Hi,<\/p>\n
A tiny bit of context: I’m running an open channel 2D Fluent simulation to try to find an outlet velocity profile to use as an inlet in a different case.<\/p>\n
My inlet for the first case is a mass flow inlet of water, with a surface height 1m in a 2m channel with a small slope (0.0005). I want it to run such that there are no surface waves (Fr<1). I have this figured out and choose to run a mass flow inlet of 2100kg\/s and get a flat, wave-free channel with a mass flow at outlet of almost, 2100kg\/s. Happy days. So i export the velocity profile.<\/p>\n
I then want to reuse this velocity profile in the same geometry with a pressure inlet specified by free surface height and velocity magnitude. When i put this v-prof into the v-mag box the mass flow i got is only around 1700kg\/s and seems to change as the solution converges.<\/p>\n
i need this mass flow rate to remain constant to control the simulation and avoid surface waves.<\/p>\n
a) Why is the mass flow not constant if i have a profile for velocity and a set height that doesnt change between the two cases? Have i not set both the U and the A (=h) of the inlet (Q=UA)?<\/p>\n
b) Why does this change during convergence?<\/p>\n
<\/p>\n
I’d hugely appreciate any help or suggestions for alternate ways i can do this<\/p>\n
<\/p>\n
-Nate<\/p>\n","protected":false},"template":"","class_list":["post-251461","topic","type-topic","status-closed","hentry","topic-tag-2-d","topic-tag-boundary-condition","topic-tag-fluent","topic-tag-fluid","topic-tag-gravity-1","topic-tag-mass-flow-inlet-boundary-condition-1","topic-tag-mass-flow-rate-1","topic-tag-massconservationcheck","topic-tag-open-channel-flow-1","topic-tag-pressure-inlet-boundary","topic-tag-pressure-velocity-1","topic-tag-profile","topic-tag-simulation","topic-tag-student"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t