I used five physics in COMSOL, including "Solid Mechanics", "Electrostatics", "Pressure Acoustics, Frequency Domain", "Laminar Flow", and "Particle Tracing for Fluid Flow" to simulate the effect of surface acoustic waves on the particles. Also, I used three studies, including "Stationary", "Frequency Domain", and "Time Dependent". For simulating "Solid Mechanics", "Electrostatics", and "Pressure Acoustics, Frequency Domain" physics, I used the Frequency Domain study. For simulating fluid flow in the channel, I used Laminar Flow study, and Particle Tracing was utilized for the detection particles movement. In the end, I faced an error as follow:
(
Complex number encountered in real expression.
- Expression: (comp1.fpt.Ftx-d(comp1.qx,t)*d(comp1.fpt.mp,t))/comp1.fpt.mp
- Geometry: Particles
)
Can anyone explain this problem?