Use the Heat Source feature to add a domain heat source that generates sound. If a fluid is heated and cooled rapidly, thermal expansion and contraction will generate acoustic waves. This could be a source representing a pulsating laser beam or a flame source in a combustion simulation. The feature adds a monopole domain source to the right-hand side defined as

where the (isobaric) coefficient of thermal expansion αp is defined in terms of the speed of sound c, heat capacity at constant pressure Cp, ambient temperature T (this value is taken from the model inputs and can be space dependent), and ratio of specific heats γ.

Specify the Heat source strength Qheat (SI unit: W/m3).

Enter the additional fluid properties necessary to define the heat source. Enter the Heat capacity at constant pressure Cp (SI unit: J/(kg·K)) and the Ratio of specific heats γ (dimensionless). The default for both is From material. Select User defined to enter a value or expression directly.