Name: heat transfer calculations with conduction, convection
Uploaded: 2023-09-18T17:11:17.000Z
Duration: 1 min 20 s
Channel: JoVE

K12 Standards

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NC K-12 Science Standard Course of Study

9-12

Physical Science

Energy

PS.PSc.7.1

conduction-convection-and-radiation-problem-solving

Conduction, Convection and Radiation: Problem Solving

Uma parede de 13 cm de espessura com uma área de 100 m2 e condutividade térmica de 1,5 W/mK separa uma sala da atmosfera externa, que está a 3 graus Celsius.
A superfície externa da parede está a 10 graus Celsius e sua emissividade é de 0,8. Se o coeficiente de transferência de calor por convecção for 15 W/m2K , encontre a taxa total de perda de calor para o ambiente. Além disso, calcule a temperatura da superfície interna da parede.
Aqui, todos os três mecanismos de transferência de calor estão envolvidos. O calor é transferido da superfície interna para a externa da parede por condução, enquanto a perda de calor para o ambiente ocorre devido à convecção e radiação.
A taxa de perda de calor por convecção depende do gradiente de temperatura, área de superfície e coeficiente de transferência de calor.
Assim, a perda total de calor para o ambiente devido à convecção e radiação pode ser calculada como 13,27 x 103 W.
Empregando a conservação de energia e substituindo os termos da equação do calor, a temperatura da superfície interna da parede pode ser calculada.

<ol>
	<li>OpenStax. (2019). Física Universitária Vol. 2. [Versão Web]. Obtido de <a href="https://openstax.org/books/university-physics-volume-2/pages/1-6-mechanisms-of-heat-transfer">https://openstax.org/books/university-physics-volume-2/pages/1-6-mechanisms-of-heat-transfer</a></li>
</ol>

condução, convecção e radiação: resolução de problemas

Existem três métodos pelos quais a transferência de calor pode ocorrer: condução, convecção e radiação. Cada método tem características únicas e interessantes, mas todos eles apresentam duas coisas em comum: eles transferem calor exclusivamente por causa da diferença de temperatura, e quanto maior a diferença de temperatura, mais rápida é a transferência de calor.

Para resolver um problema relacionado à transferência de calor, em primeiro lugar, a situação precisa ser examinada para determinar o tipo de transferência de calor envolvida. Essa transferência pode ser por condução, convecção, radiação ou as três. O segundo passo é identificar e anotar as quantidades desconhecidas no problema. Uma lista pode ser preparada com o que é dado ou o que pode ser inferido do problema, conforme apresentado, ou seja, as quantidades conhecidas, seguido pela resolução da equação apropriada para a quantidade a ser determinada.

Para a transferência de calor por condução, a seguinte equação deve ser utilizada:

<img alt="Equation1" src="/files/ftp_upload/14166/14166_Equation_1.svg" style="text-align: center; height: 46px;" />

Para convecção, a taxa de perda de calor depende do gradiente de temperatura, área de superfície e coeficiente de transferência de calor.

<img alt="Equation2" src="/files/ftp_upload/14166/14166_Equation_2.svg" style="text-align: center; height: 18px;" />

A seguinte equação fornece a taxa de transferência de calor líquida para radiação:

<img alt="Equation3" src="/files/ftp_upload/14166/14166_Equation_3.svg" style="text-align: center; height: 25px;" />

Substituir as quantidades conhecidas juntamente com suas unidades na equação apropriada e resolvê-la numericamente fornece a solução correta.

Condução, Convecção e Radiação: Resolução de Problemas

Existem três métodos pelos quais a transferência de calor pode ocorrer: condução, convecção e radiação. Cada método tem um método único e interessante ...

Education

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Physics

Física

Unit 1

Unidade 1

Temperature and Heat

Temperatura e Calor

KEY TERMS AND CONCEPTS

TERMOS-CHAVE E CONCEITOS

heat transfer calculations with conduction, convection

Heat transfer calculations with conduction and convection use the temperature difference to find the rate of heat flow. Radiation can also be part of the process. The main idea is that heat moves only because one area is hotter than another, and a larger temperature difference leads to faster transfer.

To solve a heat transfer problem, first identify the type of transfer involved. It may be conduction, convection, radiation, or a combination of all three. Next, write down the unknown quantities and sort the given information from the problem statement.

After the known values are listed, choose the correct equation for the type of heat transfer. Use the conduction equation for heat flow through materials. For convection, the rate of heat loss depends on the temperature gradient, the surface area, and the heat transfer coefficient. For radiation, use the equation for net heat transfer rate.

Finally, substitute the known quantities and their units into the selected equation. Solve the equation numerically to find the answer. This method helps students work through heat transfer problems in a clear, step-by-step way.

Heat Transfer Calculations with Conduction, Convection

heat-transfer-calculations-with-conduction-convection

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conduction, convection and radiation: problem solving

Heat transfer calculations with conduction and convection use the temperature difference to find the rate of heat flow. Radiation can also be part of the process. The main idea is that heat moves only because one area is hotter than another, and a larger temperature difference leads to faster transfer. To solve a heat transfer problem, first identify the type of transfer involved. It may be conduction, convection, radiation, or a combination of all three. Next, write down the unknown...

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Learn how to solve heat transfer problems by identifying conduction, convection, or radiation, choosing the right equation, and calculating the unknowns.

Heat Transfer Calculations with Conduction, Convection | JoVE K12

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PS.PSc.7.2

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Positive, Negative, and Zero Work

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PS.PSc.7.3

Power

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Power Expended by a Constant Force

The relationship between work done and the time taken to do it can be explained using the concept of power. For example, several sprinters in a race may ...

Construct an explanation to infer the relationship between work and power, both quantitatively and qualitatively.

PS.PSc.7.4

Analyze energy transfers and transformations within a mechanical system.

Heat Transfer Calculations with Conduction, Convection

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