scholarly journals A Numerical Study on the Effects of the Geometry and Location of an Inserted Wire on Methane–Air Flames in a Micro–Burner

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 93
Author(s):  
Jalal Zarvandi ◽  
Mohammadreza Baigmohammadi ◽  
Sadegh Tabejamaat
Keyword(s):  
Temperature Distribution ◽  
Outer Surface ◽  
Numerical Study ◽  
Chemical Species ◽  
Maximum Temperature ◽  
Wall Effects ◽  
Linear Effects ◽  
Two Parameters ◽  
Shed Light ◽  
Do So

The effects of the diameter and location of an inserted wire on methane–air flame characteristics in a micro-burner, with a backward-facing step, were investigated numerically. Our goal was to shed light on the parameters that the authors had not already considered in the previous study. To do so, the effects of the studied parameters on the flame location and distribution of temperature, H, and OH species, were scrutinized. It was shown that increasing the inserted wire’s diameter and relocating the inserted wire towards the outlet had polynomial and linear effects on the flame location in the burner, respectively. Although changing these two parameters did not have any obvious effects on the maximum temperature of the auxiliary axis in the burner or the external wall, effects on the peak values of the hot-flame critical chemical species of OH and H were recognized. Furthermore, it was shown that the temperature distribution on the outer surface of the burner was more influenced by the wire’s axial location in the burner, rather than the wire’s diameter. This effect may be of interest for designing micro-TPVs or micro-TEGs.

Numerical Simulation of Turbulent Heat Transfer on a Rotating Disk With an Impinging Jet

2010 ◽  
Author(s):  
M. H. Saidi ◽  
H. Karrabi ◽  
H. B. Avval ◽  
A. Asgarshamsi
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
Rotating Disk ◽  
Turbulent Heat Transfer ◽  
Maximum Temperature ◽  
Turbulent Heat ◽  
Cooling Process ◽  
Maximum Temperature Difference

A numerical study has been earned out to investigate the fluid flow structure and convective heat transfer due to a circular jet impinging on a rotating disk. The temperature distribution and convection heat transfer coefficient on the disk are calculated. Flow is considered to be steady, incompressible and turbulent. k-ε RNG model is used to model the turbulent flow. Two new criteria are introduced and used to evaluate the performance of cooling process which are maximum temperature difference on the disk and the average temperature of the disk. The first parameter shows the uniformity of temperature distribution in the disk and the second shows the effect of both thermo physical properties of the disk material and cooling process. In order to verify the numerical approach, results have been compared with the experimental data which shows a good agreement.

New Method of Flow Maldistribution Mitigation in Parallel Microchannel Heat Sink

2017 ◽  
Author(s):  
Vikas Yadav ◽  
Ritunesh Kumar
Keyword(s):  
Temperature Distribution ◽  
Heat Sink ◽  
Numerical Study ◽  
Three Dimensional ◽  
Heat Sinks ◽  
Maximum Temperature ◽  
Computational Domain ◽  
Microelectronic Devices ◽  
Volume Method ◽  
Flow Maldistribution

Microchannel heat sinks (MCHS) are explored as integrated cooling option in diversified applications ranging from microelectronic devices to nuclear reactors. Parallel channel MCHS suffers from the problem of flow maldistribution in channels. The phenomenon of flow maldistribution causes undesired effects such as non-uniform temperature distribution, increase in base maximum temperature and drop in MCHS performance. In the present single phase numerical study; flow maldistribution in vertical supply MCHS has been estimated by taking entire heat sink as computational domain. Three-dimensional governing equations for both fluid flow and energy transfer are solved by finite volume method. A novel heat sink design by splitting the inlet flow in two equal parts has been proposed to effectively reduce flow maldistribution problem in MCHS. Results of velocity distribution, temperature distribution of fluid and overall thermal performance of proposed MCHS are compared with the conventional MCHS design. Proposed scheme helps in reducing flow maldistribution problem significantly (∼55%) as compared to conventional MCHS.

