Engee documentation

Heatsink

Heat removal to the environment from power semiconductor devices.

blockType: AcausalElectricPowerSystems.Passive.Thermal.Heatsink

heatsink

Path in the library:

/Physical Modeling/Electrical/Passive/Thermal/Heatsink

Description

Block Heatsink simulates a radiator that dissipates heat from power semiconductor devices. The heat from the housing passes through the fins and is dissipated to ambient temperature due to convection. The description of the unit assumes that the environment is a working fluid.

In the block, it is possible to set parameters using tabular heat transfer characteristics or based on the geometry of the radiator using empirical formulas to describe convection. If for the parameter Convection the value is set Forced - specify flow speed, then it is necessary to set the flow rate through the input port V.

Parameterization: tabular characteristics

To parameterize the block Heatsink using the tabular characteristics, set the parameter Parameterization meaning Datasheet and set the parameter values Vector of temperature rises above ambient, T and Corresponding heat dissipated to ambient, Q_TLU1(T).

If the forced convection mode is selected for the simulation (parameter Convection it matters Forced - specify flow speed), then you need to set the parameter values Vector of temperature rises above ambient, T and Corresponding heat dissipated to ambient, Q_TLU2(T, v).

Parameterization: tabular values of convective heat transfer coefficients and rib efficiency

Set for the parameter Parameterization meaning Tabulated convection and fin efficiency to parameterize the block Heatsink based on two parameters:

  • the coefficient of convective heat transfer as a function of the fluid flow rate (for forced convection) and the difference between the temperature of the housing and the ambient temperature;

  • the efficiency coefficient of the rib as a function of the coefficient of convective heat transfer.

The equation for calculating the dissipated heat is as follows:

where

  • — the heat transfer coefficient, set depending on the flow rate of the liquid (for forced convection) and the difference between the temperature of the housing and the ambient temperature;

  • — the total surface area of the heat exchange;

  • — the efficiency coefficient of the rib as a percentage, set depending on the coefficient of convective heat transfer. The efficiency coefficient of a rib is the ratio of the actual amount of heat dissipated by the rib to the amount of heat it would dissipate if its entire surface were at body temperature. This value depends on the geometry of the rib and its thermal conductivity.

Parameterization: rectangular parallel edges

If for the parameter Parameterization the value is set Assume rectangular parallel fins Then the block uses the following equations to calculate the dissipated heat:

where

  • ;

  • ;

  • ;

  • — Rayleigh number;

  • — the Reynolds number;

  • m/s 2 — acceleration of gravity;

  • — coefficient of thermal expansion of the liquid;

  • — kinematic viscosity of the liquid;

  • — thermal conductivity of the liquid;

  • — thermal conductivity of the liquid;

  • — rib height;

  • — rib length;

  • — edge width;

  • — the distance between the edges.

The total heat exchange area for edges in height and the cross section on , taking into account the fact that one side of the rib stands on the base of the radiator, it can be calculated using the formula:

The efficiency coefficient of a rectangular rib is determined by the formula:

where — thermal conductivity of the rib.

Variables

Use the parameter group Initial Targets to set the priority and initial target values for the block parameter variables before modeling. For more information, see Configuring physical blocks using target values.

Ports

Conserving

# A — Ambient temperature
heat

Details

A thermal port related to the ambient temperature.

Program usage name

ambient_port

# C — Case temperature
heat

Details

Thermal port related to the temperature of the case.

Program usage name

case_port

Input

# V — Flow rate
scalar

Details

An input signal that sets the value of the flow rate.

Dependencies

To use this port, set the parameter Convection value Forced - specify flow speed.

Data types

Float64
Complex numbers support

I don’t

Parameters

Steady State

# Parameterization — parameterization method
Datasheet | Tabulated convection and fin efficiency | Assume rectangular parallel fins

Details

The method of parameterization of the block, options to choose from:

Values

Datasheet | Tabulated convection and fin efficiency | Assume rectangular parallel fins
Default value

Assume rectangular parallel fins
Program usage name

fin_parameterization
Evaluatable

No

# Convection — type of convection
Natural | Forced - specify flow speed

Details

Choosing the type of simulated convection:

  • Natural — simulation of natural convection.

