Hi everyone,
I have a duct which opens to a LARGE VOLUME. To model the flow inside the DUCT, I am specifying an unsteady inlet velocity. At exit of the duct, pressure is not known and the pressure variation with respect to time should be a part of the solution. But I can specify a pressure value at time t=0 to begin with.
In the comsol modelling guide, I found out that specifying open boundary - no viscous stress condition doesn't impose any constraint on pressure. Thats what I need in this problem( that is pressure at exit of duct should not be constrained, since it should be a part of solution). But there will be boundary layer effect close to the duct walls. Hence my doubt is that how no viscous stress condition can be specified. Once again, the exit of duct is open to a large volume.
Can any one suggest whether this no viscous stress boundary condition is appropriate, if the boundary is open to a large volume?
Thanks in advance
SM Ananth
I have a duct which opens to a LARGE VOLUME. To model the flow inside the DUCT, I am specifying an unsteady inlet velocity. At exit of the duct, pressure is not known and the pressure variation with respect to time should be a part of the solution. But I can specify a pressure value at time t=0 to begin with.
In the comsol modelling guide, I found out that specifying open boundary - no viscous stress condition doesn't impose any constraint on pressure. Thats what I need in this problem( that is pressure at exit of duct should not be constrained, since it should be a part of solution). But there will be boundary layer effect close to the duct walls. Hence my doubt is that how no viscous stress condition can be specified. Once again, the exit of duct is open to a large volume.
Can any one suggest whether this no viscous stress boundary condition is appropriate, if the boundary is open to a large volume?
Thanks in advance
SM Ananth