Week-11 : Discretization of 3D intake manifold using GEM-3D
1. Tutorial- single cyl DI add case 2 with discretization length 0.1 mm for intake runner and compare with default case 1
- Parameters-Torque, BSFC, max cylinder pressure
- simulation time
The above model is a simple single cylinder diesel engine.
As required, the object value of discretization length was set up for the same speeds.
As it can be seen in the above image, case setup was created with baseline discretization length of 40mm and the new length of 0.1 mm.
Results:
The simulation time for the two cases can be seen in the image below. It is clear that, for the case with 0.1 discretization, simulation time is higher. It will effect the accuracy of the results as well.
The break torque is as follows,
DL 40mm --> 96.2 N-m
DL 0.1mm --> 95.9 N-m
BSFC
DL 40mm --> 4950 g/kW-h
DL 0.1mm --> 4882 g/kW-h
Even though the results are not much different, there is more accuracy with the DL of 0.1mm.
Similarly,
Maximum cylinder pressure
DL 40mm --> 117.11 bar
DL 0.1mm --> 115.18 bar
Depending on our requirement, we can chose either accuracy or simulation time.
Explore tutorial no 2 (GEM3D) - “Building intake manifold from STL model”
Initially, import a CAD model using GEM 3D option. Here we can see intake manifold with 4 runners.
As shown according to the below images, We will have to separate the model into sections using a cutting plane. Initially we have to remove caps and then seperate intake runners inorder to make them in to round pipes. Later, the manifold needs to be converted as a flowsplit. Once, it is done, the separated sections need to be connected to align. After aligning all the connections, the flow direction needs to be finalized. Now that the entire conversion is completed, the model can be exported to GT model.
