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# Convective Heat Transfer

Heat transfer by convection

• Library:
• Simscape / Foundation Library / Thermal / Thermal Elements

## Description

The Convective Heat Transfer block represents heat transfer by convection between two bodies by means of fluid motion. The Newton law of cooling describes the transfer,

`$Q=k\cdot A\cdot \left({T}_{A}-{T}_{B}\right),$`

where:

• Q is the heat flow.

• k is the convection heat transfer coefficient.

• A is the surface area.

• D is the distance between layers, that is, the thickness of material.

• TA and TB are the temperatures of the two bodies.

The heat transfer coefficient, k, can be either constant, which you specify by using the Heat transfer coefficient parameter, or variable, which you specify by using the physical signal at port K.

A and B are thermal conserving ports associated with the points between which the heat transfer by convection takes place. Because the block positive direction is from port A to port B, the heat flow is positive if it flows from A to B.

### Variables

To set the priority and initial target values for the block variables prior to simulation, use the Initial Targets section in the block dialog box or Property Inspector. For more information, see Set Priority and Initial Target for Block Variables.

Nominal values provide a way to specify the expected magnitude of a variable in a model. Using system scaling based on nominal values increases the simulation robustness. Nominal values can come from different sources, one of which is the Nominal Values section in the block dialog box or Property Inspector. For more information, see Modify Nominal Values for a Block Variable.

## Ports

### Input

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Input physical signal that controls the heat transfer coefficient. The signal saturates when the value is outside the minimum limit specified by the Minimum heat transfer coefficient block parameter.

#### Dependencies

To enable this port, set the Convection type parameter to `Variable`.

### Conserving

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Thermal conserving port associated with body A.

Thermal conserving port associated with body B.

## Parameters

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Whether to specify the heat transfer coefficient of the material as a block parameter or an input signal:

• `Constant` — The heat transfer coefficient, specified by the Heat transfer coefficient parameter, remains constant during simulation.

• `Variable` — The input physical signal at port K specifies the heat transfer coefficient, which can vary during simulation. The Minimum heat transfer coefficient parameter specifies the lower bound for the heat transfer coefficient.

Surface area of the heat transfer.

Convection heat transfer coefficient.

#### Dependencies

To enable this parameter, set Convection type to `Constant`.

Lower bound for the convection heat transfer coefficient. The input signal at port K saturates at this value to prevent the heat transfer coefficient from further decreasing.

#### Dependencies

To enable this parameter, set Convection type to `Variable`.

## Version History

Introduced in R2007b

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