# How the MeasureTool computes pressure for mDBC

Hi everyone,

Looking at the shell script in DualSPHysics_v5.0/examples/mdbc/04_Dambreak, '-onlytype' is set to '+all,+fluid' at line 74 to compute pressure acting on an obstacle by means of the MeasureTool code. I was thinking that numerical pressure is computed by the pressure values of neighbouring fluid particles, so I tried comparing the outputs between '+all,+fluid' and '-all,+fluid'.

The result of '+all,+fluid' looks realistic, while '-all,+fluid' leads to zero pressure. This indicates that the algorithm inside the MeasureTool for mDBC may be slightly different from the DBC, because the mDBC uses interpolation points just inside the fluid domain to reflect back into the solid domain. I would appreciate it if somebody could make it clear how the MeasureTool computes pressure for mDBC.

Thanks in advance.

## Comments

Please can you share your XML and Script (using MeasureTool) with us (dualsphysics@gmail.com)?

Otherwise we can not help you since we do not know what exactly are you using

In any case there is no difference for MeasureTool using DBC or mDBC, but what needs to be considered is the pressure gauge since now using mDBC there is no gap between boundary and fluid

Regards