could anybody kindly help me to run my model? getting error 2331 (FEKO 2023.1)

sswh2
sswh2 Altair Community Member
edited December 5 in Community Q&A

Hello I am getting an error message, could anybody kindly help me to run my model? I am attaching here my design model, it is created in FEKO 2023.1 Thanks in advance!

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Best Answers

  • Evan_Urban
    Evan_Urban
    Altair Employee
    Answer ✓

    I took a quick look at your model. I noticed your feed is extruding out of the cylinder (I do not believe this is what you desire(?)). This may be the reason as to why your S11 looks like it is. If you want your feed to touch both the inner and outer portions of the cylinder but keeping the radius 0.6, then you may want to follow constructing a cylinder with an edge port for the feed.

  • Evan_Urban
    Evan_Urban
    Altair Employee
    Answer ✓

    Sure, please give me some time and I will post a modified geometry for you.

    Respectfully,
    Evan Urban

  • Evan_Urban
    Evan_Urban
    Altair Employee
    Answer ✓

    Ahh, I apologize, I missed that in the title. Let me redo.

  • Evan_Urban
    Evan_Urban
    Altair Employee
    Answer ✓

    Here is the modified file in 2023.1 version. I am looking forward to hearing your thoughts.

  • Evan_Urban
    Evan_Urban
    Altair Employee
    Answer ✓

    Considering the resonance, I cannot say much for the theoretical aspect, I apologize (may be due to creeping waves).

    However, with the model I had provided you, Feko is giving accurate results. If you need to alter the position of the cylinder, keep in mind that both ends need to touch the PEC of the inner and outer full cylinder (May be good to separate the geometries and reunion after manipulations). Additionally, for the Edgeport, there has to be a small gap where the edgeport is placed within Freespace (There is a very small cylinder around the Edgeport in your model). With this in mind, you can maneuver the feed around to your desired position. Feel free to reach out if you are having issues regarding this.

  • Evan_Urban
    Evan_Urban
    Altair Employee
    Answer ✓

    That is interesting. I tried this on my end and did not get any error. But with this model I am receiving that error. I am looking into this in detail for you.

  • Evan_Urban
    Evan_Urban
    Altair Employee
    Answer ✓

    I changed the feed_rad back to 0.6 and ran the simulation, no errors appeared. I had rechanged the feed_rad back to 0.65, and now my simulation is running without an error. I am unsure why but I will look into reporting this as a bug in Feko.

  • Evan_Urban
    Evan_Urban
    Altair Employee
    Answer ✓

    The reason for that is to define the Edgeport. To create an Edgeport you have to have the same media on both sides. So, in this case, I needed to create a small gap from the Edgeport to meet that criteria. I arbitrarily chose 0.05, you can change this as you want as long as it is there, but it is necessary to create the port.

Answers

  • Evan_Urban
    Evan_Urban
    Altair Employee

    Hello,

    It appears in your model you have two overlapping geometries, Unioning both your geometries together will solve this error.

    After unioning I am getting another error the wire radius to length is too large. Thin wire approximation in Feko requires the radius of the wire to be 1/3 of the length of the wire. For example, if the length of your feed is lambda/10, your radius should be lambda/30. Not sure what radius you prefer in your simulation; I noticed for your mesh settings you have it set to 0.0000000001e-4 (Possibly mean 1e-4?), but locally on the wires you have 0.6. If you set the radius to 1e-4mm no errors are thrown.

    I look forward to hearing back from you, hope this helps!

    Respectfully,
    Evan Urban

  • sswh2
    sswh2 Altair Community Member

    @Evan_Urban sir, I got the same error after union operation, I need the wire radius 0.6, then how can I fix this error

    the ratio of wire radius to length is too large?

  • Evan_Urban
    Evan_Urban
    Altair Employee

    Instead of a wire, you can use a cylinder and then assign an Edgeport on it for excitation. That helps fix that thin wire error though you will have to mesh the cylindrical geometry. Please let me know if you have any more questions or need further clarification.

    Respectfully,

    Evan Urban

  • sswh2
    sswh2 Altair Community Member

    @Evan_Urban sir, I made the wire length long like -4 to 4mm , radius still 0.6mm, then there is no error, but I am getting S11 like this , may be because of the creeping waves in dielectric coated cylinder, do you think it is for port?

  • Evan_Urban
    Evan_Urban
    Altair Employee

    Hello,

    Is your feed connecting from the inner radius of your structure to the outer? Can you provide your updated model so I can check everything for you? If there are no errors or warnings, then the results you see may be due to creeping waves, but I can check closer with your model.

