Hi, I’m doing an transient analysis for an Intake manifold, I’m studying air performance in the intake for the cylinder heads in the fire order of 1 - 4 - 2 - 3 and few analysis before I did a transient analysis called (Transient 3) it’s not the best analysis but at least I already seen the velocity profile for each cylinder, because my type of account that is the student license I have the restriction of maximum runtime so I was trying with the fire order of 3-1-4 to analyse the performance of cylinder 1, and later try with the fire order of 1-4-2 to analyse the performance of cylinder 2 and the same for cylinder 3 and 4, I change the pressure pulse and time step for the new analysis called (Transient 314 test), but didn’t pass for the first pressure pulse… the mass flow, and pressure pulse is different but i don’t know why don’t behave as (Transient 3). I was trying to change some relaxation factor, and gradient schemes but it didn’t work. Also, I was trying to refine the mesh, because I have some Non Orthogonality >75 degrees but they didn’t disappear.
NOTE: You can find the analysis in the Compressible 8 section.
To begin with, regardless of the graphs you provided, it seems you are using different boundary conditions between the two case. Specifically, in ‘Transient 3’ you are using a Pressure inlet for face 236, and in ‘Transient 314 test’ you are switching to a Velocity inlet. Why did you choose to change this boundary condition?
Regarding the graphs, you can see that ‘Transient 314 test’ stopped after 2.6e-3 sec. That’s before the first pulse.
Hi Fillia, I used pressure inlet because I thought will be better for the convergence, and I used in the another simulation velocity inlet as flow rate because it’s a parameter for the intake. My doubt is why in ‘Transient 314 test’ made more calculations than ‘Transient 3’, because I just changed the pressure pulse data and the time steps, because the last ones are corrected. Actually, I changed the mesh and refined some faces that were with non orthogonality >80, but I made som runs ‘transient 314 test 2 to transient 314 test 7’ with diferent setup , because the face 242 I don’t want to analize this outlet, I usually put that face with a wall condition, but also I tried with the face 242 with a fixed pressure outlet condition but it didn’t work. So I don’t know what’s happening all runs diverged
I will appreciate it.
