Hello Anju,

Generally, in COMSOL you'll used the physic's model called Piezoelectric device (if we talk about piezoelectric energy harvesting system). In fact, we are connect this model through the physical COMSOL interface to the Circuit model (COMSOL). As results, we find the eigenfrequency, voltage generated during mechanical vibration, mechanical and electrical power depends on external frequencies (in structural mechanic as load). If you need to simulate piezoelectric or other system into the flow, you can integrated all models with additional fluid-structure interaction COMSOL's physic. It's depends on your wishes.

Regards

Finite Element Method Simulations: In the finite element method (FEM) simulations, we used the “electrostatics” module of COMSOL to calculate the electric potential distribution through the “stationary” study. First, we constructed the model of TENG used for simulation in this work. The geometry parameters of the parts of the model are as follows: the length and width of both friction materials are 55 and 55 mm, respectively; the thickness of aluminum foil and PTFE sheet, respectively, are 0.4 and 3 mm. The gap between aluminum foil and PTFE is 10 mm. Second, in the “material” section, we selected the aluminum and PTFE materials. The relative permittivity of PTFE was set to be 2.0. Third, the boundary conditions such as the surface charge density was being set and the mesh was built on the model by subdivision triangular grid. Finally, we could implement the computation to obtain the electric potential information”