Bottom Shear Stress

Question

Hello Chris,

How the bottom shear stress calculated in ELCOM or AEM3D? Should CAEDYM model activated to calculate that? Does keyword "SHEAR" in Sheet output with <type> bottom (in datablock file) gives us the bottom shear stress. If not which probably not because I got very odd values once I tried, how can that parameter be calculated. could you please share with me calculation method.

sorry for lots of questions but I really confused. U_BOTTOM_STRESS and V_BOTTOM_STRESS both give me zero values for entire domain and simulation time. I tried it in Round_Lake Example.

Thanks,

Mohammad

Answer 1

U_BOTTOM_STRESS and V_BOTTOM_STRESS are the stresses (actual output is stress/density) from water velocity. I get values for these in the Round Lake example

RESUSP_STRESS is the stress calculated for the sediment resuspension and included velocity stress and an estimate of wave generated stress.

Comments

Thanks, May I ask when you run the round Lake the Caedym was activated or not. Do you still get values without Caedym and WQ module activated. Because I got zeros and I expect stresses should be calculated just with hydrodynamic modeling.

Thanks

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Also I still don't know what the "SHEAR" output means in SHEET data.

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The bottom stress is only calculated if it is required for resuspension or if the bottom drag bc type is being used.

SHEAR is the vertical velocity shear used in the mixing model