viscous-pressure forces

nico

hi

i have some problems with the forces output from fluent i am testing a sailing boat rudder at different angle of attack at 0° i have viscous forces that look right but very big pressure forces what does pressure forces represents here?

finally i wondering what booundary conditions i should use i have seen many tutorial but none with low speed velocity inlet for inlet but what for outlet (outflow or pressure) and for the sides (wall symetry(only for 0° angle of attack) or velocity inlet too

thank u so much