Thermal

The Thermal menu allows the user to define the thermal properties of the system and to add Temperature Controllers to regulate temperature.

Temperature Controllers

Temperature Controllers are Heaters and Coolers that can be configured for your spacecraft. These devices are Components that are assigned to regulate the temperature of their assigned Component. Target temperatures are managed by Control States linked to Routines. During an active state Temperature Controllers will be active only when the temperature goal is not met. For Coolers this means the regulated interface will receive full cooling until the temperature is at or below commanded. For Heaters this means the regulated interface will receive full heating until the temperature is at or above the commanded.

Controllers have a single controlled Component but do not need to be connected directly to that Component. Indirect control by heating/cooling nearby structures according to the controlled Component state is supported.

To create a Temperature Controller, specify the power source (** this means that no Load State is required for this component for temperature regulation **) regulation rate, efficiency, and thermal properties. Also specify the component which is to be regulated by this Temperature Controller.

After clicking "Save", you will be given the option to create a Control State. A Control State specifies the fixed temperature to maintain and during which Operational Modes this should occur. Note that this allows for different fixed temperatures during different Operational Modes.

Thermal Interfaces

Thermal Interfaces are what allows heat to flow between components during the simulation. Lack of an interface connection to a Component indicates to the simulation that a Component is completely isolated. Thermal radiation is not currently modeled between Components.

To create an interface, click on a Component and drag the line to the Component you with to connect it to. Components not currently connected are stored to the upper right of the Thermal Interface chart. Drag with the mouse to reveal more canvas.

Surfaces are unique. They are non-physical entities representing aspects of other components. Each Surface must be attached to one (and only one) component. The interface between the surface and the component will always have zero thermal resistance to represent the fact that the surface is part of that component.

For Thermal Interfaces used between Temperature Controllers and a sink Component and a regulated Component, remember: The regulated Component does not need to be the same as the Temperature Controller`s controlled Component.

Upon connecting two nodes in the diagram, you will be prompted to select a Thermal Interface Material, a cross-sectional area, and a thickness for the interface. A larger contact area or smaller thickness means less thermal resistance.

Thermal Interface Material

Thermal Interface Materials are used to describe the heat flow resistance between connected items on the spacecraft. You can think of a Thermal Interface Material like a sheet of padding and a Thermal Interface as a patch that has been cut out of the pad. Like Solar Cells, these can be re-used for multiple Thermal Interfaces.

To create a Thermal Interface Material, click the "+" button at the bottom of the table. Specify the thermal resistivity in K·m/W, an intensive property of the material.