Assignment 11

Aim

To perform simulation on single cyl DI with varying the discretization length 0.1 mm for intake runner and compare with default case 1.

And explore tutorial on building intake manifold from STL model.

Outline

It is single cylinder direct injection diesel engine with single intake runner and exhaust runner.

Case setup

Above is the case setup for the simulation where the changes are made in the discretization length of the intake runner. There are two cases , Case1 is the default setup with 40 mm discretization length and case 2 of 0.1 mm discretization length.

Result

Here we can see the Performance of this engine

Case 1

Torque = 96.19649 N-m 

BSFC = 238.2448 g/kWh

Max Cylinder Pressure =  117.1117 bar

Case 2

Torque = 95.92096 N-m

BSFC = 238.92914 g/kWh

Max Cylinder Pressure = 115.1759 bar

Above is the simulation time for each case that has been simulated.

Intake Manifold Bulid

Initial

This is the initial model of the intake manifold which is going to be changed. 

Step 2 

Is cutting the plane using the three point cutting curve in the convert tab

Next is converting the runners from the main splitters.

Runner 1

Select one runner in the main flow and right click to Convert to Shape Component 

Select the type of flow to PIPE 

Next is to select  Bend Type - Multiple Bends . Next is define diameter by User Defined Diameter = 48.6 mm in part 1 and selecting define from part 1 in part 2  

Here we are checking the Wall Thickness to 1 mm

Finally we are defining the Initial State Name and defining the Pressure = 1 bar, Temperature  = 300 K and Composition = Air.

Similiarly it is done for the next three runners.

This is end result of the conversion of the runner.

Runner 2 

Select one runner  and right click to Convert to Shape Component 

 Select the type of flow to PIPE.  

Next is to select  Bend Type - Multiple Bends . Next is define diameter by User Defined Diameter = 48.6 mm in part 1 and selecting User Defined Diameter = 38.3 mm in part 2. 

Here we are checking the Wall Thickness to 1 mm.

Finally we are defining the Initial State Name and defining the Pressure = 1 bar, Temperature  = 300 K and Composition = Air.

Similiarly it is done for the next three runners.

   

This is end result of the conversion of the runner.

Ports Connection

Now making the Ports for the runners

Port - 1

  

Select the runner. Right Click to Add Connections.

Select Port 1 and connection as OrificeConn.

Set Forward Discharge Coefficient as discharge Coeff and set to 0.95.

Do it similarly to the next runners. 

Port 2

Select the runner. Right Click to Add Connections.

Select Port 2 and connection as GEMsubAsstExtConn.

Select the flow direction as Outlet and assign port ID as 1. 

This is end result of the conversion which can be seen on the leftside on the tree.

Intake Pipe Section 1

The Intake Pipe Section 1 is first cut using the Pipe Normal Cutting plane in the convert tab.

Right click to Convert Shape to Component.

Select flow Volume to PIPE.

Next is to select  Bend Type - Straight . Next is define diameter by Measured Effective Diameter = 53.816 mm in part  1 and selecting define from part 1 in part 2. 

Here we are checking the Wall Thickness to 1 mm.

Finally we are defining the Initial State Name and defining the Pressure = 1 bar, Temperature  = 300 K and Composition = Air.

Intake Pipe Section 2

The Intake Pipe Section 2 is first cut using the Pipe Normal Cutting plane in the convert tab.

This is the end result of the cut plane. 

Right click to Convert Shape to Component.

Select flow Volume to PIPE.

Next is to select  Bend Type - Straight . Next is define diameter by Measured Effective Diameter = 63.694 mm in part 2 and selecting define from part 2 in part 1. 

Here we are checking the Wall Thickness to 1 mm.

Finally we are defining the Initial State Name and defining the Pressure = 1 bar, Temperature = 300 K and Composition = Air.

Intake Pipe Section 1 Connections

Right click to Add Connections.

Select Ports as Port 1 and connection as GEMsubAsstExtConn.

Select flow direction as Inlet and asign port ID as 5. 

Intake Pipe Section 3

 

The Intake Pipe Section 3 is first cut using the 3 point Cutting plane in the convert tab.

This is the end result of the cut plane.

Right click to Convert Shape to Component.

Select the flow volume to Flow Split

Now the flow split type is selected as General

After the conversion we get the geometry of the section.

Finally we are defining the Initial State Name and defining the Pressure = 1 bar, Temperature = 300 K and Composition = Air.

Main Section 

The Main Section  is first cut using the 3 point Cutting plane in the convert tab on one side.

The Main Section is first cut using the 3 point Cutting plane in the convert tab on the other side.

The bottom shows the three different colour sections.

Right click on one section to Convert Shape to Component.

Select the flow volume as Flow Split

Select the flow split type as General.

After the conversion we get the geometry of the section.

Finally we are defining the Initial State Name and defining the Pressure = 1 bar, Temperature = 300 K and Composition = Air.

Main Section Middle 

Now we have selected the middle part of the main section.

Select the flow volume as Flow Split

Select the flow split type as General.

After the conversion we get the geometry of the section.

Finally we are defining the Initial State Name and defining the Pressure = 1 bar, Temperature = 300 K and Composition = Air.

Flow Connection

The following is to make a flow connection in the flow tab. This is done for patching the two pipes together..

Below we can see that the some of the two pipes pf different lengths are patched. 

Next is the Extruded Connection which done for main section and the pipe. Here we can see the light patch between the pipe and the main section.  

Export Model

The intake maniflod has to oriented in the right way to form a 1D view in the GT suite. Then the click the Export The GT Model

Then click Discretize and a tab opens the select Open in GT-Suite.

Here we can that the model has been exported from the GEM 3D Model. If we want we can arrange the model to be more clear.

This is the rearranged model with clear paths of connection. 

Conclusion

• For the Discretization Simulation the changing its discretization length from 40 mm to 0.1 mm the simulation time has increased exponentially. There is also very little deviations in the results when compared to the case 2.
• Thus we have performed the Intake Manifold build using the STL file.