Week 9: Project 1 - Surface preparation and Boundary Flagging (PFI)
Aim:
To setup a No Hydro case for IC engine in converge studio.
Objective:
The Tasks that you need to perform are
1, Boundary Flagging.
2, Surface preparartion.
After setting up the NO HYDRO case set up, make sure you create an animation for NO HYDRO and send it to us on freshdesk ([email protected])
Make sure you are submitting a detailed report explaining the entire setup of NO HYDRO and showing all errors you came across and explain the meaning of each error.
Also, show mesh on dfferent slices at different time steps.
In an animation, all the valves and piston should move according to the crank angles and if it looks fine to us we will ask for the FULL HYDRO case set up.
We will run this FULL HYDRO case in our cluster and provide you with 3D OUTPUT FILES and Averaged output files so that you make use of them to post process the results and get required plots respectively.
Procedure:
Geometry:
The PFI pure mathematics .stl file is foreign within the Converge Studio. the bottom pure mathematics has surface errors that require to be cleared before we have a tendency to move up with the simulation. Boundaries ought to be flagged for making the flow through the pure mathematics and taken regions square measure extracted to initialize the flow and to make the events between the regions.
From the diagnosis, it can be observed that the following errors are detected with the surfaces viz., intersections, Nonmanifolds, open edges & overlapping, etc.,.
Boundary Flagging:
To flag the boundaries, we'd like to make the fences across the sides of separating boundaries therefore it eases within the choice of boundaries.
Liner:
Two edges were chosen to mark the fence across the Liner edges and therefore the boundary is flagged mistreatment the boundary fence methodology as shown below.
Piston:
The piston is flagged by the boundary fence method as shown below.
Cylinder Head:
Boundary fences ar created on the four edges that separate the region of the ports & electrical device from the plate region and also the plate is extracted as shown below.
Intake Port / Inflow:
The intake port is split into 2 boundaries & later into 2 regions to separate the boundaries for various initial and boundary conditions. The intake port is wherever fuel spray and also the air is injected. A fence is formed employing a fence between vertices and acceptable boundaries ar flagged from the boundary fence technique.
Exhaust Port / Outflow:
The outflow is flagged using the boundary fence method and the rest of the region as outflow as shown below.
Valves:
Intake & Exhaust ports, Liner, and plate area unit hidden and so valves area unit visible. The valve pure mathematics is flagged into three boundaries. this is often done to make the events and ease within the creation of disconnect triangles and to assign realistic boundary conditions. Also, a translatory motion is provided to those valves by loading the motion files.
Spark Plug & Terminal:
The region where the spark is generated is at a higher temperature than the rest of the spark plug. Hence, two boundaries are necessary to assign appropriate conditions.
Top of Valve high appointed to port boundaries:
Due to the translatory motion of the valves and because it is connected to ports, throughout movement of the surface of the ports gets distorted. To avoid this distortion, the highest of the highest valves is appointed to the port boundary as shown below.
Flagged boundaries:
All the flagged boundaries are as shown below.
Surface Preparation:
From the diagnosis, it can be observed that the following errors are detected with the surfaces viz., intersections, Nonmanifolds, open edges & overlapping, etc.,.
As can be seen from the picture above, there exist intersections between the intake ports and cylinder head this is due to the clash of the geometry of intake valves and cylinder head. To avoid this error, valves are translated by little amount.
Once the intersections square measure cleared, nonmanifold triangles square measure deleted and open edges square measure cleared by mend and sewing the adjacent triangles. Then applicable traditional orientations square measure reworked relying upon the fluid flow domain. The on top of actions create the pure mathematics free from errors.
Regions:
Regions square measure produced that square measure accustomed create events between the zones and to initialize the realistic initial conditions within the flow domain.
