This tutorial illustrates a transient two-way fluid-thermal simulation of the convection heating of the fluid in a tank. The model consists of a fluid-filled cylindrical tank with a heating source, a temperature sensor, and a thermostat.

Figure 57: Convection heating of the fluid in a tank

The tank is heated from the bottom by a heat source, which is regulated by a thermostat connected to a temperature sensor near the top of the tank.

The Fluent participant models the fluid in the tank. A thermal convection boundary condition — with a temperature of 295K assumed for the surroundings is applied to the top of the tank, while gravity and thermal buoyancy in the fluid model are set to ensure natural convection.

A Functional Mock-up Unit (FMU) participant models the thermostat and heating control system. The thermostat receives a Temperature (in K) from the Fluent sensor and outputs a Heat Rate (in W). The FMU has three parameters that you can set: Target Temperature (in K), Maximum Heat Output (in W), and Heat Scale Factor (in W/K).