  • Forced - specify flow speed — simulation of forced convection, when selecting this parameter value, the v port appears in the block to set the flow rate.

Values

Natural | Forced - specify flow speed
Default value

Natural
Program usage name

convection_type
Evaluatable

No

# Vector of temperature rises above ambient, T — vector of values of the difference between the body temperature and the ambient temperature
K | degC | degF | degR | deltaK | deltadegC | deltadegF | deltadegR

Details

The vector of values of the difference between the body temperature and the ambient temperature. The values of this parameter must be positive and strictly increasing.

Dependencies

To use this parameter, set for the parameter Parameterization meaning Datasheet or Tabulated convection and fin efficiency.

Units

K | degC | degF | degR | deltaK | deltadegC | deltadegF | deltadegR
Default value

[10.0, 30.0, 50.0, 70.0, 90.0] K
Program usage names

T_datasheet_vector, T_tabulated_vector
Evaluatable

Yes

# Vector of fluid flow speed, v — vector of fluid flow velocity
m/s | mm/s | cm/s | km/s | m/hr | km/hr | in/s | ft/s | mi/s | ft/min | mi/hr | kn

Details

The vector of the fluid flow velocity. The values of this parameter must be positive and strictly increasing.

Dependencies

To use this parameter, set for the parameter Parameterization meaning Datasheet or Tabulated convection and fin efficiency, and for the parameter Convection meaning Forced - specify flow speed.

Units

m/s | mm/s | cm/s | km/s | m/hr | km/hr | in/s | ft/s | mi/s | ft/min | mi/hr | kn
Default value

[0.0, 1.0, 2.0, 3.0] m/s
Program usage names

v_datasheet_vector, v_tabulated_vector
Evaluatable

Yes

# Corresponding heat dissipated to ambient, Q_TLU1(T) — the heat discharged into the environment, corresponding to the difference between the temperature of the housing and the ambient temperature
W | uW | mW | kW | MW | GW | V*A | HP_DIN

Details

The vector of values of the heat discharged into the environment, corresponding to the values of the difference between the temperature of the housing and the ambient temperature. The values in this parameter correspond to the values of the temperature difference in the parameter Vector of temperature rises above ambient, T. The values of this parameter must be positive and strictly increasing.

Dependencies

To use this parameter, set for the parameter Parameterization meaning Datasheet, and for the parameter Convection meaning Natural.

Units

W | uW | mW | kW | MW | GW | V*A | HP_DIN
Default value

[6.1, 23.6, 44.5, 67.5, 92.3] W
Program usage name

Q_dissipated_vector
Evaluatable

Yes

# Corresponding heat dissipated to ambient, Q_TLU2(T, v) — the heat discharged into the environment, corresponding to the difference between the temperature of the housing and the ambient temperature and the flow rate
W | uW | mW | kW | MW | GW | V*A | HP_DIN

Details

A matrix of values of the heat discharged into the environment, corresponding to the values of the flow rate and the difference between the temperature of the housing and the ambient temperature. The values in this parameter correspond to the values of the temperature difference in the parameter Vector of temperature rises above ambient, T.

Dependencies

To use this parameter, set for the parameter Parameterization meaning Datasheet, and for the parameter Convection meaning Forced - specify flow speed.

Units

W | uW | mW | kW | MW | GW | V*A | HP_DIN
Default value

[6.1 18.8 22.8 25.7; 23.6 61.1 73.0 81.5; 44.5 106.4 125.9 140.1; 67.5 153.5 180.7 200.3; 92.3 202.1 236.9 262.0] W
Program usage name

Q_dissipated_matrix
Evaluatable

Yes

# Corresponding convective heat transfer coefficient, h_TLU1(T) — coefficients of convective heat transfer corresponding to the difference between the body temperature and the ambient temperature
W/(m^2*K) | Btu_IT/(hr*ft^2*deltadegR)

Details

The values of the coefficients of convective heat transfer corresponding to the values of the difference between the temperature of the housing and the ambient temperature.

