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step function issue

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Hello all,

I have a dynamic system that I simulate for 0.2 seconds. It has two angular velocities of interest, the flapping and the rotation rates. I run 4 simulations in total. They all have the same flapping and rotation rate profile with one difference: I add or subtract some number (epsilon) at t=0.01 s. I use the step function for this process and define a transition region to avoid convergence issues.

The problem is the strain difference between two cases appears at t=0.08, although the perturbation is applied at t=0.1. Interestingly, it is not the case when we perturbed the rotation rate, that is, there is an inconsistency.

Any ideas? Thanks in advance!

Summary of Simulations

  • sim1: nominal trajectory+step function on flapping

  • sim2: nominal trajectory-step function on flapping

  • sim3: nominal trajectory+step function on rotation

  • sim4: nominal trajectory-step function on rotation simulation time step=0.001 s

Step Function Parameters

Location: 0.1 sec

From: 0 To: 0.01

Size of Transition: 0.001 s



0 Replies Last Post 2021年3月5日 GMT-5 18:47
COMSOL Moderator

Hello Burak Boyacioglu

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