thermalnetwork

Thermal network is a modeling approach that represents heat transfer in a system as a network of nodes connected by thermal elements. Each node has a temperature and each element represents a pathway for heat flow, typically treated as a thermal resistance, while energy storage is represented by thermal capacitances. The network is analogous to an electrical circuit, with heat flow playing the role of current and temperature difference driving the flow.

Nodes may represent individual components or spatial regions; branches denote conduction through solids, convection across interfaces, and, in some cases, radiative exchange; capacitances model the ability of regions to store heat. For many engineering problems, a lumped-parameter or RC network provides a simple, tractable approximation of the true heat transfer, which may be nonlinear or temperature dependent.

Modeling process: define the system boundary and discrete regions, assign thermal resistances and capacitances, and possibly nonlinear functions; write energy balances at each node; for small-signal or linear cases, solve a set of linear differential equations, often in matrix form: C dT/dt = -G T + ...; steady-state corresponds to solving G T = q.

Applications: electronics cooling, building energy modeling, automotive and aerospace thermal management, energy system optimization; advantages: fast, transparent, and easy to couple with control design; limitations: reduces spatial detail, may require linearization, and radiative heat transfer can complicate the model; accuracy depends on parameter calibration.

Related concepts include thermal impedance, lumped-capacitance method, and RC networks; tools: SPICE-like modeling, MATLAB/Simulink, Modelica.