Usually Reynolds number is calculated initially (like flow over an sphere) using the geometry and domain velocity. If you want to compute Reynolds number during simulation anyways you should be able to do so by measuring the velocity at a specific point / surface / volume and then calculate it your self in post-processing. I do not know of any way to output Reynolds number in DualSPHysics, but maybe I am mistaken and would like to be corrected if I am.
If I misunderstood what you really wanted, try rephrasing your question.
Comments
Usually Reynolds number is calculated initially (like flow over an sphere) using the geometry and domain velocity. If you want to compute Reynolds number during simulation anyways you should be able to do so by measuring the velocity at a specific point / surface / volume and then calculate it your self in post-processing. I do not know of any way to output Reynolds number in DualSPHysics, but maybe I am mistaken and would like to be corrected if I am.
If I misunderstood what you really wanted, try rephrasing your question.
Kind regards