Engee documentation

Convective Heat Transfer

Convective heat transfer.

blockType: AcausalFoundation.Thermal.Elements.Convection

controlled convective heat transfer

Convective Heat Transfer

Path in the library:

/Physical Modeling/Fundamental/Thermal/Elements/Convective Heat Transfer

convective heat transfer 1

Variable Convective Heat Transfer

Path in the library:

/Physical Modeling/Fundamental/Thermal/Elements/Variable Convective Heat Transfer

Description

Block Convective Heat Transfer It is a convective transfer of heat between two bodies, that is, heat transfer through the movement of matter. The process is described by the Newton-Richman law:

where

  • — heat flow;

  • — heat transfer coefficient;

  • — surface area;

  • and — temperatures of two bodies .

A and B are thermal ports corresponding to different bodies. The heat flow is positive if it flows from A to B.

Ports

Conserving

# A — Body A
heat

Details

Thermal port corresponding to body A.

Program usage name

port_a

# B — body B
heat

Details

Thermal port corresponding to body B.

Program usage name

port_b

Input

# K — heat transfer coefficient control signal, W/(K*m2)
scalar

Details

The input signal for controlling the heat transfer coefficient. The signal value cannot fall below the limit set by the parameter Minimum heat transfer coefficient. A signal less than this value is equated to Minimum heat transfer coefficient.

Dependencies

To use this port, set the parameter Convection type value Variable.

Data types

Float64
Complex numbers support

I don’t

Parameters

Parameters

# Convection type — type of heat transfer coefficient
Fixed | Variable

Details

Type of heat transfer coefficient:

  • Fixed — the heat transfer coefficient set by the parameter Heat transfer coefficient, remains constant during simulation.

  • Variable — the input signal on port K sets the heat transfer coefficient, which can change during simulation. Parameter Minimum heat transfer coefficient sets the lower limit of the heat transfer coefficient.

Values

Fixed | Variable
Default value

—
Program usage name

type
Evaluatable

No

# Area — heat exchange area
m^2 | um^2 | mm^2 | cm^2 | km^2 | in^2 | ft^2 | yd^2 | mi^2 | ha | ac

Details

Heat exchange surface area.

Units

m^2 | um^2 | mm^2 | cm^2 | km^2 | in^2 | ft^2 | yd^2 | mi^2 | ha | ac
Default value

1e-4 m^2
Program usage name

area
Evaluatable

Yes

# Heat transfer coefficient — heat transfer coefficient
W/(m^2*K) | Btu_IT/(hr*ft^2*deltadegR)

Details

Heat transfer coefficient.

Dependencies

To use this parameter, set for the parameter Convection type meaning Fixed.

Units

W/(m^2*K) | Btu_IT/(hr*ft^2*deltadegR)
Default value

20.0 W/(m^2*K)
Program usage name

h
Evaluatable

Yes

# Minimum heat transfer coefficient — the lower limit of the heat transfer coefficient
W/(m^2*K) | Btu_IT/(hr*ft^2*deltadegR)

Details

The lower limit of the convective heat transfer coefficient.

The input signal on port K is saturated at this value to prevent further reduction of the heat transfer coefficient.

Dependencies

To use this parameter, set for the parameter Convection type meaning Variable.

Units

W/(m^2*K) | Btu_IT/(hr*ft^2*deltadegR)
Default value

0.001 W/(m^2*K)
Program usage name

h_min
Evaluatable

Yes

Examples