Numerical Study of the Effect of a Biodiesel on the Cylinder Liner of Compression Ignition Engine

2017 ◽  
Author(s):  
Chidiebere F. Nwaiwu ◽  
Olisaemeka C. Nwufo ◽  
Johnson O. Igbokwe ◽  
Nnamdi V. Ogueke ◽  
Emmanuel E. Anyanwu
Keyword(s):  
Temperature Distribution ◽  
Diesel Fuel ◽  
Cylinder Head ◽  
Numerical Study ◽  
Cylinder Liner ◽  
Maximum Temperature ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Liner Material ◽  
Head Section

A numerical study of temperature distribution in the cylinder liner of biodiesel-powered compression ignition engine is presented. The mathematical model equations developed were based on heat transfers in the cylinder liner and subsequently transformed using the finite difference method. Numerical solutions were obtained from computer codes written in MATLAB programming language. A biodiesel produced from Nigerian physic nut oil was used in the study. The result was compared with that obtained for conventional diesel fuel. The results revealed that the cylinder head section of the liner material presented higher temperature distribution compared to the oil sump section of the liner. Over a twelve-minute time range, the liner attained steady state with Jatropha-based biodiesel, recording a maximum temperature of 873.1°C. Conventional diesel recorded the lower temperature of 784.3°C. Results also showed that the cylinder head section of the liner material closest to the combustion chamber experienced the greatest temperature rise in comparison to other parts of the liner. These results show that though there are lots of publications confirming that a compression ignition engine previously running on diesel fuel can run on biodiesel fuel or its blend with diesel, there is a need for a further critical study on the development of engine parts like the cylinder liner.

De splitsing van de Belgische Socialistische Partij. Twee verklarende documenten

2008 ◽  
Vol 67 (2) ◽  
pp. 99-114
Author(s):  
Pieter-Jan Van Bosstraeten
Keyword(s):  
Socialist Party ◽  
French Speaking ◽  
History Of ◽  
Post War ◽  
Shed Light ◽  
Do So

Op 11 oktober 1978 splitste de Belgische Socialistische Partij zich als laatste van de drie unitaire partijen op in twee autonome partijen. Langs Franstalige zijde werd éénzijdig de Parti Socialiste opgericht, twee jaar later volgde de Socialistische Partij. De splitsing vormde het eindpunt van een lange en bewogen geschiedenis van de socialistische eenheidspartij.Ondanks het feit dat heel wat auteurs reeds een licht hebben geworpen op de belangrijkste gebeurtenis uit de na-oorlogse geschiedenis van de BSP, is het antwoord op de vraag naar de oorzaken van de splitsing vrij eenduidig. Overwegend wordt aangenomen dat de splitsing van de BSP het gevolg is van een moeilijke samenwerking in het kader van het communautaire dossier. Andere oorzaken worden amper aangehaald, of onvoldoende verduidelijkt. Tevens wordt slechts het politiek-tactische aspect van het communautaire dossier uitvoerig besproken. In de bestaande literatuur wordt zo goed als nergens dieper ingegaan op de inhoudelijke elementen die binnen de partij problemen teweegbrachten.Onderzoek van twee cruciale documenten heeft de mogelijkheid geboden het verhaal van de splitsing beter te reconstrueren. Daarbij is gebleken dat de splitsing van de partij in een ruimer kader dient te worden geïnterpreteerd dan het communautaire dossier. Aan de splitsing van de partij ging een lang proces van autonomisering en vleugelvorming vooraf. Bovendien werd aangetoond dat de problematiek inzake het Egmont-Stuyvenbergpact niet de enige directe oorzaak vormde voor de splitsing van de partij, in de periode 1977-1978. Enkele andere oorzaken hebben daartoe eveneens bijgedragen.________The division of the Belgian Socialist Party. Two explanatory documentsOn 11 October 1978 the Belgian Socialist Party divided into two autonomous parties, the last of the three unitary parties to do so. First the French speaking section unilaterally founded the ‘Parti Socialiste’, two years later the ‘Socialistische Partij’ followed. The division constituted the termination of the long and eventful history of the socialist unitary party.In spite of the fact that many authors have already shed light on the most important event from the post-war history of the BSP, the answer to the question about the causes for the division are fairly unequivocal. The majority of opinions favour the view that the division of the BSP was the consequence of the difficulty of collaborating within the framework of the community dossier. Other causes are hardly cited, or insufficiently elucidated. Moreover only the politico-tactical aspect of the community dossier is discussed in detail. The existing literature hardly ever carries out a more thorough examination of the intrinsic elements that caused problems within the party.The investigation of the two crucial documents has offered the opportunity to provide a better reconstruction of the division. This showed that the division of the party should be interpreted within a larger framework than the community dossier alone. A long process of autonomisation and the formation of political wings preceded the division of the party. It also demonstrated that the issues concerning the Egmont-Stuyvenberg pact were not the only direct cause for the division of the party, during the period 1977-1978. There were several other causes that also contributed to this division.