Initial and Boundary Conditions:
| Case Parameters | Setup |
| Application Type | Crank angle-based IC engine |
| Physical Parameters |
Cylinder Bore: 0.086m Stroke: 0.09m Connecting rod length: 0.18m Crank speed: 3000rpm |
| Gas Simulation | Therm.dat uploaded |
| Reaction Mechanism | Mech.dat uploaded |
| Run Parameters |
Solver - Transient Type - Crank angle-based engine simulation Simulation mode - No Hydro |
| Simulation Time Parameters |
Start time: -480 deg End time: 240 deg |
| Solver Parameters |
Solver Scheme: PISO Type: Density-based |
Boundary Conditions:
| Piston |
Boundary Type - Wall Wall motion - Translating Surface Movement - Moving Law of Wall (Piston Motion) Temperature - 450K (Law of Wall) |
| Liner |
Boundary Type - Wall Wall motion - Stationary Surface Movement - Fixed Law of Wall Temperature - 450K (Law of Wall) |
| Cylinder Head | Boundary Type - Wall
Wall motion - Stationary Surface Movement - Fixed Law of Wall Temperature - 450K (Law of Wall) |
| Exhaust Port |
Boundary Type - Wall Wall motion - Stationary Surface Movement - Fixed Law of Wall Temperature - 500K (Law of Wall) |
| Intake Port1 |
Boundary Type - Wall Wall motion - Stationary Surface Movement - Fixed Law of Wall Temperature - 425K |
| Intake Port2 |
Boundary Type - Wall Wall motion - Stationary Surface Movement - Fixed Law of Wall Temperature - 425K |
| Spark Plug |
Boundary Type - Wall Wall motion - Stationary Surface Movement - Fixed Law of Wall Temperature - 550K |
| Spark Plug Terminal |
Boundary Type - Wall Wall motion - Stationary Surface Movement - Fixed Law of Wall Temperature - 600K |
| Intake Valve |
Boundary Type - Wall Wall motion - Translating Surface Movement - Moving Law of Wall Temperature - 480K Profile - loaded Minimum Lift - 2e-4m |
| Exhaust Valve |
Boundary Type - Wall Wall motion - Translating Surface Movement - Moving Law of Wall Temperature - 525K Profile - loaded Minimum Lift - 2e-4m |
| Inflow |
Boundary Type - Inflow Temperature- 363K Pressure - 101325 Pa Species - Air |
| Outflow |
Boundary Type - Outflow Temperature- 800K Pressure - 101325 Pa Species - CO2 - 0.192304 H20 - 0.088559 N2 - 0.719137 |
Regions:
| Cylinder Region |
Temperature - 1360K Pressure - 185731 Pa Species - CO2 - 0.192304 H20 - 0.088559 N2 - 0.719137 |
| Intake Port 1 |
Temperature - 390K Pressure - 101325Pa Species IC8H18 - 0.025508 O2 - 0.20157 N2 - 0.77292 |
| Intake Port 2 |
Temperature - 370K Pressure - 101325Pa Species - Air |
| Exhaust Region |
Temperature - 1360K Pressure - 185731 Pa Species - CO2 - 0.192304 H20 - 0.088559 N2 - 0.719137 |
Events:
| Cyclic |
Between Cylinder region & Intake Port 1, Period -720 deg, Event - Valve Between Cylinder region & Exhaust Region, Period -720 deg, Event - Valve |
| Permanent | Between Intake Port 1 & Intake Port 2, Event -Open |
Mesh Size:
Here the bottom grid of zero.004m is employed beside the mounted embedding. For the Intake and valve angle scale of three and one embedding layer is employed with Permanent Mode. Whereas, for the Cylinder region and zones next to the valves within the ports a cylinder entity is employed with a scale of two & one, severally.
The results ar processed for No-Hydro simulation and therefore the grid size is inferior by an element of four (n = -2) because the computation time was too high for the fine mesh. Grid was inferior because it was solely a no-hydro simulation. The simulation took 263 sec whereas running it with six processors.
The movement of the complete setup is as shown below:
Conclusion:
Hence we have Obtained the No Hydro Ic engine full simulation with Graphs and animations.