opposing and assisting flows up to a critical value λc where λc lies in the opposing region. An upsurge of the curvature parameter tends to extend the critical value (delay the separation process), whilst increase the heat transfer performance of the working fluid. Meanwhile, the application of hybrid Cu-Al2O3/water nanofluid also can decelerate the separation of laminar boundary layer flow and produce higher heat transfer rate than the Cu–water nanofluid and pure water. Originality/value The results are new and original. This study benefits to the other researchers, specifically in the observation of the fluid flow characteristics and heat transfer rate of the hybrid nanofluid. Also, this paper features with the mathematical formulation for the solution with large values of λ and γ.

show abstract

Natural, Mixed, and Forced Convection in Nanofluid

Cited by 3 publications

References 44 publications

Atom‐Thick Membranes for Water Purification and Blue Energy Harvesting

Atom‐Thick Membranes for Water Purification and Blue Energy Harvesting

Numerical investigation of turbulent mixed convection flow and heat transfer characteristics of 2 × 2 subchannels with spacer grids

Mixed convective stagnation point flow of a hybrid nanofluid toward a vertical cylinder

Contact Info

Product

Resources

About