Dependencies

To use this parameter, set for the parameter Parameterization meaning Tabulated convection and fin efficiency, and for the parameter Convection meaning Natural.

Units

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

[5.4, 7.02, 7.98, 8.68, 9.26] W/(m^2*K)
Program usage name

h_corresponding_vector
Evaluatable

Yes

# Corresponding convective heat transfer coefficient, h_TLU2(T, v) — the coefficients of convective heat transfer corresponding to the difference between the temperature of the housing and the ambient temperature and the flow rate
W/(m^2*K) | Btu_IT/(hr*ft^2*deltadegR)

Details

The values of the coefficients of convective heat transfer corresponding to the values of the body temperature and ambient temperature differences and flow rates.

Dependencies

To use this parameter, set for the parameter Parameterization meaning Tabulated convection and fin efficiency, and for the parameter Convection meaning Forced - specify flow speed.

Units

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

[5.4 17.86 22.17 25.41; 7.02 19.49 23.8 27.03; 7.97 20.44 24.75 27.99; 8.68 21.15 25.46 28.69; 9.26 21.73 26.04 29.27] W/(m^2*K)
Program usage name

h_corresponding_matrix
Evaluatable

Yes

# Vector of convective heat transfer coefficients, h — vector of convective heat transfer coefficients
W/(m^2*K) | Btu_IT/(hr*ft^2*deltadegR)

Details

Coefficients of convective heat transfer. This parameter depends on the temperature difference caused by natural convection and the fluid flow velocity caused by forced convection. The values of this parameter must be positive and strictly increasing.

Dependencies

To use this parameter, set for the parameter Parameterization meaning Tabulated convection and fin efficiency.

Units

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

[5.0, 10.0, 15.0, 20.0, 25.0, 30.0] W/(m^2*K)
Program usage name

h_vector
Evaluatable

Yes

# Corresponding fin efficiency (percent), eff_TLU(h) — rib efficiency coefficients corresponding to heat transfer coefficients

Details

The efficiency coefficients of the rib, in percentages, corresponding to the coefficients of convective heat transfer. The efficiency coefficient of a rib is the ratio of the actual amount of heat dissipated by the rib to the amount of heat it would dissipate if its entire surface were at body temperature. This value depends on the geometry of the rib and its thermal conductivity.

Dependencies

To use this parameter, set for the parameter Parameterization meaning Tabulated convection and fin efficiency.

Default value

[96.97, 94.16, 91.53, 89.08, 86.78, 84.62]
Program usage name

efficiency_vector
Evaluatable

Yes

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

Details

The total surface area of the heat exchange.

Dependencies

To use this parameter, set for the parameter Parameterization meaning Tabulated convection and fin efficiency.

Units

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

0.1171 m^2
Program usage name

total_heat_exchange_area
Evaluatable

Yes

# Fin height — edge height
m | um | mm | cm | km | in | ft | yd | mi | nmi

Details

Edge height.

Dependencies

To use this parameter, set for the parameter Parameterization meaning Assume rectangular parallel fins.

Units

m | um | mm | cm | km | in | ft | yd | mi | nmi
Default value

0.0381 m
Program usage name

fin_height
Evaluatable

Yes

# Fin thickness — edge width
m | um | mm | cm | km | in | ft | yd | mi | nmi

Details

The width of the edge.

Dependencies

To use this parameter, set for the parameter Parameterization meaning Assume rectangular parallel fins.

Units

m | um | mm | cm | km | in | ft | yd | mi | nmi
Default value

0.00065 m
Program usage name

fin_thickness
Evaluatable

Yes

# Fin depth — rib length
m | um | mm | cm | km | in | ft | yd | mi | nmi

Details

The length of the edge.

Dependencies

To use this parameter, set for the parameter Parameterization meaning Assume rectangular parallel fins.

