Numerical investigation on heat transfer rate from the outside environment into the electronic compartment of the measurement‐while‐drilling tools

Heat Transfer ◽  
2021 ◽  
Author(s):  
Wenkai Gao ◽  
Ke Liu ◽  
Xiurong Dou ◽  
Liang Zhang ◽  
Song Tang
2018 ◽  
Vol 37 ◽  
pp. 121-129 ◽  
Author(s):  
Goutam Saha

A numerical investigation is carried out to observe the augmentation of heat transfer because of the presence of TiO2 nanofluid inside a sinusoidal cavity. In this study, upper and lower walls of the cavity are considered adiabatic, higher and lower temperature are maintained at left and right vertical walls respectively. Also, 2D contour of velocity and temperature with average heat transfer rate are presented and discussed. Our findings show that augmentation of heat transfer is feasible with the increase of concentrations of nanoparticles.GANIT J. Bangladesh Math. Soc.Vol. 37 (2017) 121-129


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Sami D. Salman ◽  
Abdul Amir H. Kadhum ◽  
Mohd S. Takriff ◽  
Abu Bakar Mohamad

Numerical investigation of the heat transfer and friction factor characteristics of a circular fitted with V-cut twisted tape (VCT) insert with twist ratio (y=2.93) and different cut depths (w=0.5, 1, and 1.5 cm) were studied for laminar flow using CFD package (FLUENT-6.3.26). The data obtained from plain tube were verified with the literature correlation to ensure the validation of simulation results. Classical twisted tape (CTT) with different twist ratios (y=2.93, 3.91, 4.89) were also studied for comparison. The results show that the enhancement of heat transfer rate induced by the classical and V-cut twisted tape inserts increases with the Reynolds number and decreases with twist ratio. The results also revealed that the V-cut twisted tape with twist ratioy=2.93and cut depthw=0.5 cm offered higher heat transfer rate with significant increases in friction factor than other tapes. In addition the results of V-cut twist tape compared with experimental and simulated data of right-left helical tape inserts (RLT), it is found that the V-cut twist tape offered better thermal contact between the surface and the fluid which ultimately leads to a high heat transfer coefficient. Consequently, 107% of maximum heat transfer was obtained by using this configuration.


Author(s):  
Bernardo Buonomo ◽  
Anna di Pasqua ◽  
Oronzio Manca ◽  
Sergio Nappo ◽  
Jawali C. Umavathi

Abstract In this paper a numerical investigation has been accomplished to study the thermal and fluid dynamic behavior of a tubular heat exchanger partially filled with metal foam. The Darcy – Brinkman - Forchheimer model and the local thermal non-equilibrium hypothesis (LTNE) for the thermal energy are used to execute two-dimensional analyses on the aluminum foam heat exchanger. The heat exchanger is studied for several air flow rates and a fixed temperature on the surface tube. The results are shown in terms of heat transfer rate and pumping power. Furthermore, the ratios in terms of heat transfer rate and pumping power are given for the two different configurations (partially and totally filled) in order to find the most convenient scheme. Furthermore, the temperature and pressure fields are evaluated. a comparison among the different thickness of the metal foam between two adjacent tubes and the fully filled configuration is given. The results show that the smaller value of metal foam thickness is characterized by a better performance.


Author(s):  
Manimegalai Kavarthalai ◽  
Vimala Ponnuswamy

A theoretical study of a squeezing ferro-nanofluid flow including thermal effects is carried out with application to bearings and articular cartilages. A representational geometry of the thin layer of a ferro-nanofluid squeezed between a flat rigid disk and a thin porous bed is considered. The flow behaviours and heat transfer in the fluid and porous regions are investigated. The mathematical problem is formulated based on the Neuringer–Rosensweig model for ferro-nanofluids in the fluid region including an external magnetic field, Darcy law for the porous region and Beavers–Joseph slip condition at the fluid–porous interface. The expressions for velocity, fluid film thickness, contact time, fluid flux, streamlines, pathlines, mean temperature and heat transfer rate in the fluid and porous regions are obtained by using a perturbation method. An asymptotic solution for the fluid layer thickness is also presented. The problem is also solved by a numerical method and the results by asymptotic analysis, perturbation and numerical methods are obtained assuming a constant force squeezing state and are compared. It is shown that the results obtained by all the methods agree well with each other. The effects of various parameters such as Darcy number, Beavers–Joseph constant and magnetization parameter on the flow behaviours, contact time, mean temperature and heat transfer rate are investigated. The novel results showing the impact of using ferro-nanofluids in the two applications under consideration are presented. The results under special cases are further compared with the existing results in the literature and are found to agree well.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3711
Author(s):  
Asifa ◽  
Talha Anwar ◽  
Poom Kumam ◽  
Zahir Shah ◽  
Kanokwan Sitthithakerngkiet

In this modern era, nanofluids are considered one of the advanced kinds of heat transferring fluids due to their enhanced thermal features. The present study is conducted to investigate that how the suspension of molybdenum-disulfide (MoS2) nanoparticles boosts the thermal performance of a Casson-type fluid. Sodium alginate (NaAlg) based nanofluid is contained inside a vertical channel of width d and it exhibits a flow due to the movement of the left wall. The walls are nested in a permeable medium, and a uniform magnetic field and radiation flux are also involved in determining flow patterns and thermal behavior of the nanofluid. Depending on velocity boundary conditions, the flow phenomenon is examined for three different situations. To evaluate the influence of shape factor, MoS2 nanoparticles of blade, cylinder, platelet, and brick shapes are considered. The mathematical modeling is performed in the form of non-integer order operators, and a double fractional analysis is carried out by separately solving Caputo-Fabrizio and Atangana-Baleanu operators based fractional models. The system of coupled PDEs is converted to ODEs by operating the Laplace transformation, and Zakian’s algorithm is applied to approximate the Laplace inversion numerically. The solutions of flow and energy equations are presented in terms of graphical illustrations and tables to discuss important physical aspects of the observed problem. Moreover, a detailed inspection on shear stress and Nusselt number is carried out to get a deep insight into skin friction and heat transfer mechanisms. It is analyzed that the suspension of MoS2 nanoparticles leads to ameliorating the heat transfer rate up to 9.5%. To serve the purpose of achieving maximum heat transfer rate and reduced skin friction, the Atangana-Baleanu operator based fractional model is more effective. Furthermore, it is perceived that velocity and energy functions of the nanofluid exhibit significant variations because of the different shapes of nanoparticles.


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