Discretization of Intake manifold using GT Gem 3D

AIM

      The objective of the project is to compare the results by varying the discretization length and convert the 3D model to the 1D model for an intake manifold.

Model 

The discretization length is set as a parameter in which the default value is set to the 0.4*length and in case 2 value is set to 0.1.

Results

The decrease in the discretization length increases the number of subvolumes in the flow domain hance it captures the data more accurate so the total time of the simulation increases by a very large extent and the value of the engine parameter vary by a small value which has no significant effect.

 Building Intake manifold

Open GT - Gem 3D application, home --> open --> C --> program files x86 --> GTI --> v2019 --> examples --> acoustics --> non linear --> plenum.

The model is divided into different sections where there is a variation of the curve by 90 deg by using the option. Convert --> Select surface --> separate by curve & now select all the opening surface & delete it.

Use 3 point cutting plane option under convert option to separate the plenum from the manifold. 

We have covert all the pipes to a uniform diameter, select pipe --> convert shape to component.

The flow volume is decided by the selected object in our case it is pipe. The number of the pipe is decided from the flow direction of 1 --> 2.

The bent type for the flow volume is selected since the pipe is not in a single plane it has several bends so multiple bends option is chosen the uniform dia value for the pipes are provided.

The wall thickness for the pipe is provided as 1.

The initial state of the flow is selected from the predefined data available.

The similar steps are followed for the other pipes and required values are provided.

The top of the intake pipes is divided into three sections using the cut plane option. Then convert shape is used to convert them into uniform sections.

Select pipe --> Add connection --> select port depending on the flow direction.

Flow --> connection --> flow connection, this option is used to connect simple connection is the bend or the distance between the pipes are more then,  flow --> connection --> extruded connection is used.

After connecting the pipes orient the model in proper & use the export GT model option under the home menu and select the discretize option which converts the 3D model into the 1D model.

Delete the SA conn & add the required flow volume and run the simulation to obtain the required results.