https://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/en-USTelligent Community 13https://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/f/actranTue, 29 Sep 2026 14:42:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:596e808c-c9aa-45a2-8adf-011158132be7https://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/Tue, 29 Sep 2026 14:42:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:3309e10a-759e-41ee-bc0e-572077694604https://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/f/actran/74125/radiosity-vs-ray-tracing-methods-interns-of-the-acoustic-applications/1432829Mon, 31 Aug 2026 11:13:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:1e266f59-49db-44bd-ba8a-3bac0e727a67Joseph OrselliHi Hemanta, Thanks for the good question. As for the SEA solutions that are being proposed by Actran, one involves building an SEA model from FEM models, which has plenty of benefits, but still requires FEM solutions under the hood. This technique is the so-called Virtual SEA analysis in Actran, and while its great for not building your model from scratch but from a FEM solution, it will still only be appropriate for mid-frequency problems where the FEM models run. For higher frequencies, the radiosity solution is more advantageous. If we only consider the pure TL based SEA solution in Actran Workflowmanager interface, it is more similar to radiosity. One of the advantages that radiosity offers is that it can more effectively be used for modelling open space radiation problems, and it offers a continuous evolution of pressure in space whereas the space averaging over SEA subsystems means that in our TL based SEA solution you only achieve a single mean square pressure or dB reading per subsystem. If you want a more continuous solution, radiosity is the way to go. If you have further background questions, I would encourage you to get in touch with our support team or checkout our e-Learning material to learn more about the SEA solutions + radiosity in Actran. Thanks!https://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/f/actran/74125/radiosity-vs-ray-tracing-methods-interns-of-the-acoustic-applications/1432828Sun, 30 Aug 2026 08:24:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:212d3fee-3b85-4956-bc43-55987ec7c2cbHemanta DikshitHello Praveen, It is a good summary of the comparison between the radiosity solver and ray acoustics. The radiosity solver is based on energy exchange between surfaces. SEA is also an energy-based solver, where the system is divided into multiple subsystems. I was wondering what the benefits and limitations of the radiosity solver are compared to the SEA approach. In particular, it would be interesting to understand where the radiosity solver has an advantage over SEA and where SEA might be more appropriate. Thank you!https://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/f/actran/74332/problem-defining-an-impedance-boundary-condition/1432826Mon, 24 Aug 2026 03:10:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:bb2e901b-91f2-4f2c-8b03-dcc49bbb1b43Joseph OrselliHi Santiago, I see you wrote us at support - let's continue our conversation there. Nevertheless, please find my copy-paste answer here, it might be useful to others in the forum. My advice would be to use our GUI, ActranVI, in order to generate surface elements from the 3D elements of the treated duct. Then you, have a proper application of the boundary condition, rather than trying to connect a boundary condition to its analysis component via an interface (illegal in our FEM modelling). To do this, import your volume cylinder CAD in ActranVI, then CNTRL click it to highlight it red. You can then use the Mesh --> Surface --> Skin tool to get the surface 'skin' elements of the cylinder. Once you've got that, you can hide the volume cylinder to visualize just the skin. Change to element selection mode and CNTRL click the elements you want to apply your impedance BC on to select them. Once selected, use the Mesh --> Edit --> Move/copy tool to add them to a new PID. Once this is built, you can add the new impedance element collection to a domain and assign it to your BC in the analysis. The surface elements will be congruent (share nodes) with the cylindrical volume of your duct, so this setup is OK!https://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/f/actran/74332/problem-defining-an-impedance-boundary-conditionFri, 21 Aug 2026 05:34:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:14475e86-6e42-4137-8c00-8378080eac89Santiago Montoya OspinaHello, I am having problems defining an impedance BC where I want to simulate a portion of treated duct to calculate the transmission loss. I basically have a cylindrical duct on which I create a patch surface in CAD. When I import the CAD in Actran I have to parts: The volume and the surface patch. I create the meshes for both parts and apply an interface to match the different meshes, but I am still getting the following error: I have tried with different tolerance values. Is there a way to directly partition the surface in Actran or what else can I do? Thanks in advance.Actranhttps://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/f/actran/74327/2d-wave-number-filtering-techniques-for-separation-of-turbulent-wall-pressure-and-acoustic-pressure-on-the-surface-of-structure/1432822Mon, 17 Aug 2026 15:05:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:bbad0745-5126-4804-a67f-e71947f8ac45Anup PaulHi Padmanabham, please follow Joe's recommendation above. I just want to clarify the website & email address to contact our technical support team. Preferred contact method is https://simcompanion.hexagon.com/ , you can register for an account using your license information if you have no already done so. Alternatively, you can email actran.support@mscsoftware.com .https://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/f/actran/74327/2d-wave-number-filtering-techniques-for-separation-of-turbulent-wall-pressure-and-acoustic-pressure-on-the-surface-of-structure/1432819Mon, 17 Aug 2026 03:44:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:6917bbb4-66b7-4411-9bb6-f85078cc572dJoseph OrselliHi Padmanabham - if you open a support request via SimCompanion (or write us a mail) and detail what you are trying to achieve, I would be happy to provide some guidance or examples. Thanks, it really helps us ensure that we don't lead you on a wild goose chase if the methods you are asking about are not the best solution for your actual application.https://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/f/actran/74328/calculation-of-dry-modes-vs-wet-model-of-partially-filed-body-and-fully-submerged-body/1432818Mon, 17 Aug 2026 03:40:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:cbc9fd94-5b32-45fa-ace2-bc1ac01745d4Joseph OrselliThe COUPLED_MODAL_EXTRACTION analysis type starts from a computation of the structures natural frequencies 'in-vacuo', and then accounts for the added mass and stiffness of the fluid by adapting the natural frequencies computed accordingly. I think the demo you include a link to is a great place to start, but I would really recommend reading chapter 47 of the user guide volume 1 to understand the theoretical aspects of how this is done. (it is brief ) If you have further questions about building or debugging your COUPLED_MODAL_EXTRACTION analysis, I think reaching the support via SimCompanion is the way to go!https://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/f/actran/74328/calculation-of-dry-modes-vs-wet-model-of-partially-filed-body-and-fully-submerged-body/1432815Sun, 16 Aug 2026 07:08:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:c969d2e1-4bb9-46fa-866e-02159b66b82fpadmanabham madathalaThank you for response. my point is , how to account virtual mass due fluid loading like water ,as you know , the fluid load will influence my natural frequency estimation. how to calculate?. https://simcompanion.hexagon.com/customers/s/article/Demonstration-Model-Submerged-propeller .https://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/f/actran/74327/2d-wave-number-filtering-techniques-for-separation-of-turbulent-wall-pressure-and-acoustic-pressure-on-the-surface-of-structure/1432814Sat, 15 Aug 2026 05:08:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:1c16d1ce-6225-4feb-a464-4883270ca96dpadmanabham madathalaThank you for response . i have gone through the document -chapter 59, but my understanding , the procedure not much clear. can i have any tutorial case study, with step by step procedure along with dummy data set, so that, i can become more familiar and better understanging the tool . looking forward for tutorial case study.https://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/f/actran/74328/calculation-of-dry-modes-vs-wet-model-of-partially-filed-body-and-fully-submerged-body/1432811Wed, 12 Aug 2026 03:39:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:8c8eb682-4582-4139-aeff-4c903201c1bfJoseph OrselliHi Padmanabham - to compute dry modes of a structure use the Actran Modal Extraction analysis. (or Nastran, much more efficient for modal extractions!) For fully submerged bodies, you can try the Actran coupled modal analysis. For tanks either fully or partially filled, or for partially submerged bodies, I think you will need to consider another solution. I think that Nastran has some efficient tools for modelling modal computations of structures coupled with heavy fluids that you could give a try. Radiation efficiency of structures is available in Actran 2026.1, if you have a specific case where you are not able to achieve a radiation efficiency output, I encourage you to write us at support so we can debug together. Thanks!https://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/f/actran/74327/2d-wave-number-filtering-techniques-for-separation-of-turbulent-wall-pressure-and-acoustic-pressure-on-the-surface-of-structure/1432810Wed, 12 Aug 2026 03:35:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:9ba3696c-c071-4493-bb04-55396ce6d1d1Joseph OrselliHi Padmanabham - yes the wave number decomposition technique for pressure on structure exists - you can check out the user guide volume chapter 59 on pressure decomposition. Please come back if it is not what you were looking forhttps://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/f/actran/74326/how-to-apply-vibration-acceleration-either-in-psd-m-s2-2-hz-or-rms-m-s2-as-load-excitation-at-node-point-of-structure-and-predict-the-vibration-of-structure-accelerations-at-the-reaming-nodes-how-to-plot-the-results-the-accel/1432809Wed, 12 Aug 2026 03:18:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:22ed576d-c6e2-43c7-b154-d5f48e01ecd4Joseph OrselliHi Padmanabham, I hope you find the following answers to your questions useful: 1) Depends what excitation you are trying to apply, it is not clear to me from your question what you are studying. Can you provide more information on what you are trying to model? Some excitation in Actran are random , like the diffuse sound field, and users provide a PSD spectrum, and results are PSD as well. Other excitations are deterministic, and if you have a RMS measurement from a capture device you can apply it directly in the excitation BC, so long as you are consistent in your pre and post processing. To get results on computational nodes, use an Output Map request. 