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How to find time integration of a variable changing at every time step?
Posted Dec 28, 2021, 9:07 a.m. EST General, Parameters, Variables, & Functions, Equation-Based Modeling Version 5.5 2 Replies
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Hello,
I am using Comsol 5.5 multiphysics for simulating the movement of an object in a fluid and a viscous force is acting on the object due to the movement of fluid. What I need to find is the displacement of the object due to the viscous force. The resulted displacement at every timestep will be given to the mesh to see the movement of the mesh.
I need to implement the following equations in comsol.
V(n) = V(n-1) + a(n) x dt(timestep)
S(n) = S(n-1) + V(n) x dt(timestep)
Where V(n) and V(n-1) are the velocities of the object at timestep n and n-1 respectively. Please note that the force acting and the displacement of the object are coupled to each other as force will change due to the change in location of boundaries of the object.
Thanks,
Akshay Kargaonkar
Indian Institute of Technology, Dhanbad
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About half way down on this page you will see that version 6 has a new cumulative integration option... is this what you are after?
https://www.comsol.com/release/6.0/postprocessing-and-visualization
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Hello Akshay, For integrating in time, see also the "Time Integrals" section of: https://www.comsol.com/support/knowledgebase/913