scholarly journals Numerical study on temperature distribution of tunnel structure in fires

2021 ◽  
Vol 25 ◽  
pp. 100874
Author(s):  
Xin Xu ◽  
Guoqing Zhu ◽  
Xiaojin Zhang ◽  
Guoqiang Chai ◽  
Tianwei Chu
Keyword(s):  
Temperature Distribution ◽  
Numerical Study ◽  
Tunnel Structure

Lawful Remedy or Illegal Response? Resolving the Issue of Foreign Subsidization Under WTO Law

2021 ◽  
pp. 1-24
Author(s):  
Victor Crochet ◽  
Marcus Gustafsson
Keyword(s):  
European Union ◽  
World Trade Organization ◽  
World Trade ◽  
The European Union ◽  
Fair Competition ◽  
Trade Law ◽  
International Trade Law ◽  
The World ◽  
Shed Light ◽  
Do So

Abstract Discontentment is growing such that governments, and notably that of China, are increasingly providing subsidies to companies outside their jurisdiction, ‘buying their way’ into other countries’ markets and undermining fair competition therein as they do so. In response, the European Union recently published a proposal to tackle such foreign subsidization in its own market. This article asks whether foreign subsidies can instead be addressed under the existing rules of the World Trade Organization, and, if not, whether those rules allow States to take matters into their own hands and act unilaterally. The authors shed light on these issues and provide preliminary guidance on how to design a response to foreign subsidization which is consistent with international trade law.

Interaction between patient and health professional

2021 ◽  
Vol 16 (3) ◽  
Author(s):  
Anita Naemi Holm
Keyword(s):  
Health Professional ◽  
Health Sector ◽  
Richard Rorty ◽  
Cultural Encounter ◽  
Theoretical View ◽  
German Philosopher ◽  
The One ◽  
Hans Georg Gadamer ◽  
Shed Light ◽  
Do So

This article presents a theoretical view on culturally embedded thinking and action in encounters between patient and health professional. A key point of the analysis indicates that a highly efficient health sector may entail an implicit duality: on the one hand, the health professional can and often must relate pragmatically to the patient in order to solve problems and do so quickly, while on the other, the professional may be personally challenged when embedded cultural thinking leads to conflicts or dilemmas. This means that a purely pragmatic perspective will be challenged when such conflicts arise. The article looks at interrelated concepts such as ‘culture’, ‘prejudice’ and ‘meaning’ in order to shed light on the presuppositions that are brought into the cultural encounter between patient and health professional. This kind of analysis will hopefully contribute to a raised awareness of what is actually – apart from pragmatic problem solving – going on in such encounters. The conceptual framework used in this article primarily draws on the German philosopher Hans-Georg Gadamer, which is contrasted with the pragmatic perspective from the American philosopher Richard Rorty.