Units

m | um | mm | cm | km | in | ft | yd | mi | nmi
Default value

0.1397 m
Program usage name

fin_depth
Evaluatable

Yes

# Gap between fins — the distance between the edges
m | um | mm | cm | km | in | ft | yd | mi | nmi

Details

The distance between the edges.

Dependencies

To use this parameter, set for the parameter Parameterization meaning Assume rectangular parallel fins, and for the parameter Convection meaning Forced - specify flow speed.

Units

m | um | mm | cm | km | in | ft | yd | mi | nmi
Default value

0.0094 m
Program usage name

fin_gap
Evaluatable

Yes

# Number of fins — number of edges

Details

The number of edges. The value of this parameter must be equal to or greater than 1.

Dependencies

To use this parameter, set for the parameter Parameterization meaning Assume rectangular parallel fins.

Default value

11
Program usage name

fin_count
Evaluatable

Yes

# Fin thermal conductivity — thermal conductivity of the rib
W/(m*K) | mW/(m*K) | Btu_IT/(hr*ft*deltadegR)

Details

Thermal conductivity of the fins.

Dependencies

To use this parameter, set for the parameter Parameterization meaning Assume rectangular parallel fins.

Units

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

237.0 W/(m*K)
Program usage name

k_fin
Evaluatable

Yes

Fluid Properties

# Fluid kinematic viscosity — kinematic viscosity of a liquid
m^2/s | mm^2/s | in^2/s | ft^2/s | St | cSt | newt

Details

Kinematic viscosity of a liquid.

Dependencies

To use this parameter, set for the parameter Parameterization meaning Assume rectangular parallel fins.

Units

m^2/s | mm^2/s | in^2/s | ft^2/s | St | cSt | newt
Default value

1.51e-05 m^2/s
Program usage name

nu
Evaluatable

Yes

# Fluid thermal diffusivity — thermal conductivity of the liquid
m^2/s | mm^2/s | in^2/s | ft^2/s | St | cSt | newt

Details

Thermal conductivity of the liquid.

Dependencies

To use this parameter, set for the parameter Parameterization meaning Assume rectangular parallel fins.

Units

m^2/s | mm^2/s | in^2/s | ft^2/s | St | cSt | newt
Default value

2.07e-05 m^2/s
Program usage name

a
Evaluatable

Yes

# Fluid thermal conductivity — thermal conductivity of the liquid
W/(m*K) | mW/(m*K) | Btu_IT/(hr*ft*deltadegR)

Details

Thermal conductivity of the liquid.

Dependencies

To use this parameter, set for the parameter Parameterization meaning Assume rectangular parallel fins.

Units

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

0.025 W/(m*K)
Program usage name

k_fluid
Evaluatable

Yes

# Fluid coefficient of volume thermal expansion — coefficient of thermal expansion of a liquid
1/K | 1/degR | 1/deltaK | 1/deltadegC | 1/deltadegF | 1/deltadegR

Details

Coefficient of thermal expansion of the liquid.

Dependencies

To use this parameter, set for the parameter Parameterization meaning Assume rectangular parallel fins.

Units

1/K | 1/degR | 1/deltaK | 1/deltadegC | 1/deltadegF | 1/deltadegR
Default value

0.0033 1/K
Program usage name

alpha
Evaluatable

Yes

Dynamics

# Heatsink mass — radiator weight
kg | mg | g | t | lbm | oz | slug

Details

Radiator weight.

Units

kg | mg | g | t | lbm | oz | slug
Default value

0.35 kg
Program usage name

mass
Evaluatable

Yes

# Heatsink specific heat — specific heat capacity of the radiator
J/(kg*K) | kJ/(kg*K) | cal/(kg*K) | kcal/(kg*K) | cal/(g*K) | kcal/(g*K) | Btu_IT/(lbm*deltadegR)

Details

Specific heat capacity of the radiator.

Units

J/(kg*K) | kJ/(kg*K) | cal/(kg*K) | kcal/(kg*K) | cal/(g*K) | kcal/(g*K) | Btu_IT/(lbm*deltadegR)
Default value

437.0 J/(kg*K)
Program usage name

c_p_heatsink
Evaluatable

Yes