    Respectfully,
    Evan Urban

  • sswh2
    sswh2 Altair Community Member
    edited December 9

    Sir, here it is, kindly check and tell me why s11 is like this

  • Evan_Urban
    Evan_Urban
    Altair Employee
    Answer ✓

    I took a quick look at your model. I noticed your feed is extruding out of the cylinder (I do not believe this is what you desire(?)). This may be the reason as to why your S11 looks like it is. If you want your feed to touch both the inner and outer portions of the cylinder but keeping the radius 0.6, then you may want to follow constructing a cylinder with an edge port for the feed.

  • sswh2
    sswh2 Altair Community Member

    @Evan_Urban sir, I can't pick face in the cylinder to create edge port, can you kindly make the cylinder port in my model and attach here? Thanks!

  • Evan_Urban
    Evan_Urban
    Altair Employee
    Answer ✓

    Sure, please give me some time and I will post a modified geometry for you.

    Respectfully,
    Evan Urban

  • sswh2
    sswh2 Altair Community Member

    Thanks sir! I will wait for your modified probe model

  • Evan_Urban
    Evan_Urban
    Altair Employee
    edited December 9

    Hello,

    Here is the modified model I worked on. I hope this is more towards what you are looking for. I set the frequencies to 31 frequency points to make it run a bit quicker on my end. I look forward to hearing your thoughts.

    Respectfully,
    Evan Urban

  • sswh2
    sswh2 Altair Community Member

    Sir, I can't open or run this file as my FEKO is 2023.1, please send me 2023.1 model

  • Evan_Urban
    Evan_Urban
    Altair Employee
    Answer ✓

    Ahh, I apologize, I missed that in the title. Let me redo.

  • Evan_Urban
    Evan_Urban
    Altair Employee
    Answer ✓

    Here is the modified file in 2023.1 version. I am looking forward to hearing your thoughts.

  • sswh2
    sswh2 Altair Community Member

    @Evan_Urban sir thank you so much, now the result s11 is like this, I think I have to change probe location, cylinder radius to get good s11 bandwidth, now it confirms I think s11 has multiple resonances less than my simulated first case due to creeping waves. What do you think about this multi-resonance?

  • Evan_Urban
    Evan_Urban
    Altair Employee
    Answer ✓

    Considering the resonance, I cannot say much for the theoretical aspect, I apologize (may be due to creeping waves).

    However, with the model I had provided you, Feko is giving accurate results. If you need to alter the position of the cylinder, keep in mind that both ends need to touch the PEC of the inner and outer full cylinder (May be good to separate the geometries and reunion after manipulations). Additionally, for the Edgeport, there has to be a small gap where the edgeport is placed within Freespace (There is a very small cylinder around the Edgeport in your model). With this in mind, you can maneuver the feed around to your desired position. Feel free to reach out if you are having issues regarding this.

  • sswh2
    sswh2 Altair Community Member

    @Evan_Urban sir thank you so much! sure if I need further assistance to move my probe, I will contact you again.

  • sswh2
    sswh2 Altair Community Member

    @Evan_Urban sir I am getting error, while I am trying to make variable feed_rad=0.65mm, just changing variable gives me this error

  • Evan_Urban
    Evan_Urban
    Altair Employee
    Answer ✓

    That is interesting. I tried this on my end and did not get any error. But with this model I am receiving that error. I am looking into this in detail for you.

  • Evan_Urban
    Evan_Urban
    Altair Employee
    Answer ✓

    I changed the feed_rad back to 0.6 and ran the simulation, no errors appeared. I had rechanged the feed_rad back to 0.65, and now my simulation is running without an error. I am unsure why but I will look into reporting this as a bug in Feko.

  • sswh2
    sswh2 Altair Community Member

    @Evan_Urban sir thanks, when I made feed rad=0.65mm+0.05+0.05 there is no error, can you kindly tell me why you put another cylinder thicker than the feed radius in the middle? I have to change the probe location, so I have to know how did you put these values for the middle cylinder?

  • Evan_Urban
    Evan_Urban
    Altair Employee
    Answer ✓

    The reason for that is to define the Edgeport. To create an Edgeport you have to have the same media on both sides. So, in this case, I needed to create a small gap from the Edgeport to meet that criteria. I arbitrarily chose 0.05, you can change this as you want as long as it is there, but it is necessary to create the port.

  • sswh2
    sswh2 Altair Community Member

    @Evan_Urban sir thanks for the nice explanation!

  • Evan_Urban
    Evan_Urban
    Altair Employee

    Not a problem at all!