Electromagnetic performance and thermal analysis of a novel permanent magnet fluxed-switching coupler

2021 ◽  
pp. 1-18
Author(s):  
Lezhi Ye ◽  
Yulong Zhang ◽  
Mingguang Cao
Keyword(s):  
Temperature Distribution ◽  
Permanent Magnet ◽  
Permanent Magnets ◽  
Three Dimensional ◽  
Load Condition ◽  
Maximum Load ◽  
Maximum Temperature ◽  
The Novel ◽  
Transient Field ◽  
Three Dimensional Finite Element

To solve the problem of complex operating device and permanent magnets (PMs) demagnetization at high temperature, a new type of permanent magnet fluxed-switching coupler (PMC) with synchronous rotating adjuster is proposed. Its torque can be adjusted by rotating a switched flux angle between the adjuster and PMs along the circumferential direction. The structural feature and working principle of the PMC are introduced. The analytical model of the novel PMC was established. The torque curves are calculated in transient field by using the three-dimensional finite element method (3-D FEM). The temperature distribution of the novel PMC under rated condition is calculated by 3-D FEM, and the temperature distribution of the PM is compared with that of the conventional PMC. The simulation and test results show that the maximum temperature of copper disc and PM of the novel PMC are 100 °C and 48 °C respectively. The novel PMC can work stably for a long time under the maximum load condition.

Effect of Periodic Imposed Heat Flux on Three-Dimensional Natural Convection in a Partially Heated Cubical Enclosure

2016 ◽  
Vol 831 ◽  
pp. 83-91
Author(s):  
Lahoucine Belarche ◽  
Btissam Abourida
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Numerical Study ◽  
Control Volume ◽  
Vertical Wall ◽  
Three Dimensional ◽  
Maximum Temperature ◽  
Cubical Enclosure ◽  
Simplec Algorithm ◽  
Volume Method

The three-dimensional numerical study of natural convection in a cubical enclosure, discretely heated, was carried out in this study. Two heating square sections, similar to the integrated electronic components, are placed on the vertical wall of the enclosure. The imposed heating fluxes vary sinusoidally with time, in phase and in opposition of phase. The temperature of the opposite vertical wall is maintained at a cold uniform temperature and the other walls are adiabatic. The governing equations are solved using Control volume method by SIMPLEC algorithm. The sections dimension ε = D / H and the Rayleigh number Ra were fixed respectively at 0,35 and 106. The average heat transfer and the maximum temperature on the active portions will be examined for a given set of the governing parameters, namely the amplitude of the variable temperatures a and their period τp. The obtained results show significant changes in terms of heat transfer, by proper choice of the heating mode and the governing parameters.

scholarly journals Research on Influence of Different Simulation Methods of Bypass Flow in Thermal Hydraulic Analysis on Temperature Distribution in HTR-10

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Shiyan Sun ◽  
Youjie Zhang ◽  
Yanhua Zheng
Keyword(s):  
Temperature Distribution ◽  
Reactor Core ◽  
Flow Distribution ◽  
Maximum Temperature ◽  
Flow Ratio ◽  
Hydraulic Analysis ◽  
Bypass Flow ◽  
Pebble Bed ◽  
The Core ◽  
Thermal Hydraulic Analysis

In pebble-bed high temperature gas-cooled reactor, gaps widely exist between graphite blocks and carbon bricks in the reactor core vessel. The bypass helium flowing through the gaps affects the flow distribution of the core and weakens the effective cooling of the core by helium, which in turn affects the temperature distribution and the safety features of the reactor. In this paper, the thermal hydraulic analysis models of HTR-10 with bypass flow channels simulated at different positions are designed based on the flow distribution scheme of the original core models and combined with the actual position of the core bypass flow. The results show that the bypass coolant flowing through the reflectors enhances the heat transfer of the nearby components efficiently. The temperature of the side reflectors and the carbon bricks is much lower with more side bypass coolant. The temperature distribution of the central region in the pebble bed is affected by the bypass flow positions slightly, while that of the peripheral area is affected significantly. The maximum temperature of the helium, the surface, and center of the fuel elements rises as the bypass flow ratio becomes larger, while the temperature difference between them almost keeps constant. When the flow ratio of each part keeps constant, the maximum temperature almost does not change with different bypass flow positions.

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