[Lietuvis]

Hello. I'm trying to get resistance of the ships hull using FLOW-3D. Now i'm using viscosity and turbulence physics modeler>Laminar (under turbulence options). As output results i'm getting pressure forces and shear forces. Shear forces are very very small. So does shear forces=friction resistance and pressure forces=viscous/wave making resistance? Do i have to enable some of the turbulence physics models to get correct friction resistance results? Do i have to set hull's roughness or/and material properties? So far i'm not very good at understanding it, so step by step explanation would be great.

[M.Nazrin]

to get the output shear force and pressure that exert by the ship hull, u need to tick the pressure and shear output button. the button can be located at;

model setup>meshing & geometry>geometry>component properties>output.

the visualization data can be only visualized using Flow Sight.

hope this help u.

[anazemian]

Hi
for resistance calculation, you need firstly import STL format geometry and adjust geometry information in Flow-3D software, in ship resistance we have trim and sinkage motion that is related to pitch and heave motion. the software gives you pressure and shear resistance that means pressure and friction resistance. wave making resistance and viscous pressure resistance are in pressure resistance and shear resistance just give you frictional resistance both of Cf and kCf(friction and curvature resistance) (1+k)Cf
Although flow-3d cannot calculate the shear resistance precisely because of orthogonal grids. other software has curvature-base mesh and could capture boundary layer flow that relates to frictional resistance.
you can use multiblock mesh and conform some blocks to make smaller mesh size. it forced you to find high-speed computer for calculation. but Flow-3D is a good software for seakeeping(ship dynamics in waves) calculation. if you have a problem which has both resistance and seakeeping its better choose flow-3D but if you just have resistance problem and accuracy is very important choose another software like fluent