Lemonergy · Studio block

Coolant pressure and temperature boundary

Fixes pressure and inflowing coolant temperature at one liquid terminal. In the plate example, inlet and outlet are two instances of this same boundary.

Implementation ID: liquid-reservoir
Reviewed: 2026-10-27

Behavior

This ideal boundary supplies or receives coolant while holding its configured pressure and inflow temperature. A pressure difference across the cooling plate determines the flow. When flow reverses, the receiving boundary becomes the supplying boundary. Outgoing coolant carries the plate outlet temperature; the receiving boundary does not clamp that outlet temperature.

Interface

What inlet and outlet actually mean

Both are coolant boundary blocks. Their names describe the example role; their pressures determine the actual direction.

Scroll the diagram sideways to see every connection.

The same boundary type can supply or receive coolant. Its temperature is the inflow condition; it does not clamp the exiting coolant temperature.

Select a pin or output for its meaning. Lines identify the interface; they are not a completed simulation circuit.

Ports and observed outputs
Name	Direction	Unit	Meaning
`a`	terminal	Pa / kg/s / K / W	Thermal-liquid terminal connecting this boundary to a cooling plate. The boundary fixes pressure and the temperature used when coolant flows out of the boundary. Mass and enthalpy reaction flows balance the connected plate.
`pressure`	output	Pa	The configured absolute pressure at this boundary.
`temperature`	output	K	The configured inflow temperature, not a measurement of returning coolant.
`massFlow`	output	kg/s	Net mass flow into this boundary. Negative when it supplies the plate; positive when it receives returning coolant.
`enthalpyFlow`	output	W	Net advected enthalpy flow into this boundary. Returning coolant uses its plate outlet temperature.

Parameters

Defaults are initial model values. Select values for your own model and operating conditions.

Configuration fields
Parameter	Unit	Default	Meaning and limits
Boundary pressure `pressurePa`	Pa	101325	Absolute pressure held at this liquid node. Set a pressure difference between the two boundaries to drive coolant flow. Minimum 1; Maximum 1000000000.0
Coolant supply temperature `temperatureK`	K	300	Temperature of coolant supplied by this boundary. It is used as the inlet condition only when flow leaves this boundary. Minimum 0; Maximum 5000

Equations and rules

pressure = pressurePa
inflow temperature = temperatureK
boundary massFlow + mass flow leaving the boundary = 0

Worked example

Two boundaries in the U-channel plate example

The existing U-channel example sets inlet to 200000 Pa and outlet to 100000 Pa, both at 300 K. The plate carries 0.1 kg/s from inlet to outlet. These checks describe the boundary within the released plate network, not a separate standalone validation.

Open Studio example →

Numerical checks for the bundled synthetic example
Output	Expected value	Unit	Absolute tolerance
Supply boundary pressure `inlet/pressure`	`200000`	Pa	1e-06
Supply coolant temperature `inlet/temperature`	`300`	K	1e-06
Mass supplied by inlet boundary `inlet/massFlow`	`-0.1`	kg/s	1e-09

Use in a workflow

Edge-cooled plate worked example

A plate with four thermal contacts and a defined coolant path. Explore which body connects to each contact and how pressure drives coolant through the plate.

Coolant inlet boundary: Sets 200 kPa and 300 K at plate a; supplies coolant for the positive pressure difference.
Coolant outlet boundary: Sets 100 kPa at plate b; receives coolant. Its 300 K supply temperature is used if flow reverses.

Open Studio example

Parallel-channel plate worked example

A plate with four thermal contacts and a defined coolant path. Explore which body connects to each contact and how pressure drives coolant through the plate.

Coolant inlet boundary: Sets 200 kPa and 300 K at plate a; supplies coolant for the positive pressure difference.
Coolant outlet boundary: Sets 100 kPa at plate b; receives coolant. Its 300 K supply temperature is used if flow reverses.

Open Studio example

U-channel plate worked example

A plate with four thermal contacts and a defined coolant path. Explore which body connects to each contact and how pressure drives coolant through the plate.

Coolant inlet boundary: Sets 200 kPa and 300 K at plate a; supplies coolant for the positive pressure difference.
Coolant outlet boundary: Sets 100 kPa at plate b; receives coolant. Its 300 K supply temperature is used if flow reverses.

Open Studio example

Connected concepts

Limits and interpretation

Ideal fixed pressure and inflow temperature, not a finite tank, pump or radiator model. Each coolant node requires exactly one explicit boundary in the current bounded plate solver.
Boundary checks reuse the existing released U-channel network; they are synthetic model checks, not measured equipment data.

Scientific and mathematical references

These sources explain the scientific and mathematical background. The behavior, interface and limits above define the Lemonergy implementation; a citation does not imply every model option in the source is implemented.

University Physics Volume 2, §1.6: Mechanisms of Heat Transfer
OpenStax, Rice University
Technical reference · Conduction, convection, radiation and thermal resistance.

Implementation sources

This reference follows the public interface and numerical checks for the verified Studio release. Synthetic examples and model limits remain as documented above.

Contract: Lemonergy Studio public contract · Verification record: verification-2026-10-27

Production revision: e76cadfc203e15eb41f3478d8b1044a5b851953d · Verified: 2026-10-28

docs/glossary/native-block-verification.json

This implementation and its workflow uses (JSON) · Knowledge graph (JSON-LD)