Learning Forum

[Usman]

Hello,

 

I hope you are fine. Can anyone please let me know what is the procedure to create engine model with own dimensions?

Also, I am practicing system coupling tutorial, however, it stays at 0%. Anyone here had the same issue? How it can be sorted out?

 

Many thanks!

Warm regards,

Muhammad Akhtar

[Rahul]

Hi Muhammad,

The geometry can be modified within the Forte UI to a certain extent using "Transform Mesh". If a much larger bore is needed, you can first scale the whole geometry along desired direction(s) first and then scale the "liner" and "piston" surface. To adjust the Compression Ratio (CR) after the adjustment to bore and stroke, the Piston surface can be moved up or down to increase/reduce the CR. The CR can be checked using the CR utility on the menu bar. 

Is it stucked there for a long time? Please check the participant transcript file to see if it is solving the first coupling iteration.

[Usman]

Could you please show me in a figure how to modify a geometry to own dimesions? It will be much appreciated. My university has 1 cylinder C.I. engine with one inlet and one outlet valves. 

Warm regards,

[Rahul]

For example, the two figures below show the original geometry and a modified one in which the piston and liner surfaces are scaled along the x and y directions by a factor of 1.2. If you try a much larger value, for example, 1.5, you'll see that some of the triangles on the symmetry plane start to become inverted because of excessive stretching. If a much larger bore is needed, you can first scale the whole geometry along desired direction(s) first and then scale the "liner" and "piston" surface.

[Usman]

Hi,

Thank you for your reply. However, your figures are not loading. I cannot see any of your attached figure.

[Rahul]

Check it here again.

[Usman]

Still the same issue. Also, I could not find the "Transform Mesh" option in ANSYS Forte. Could you please email me those figures and general steps on how to create own CAD model for engine simulations in ANSYS Forte? My email is Muhammadusmansaeed.Akhtar@hud.ac.uk. It will be much appreciated.

[Usman]

Could you please update me?

[Rahul]

Hi

Ansys Employee (for Forum discussions) we cannot share it over email to you. Please try using different browser to access this thread to see the attached images.

[Usman]

Hello, I have tried other browsers as well, however, I am having the same issues. Could you please upload them in JPEG format? I have attached the snapshot of what shows when I open your figures.

[Usman]

Hi,

Could you please update me? I am really worried. I need to model engine with my own dimensions for my PhD. I could not find transform mesh option in Ansys forte. and How I can create my model in Ansys forte?

[Usman]

Hello, I successfully scaled the model as per required dimenssions, however, when I check the compression ratio it comes to be -547.8555456341 (See Figure below). Could you please let me know what can be the issue?

[Usman]

Hello team,

 

I managed to change the stroke and bore, however, I was unable to increase the compression ratio. I have tried everything, but it is not affecting it. Could you please suggest me how to change it?

 

[SVV]

Hi,

 

You can use the CR calculator to design your engine. Please refer to the following user manual page for more infromation 2.8.15. Compression Ratio Calculator (ansys.com)

[Usman]

Thank you for your response. Yes, I am using it to calculate my CR, however, please suggest me how i can increase it?

[SVV]

In Forte, compression ratio is computed as the ratio of the mesh volumes at the piston bottom dead center and topped at center locations. Hence you can change your chamber volume or piston position accordingly.  For example, move the surface of piston upward if you want to increase SR. 

[Usman]

I tried to move piston, however, it is not affecting compression ratio. Stroke size is also not affecting it. Could you please let me knoe how I can change chamber volume?

[Usman]

Also, when I try full cycle engine tutoral, it says "Egress has failed" and then it starts the simulation. Could you please let me know about this issue, does it impacts results? Also, please update me about CR. I am very worried because of it.

[Usman]

Hello,

I hope you are fine. I have modified the sector mesh to the dimensions I have, using the transform mesh. Also, I changed the bore, stroke and con rod dimensions in the boundary conditions of the piston. However, When I try to check the CR, it shows an error (See Figure below):

Also, it has been set up to run from -22 to 22 degrees crank angle. I need to run it from 132 to 852. Could you please let me know how I can adjust the crank angles?