2) You can manipulate raw data however you like in PLTViewer interface using drag and drop and a combination of numpy + PLTViewer built in functions. Here is how to plot dB pressure expanded, if you wanted to change your reference you would just change the denominator here: 3) You can check out chapter 53.11 of Actran user guide volume 1 to see the TURBULENT_PARAMETERS datablock of ICFD, which does exactly what you are asking. Once you have the output information on an NFF file, you can refer to these inside the TBL load excitation within your Actran anaylsis If you have more in depth questions / need help debugging your analyses, I encourage you to reach us at our support mail, we can provide specific help for your setup rather than general answers appropriate for the forums.https://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/f/actran/74328/calculation-of-dry-modes-vs-wet-model-of-partially-filed-body-and-fully-submerged-bodyWed, 05 Aug 2026 16:16:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:0ab36067-abd4-47a1-940a-ceb11907cfb3padmanabham madathalacalculation of dry modes vs wet model of partially filed body and fully submerged body in actran ? how to calculate both dry modes vs wet model of partially filed /submerged body and fully submerged body ? why r adiation efficiency of structure not available in actran 2026 ?https://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/f/actran/74327/2d-wave-number-filtering-techniques-for-separation-of-turbulent-wall-pressure-and-acoustic-pressure-on-the-surface-of-structureWed, 05 Aug 2026 16:08:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:cec48b0f-f332-45e3-945d-981ce84f4babpadmanabham madathaladoes 2d wave number filtering techniques available in ICFD tool to apply on the transient cfd model for separation of turbulent wall pressure and acoustic pressure on the surface of structure ?https://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/f/actran/74326/how-to-apply-vibration-acceleration-either-in-psd-m-s2-2-hz-or-rms-m-s2-as-load-excitation-at-node-point-of-structure-and-predict-the-vibration-of-structure-accelerations-at-the-reaming-nodes-how-to-plot-the-results-the-accelWed, 05 Aug 2026 15:55:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:3b3a4d3c-d82d-4449-970c-05a64d82fb30padmanabham madathala1. how to apply vibration acceleration either in psd ((m/s2)2/Hz) or rms(m/s2) as a load excitation at node/point of structure and predict the vibration of structure accelerations at the other nodes?(acceleration input and accelration output) 2. how to plot the result acceleration data in db scale with reference 1e-5m/s2 . unfortunately only sound pressure 20u pa reference option available 3. how to get tbl parameters from study RANS cfd data by using the icfd tool. and consequently these outputs, from the icfd i would like to apply as a load on elastic structure ?https://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/f/actran/74312/field-pressure-map-results-interpretation/1432800Mon, 03 Aug 2026 06:49:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:6e26f533-83ee-4640-b101-03271f37cbf8Joseph OrselliHi Dilan, just to add to Praveen's answer, normally when running an analysis with Random Excitations (Diffuse sound field, for example) Actran outputs two files for any output requested (maps + FRF curves in plt file format). This is the field.nff and field_psd.nff you are getting. The diffuse sound field (DSF) is generated via a sampling approach. This means you have defined a number of samples (typically 30 because of Central Limit Theorem) and the excitation is in reality 30 individual deterministic loadings that considered in isolation are not particularly meaningful, but considered together in a statistical sense satisfy the mathematical definition of what a Diffuse Sound Field is. Each individual sample is a different loadcase passed to the solver, and the response to all the individual loadcases are output in field.nff. field_psd.nff on the other hand applies a Power Spectral Density operator on the results in field.nff . In practice, this operation is essentially a sum of squares average for each loading, as per our ActranVI user guide. For indicators that are already quadratic (think acoustic radiated power, or mean square pressure, for instance), this is just an average of all loadcases. For typical industrial and engineering applications, only field_psd.nff needs to be considered. If you are performing some academic research into unusual statistical analysis + random excitations in numerical methods, then the field.nff can be analyzed with your own post processing operations. In my daily work, I just consider it an intermediary result.https://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/f/actran/74312/field-pressure-map-results-interpretation/1432781Fri, 17 Jul 2026 14:37:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:9f6b36d1-93ae-48d5-afbf-c67410a50f47Praveen JayasheelaHi Dilan, field.nff This file represents an output field map on the actual finite element mesh used in the Actran computation. It provides a color map visualization of a result quantity (e.g., pressure, displacement) across the computational domain for specific frequencies. Use this when you want to visualize results directly on the mesh that participated in the simulation, such as structural or cavity meshes. field_psd.nff This file represents an output field map on a post-processing mesh, which is different from the computational mesh. The post-processing mesh (sometimes called a dummy mesh) does not participate in the computation. It is used solely for plotting contour maps, often in regions like the acoustic far field. Use this when you need to visualize results (e.g., acoustic pressure distribution) in areas outside the main computational domain, such as in the far field or on a special observation surface. I hope this helps! -JPhttps://community.cadence.com/cadence_technology_forums/physical-system-simulation/actran/f/actran/74312/field-pressure-map-results-interpretationThu, 16 Jul 2026 05:51:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:cc03379d-a948-4a17-b464-c3591c5b19d0D CarpanenHello, I have two types of field output map generated. One is field.nff and the other one is field_psd.nff Could you please help me understand the difference between the two and when to use each cases? Thank you!fieldmapActran