# Applications **URL:** https://bempp.discourse.group/c/applications/8.md?page=1 [Latest](https://bempp.discourse.group/latest.md) · [Categories](https://bempp.discourse.group/categories.md) **Page:** 2 --- ## [How to specify boundary conditions when multiple objects share boundary?](https://bempp.discourse.group/t/how-to-specify-boundary-conditions-when-multiple-objects-share-boundary/181)
**Author:** [@Kris](https://bempp.discourse.group/u/Kris)\ **Replies:** 0\ **Last updated:** [20 March 2023 07:18 UTC](https://bempp.discourse.group/t/how-to-specify-boundary-conditions-when-multiple-objects-share-boundary/181 "2023-03-20T07:18:00Z")
For example, consider the problem of finding the electric potential (Laplace problem) inside 2 concentric dielectric spheres of different conductivities ε1 and ε2 outside and inside respectively (homogeneous, isotropic w… --- ## [Unbaffled plate acoustic radiation](https://bempp.discourse.group/t/unbaffled-plate-acoustic-radiation/119)
**Author:** [@MattC](https://bempp.discourse.group/u/MattC)\ **Replies:** 3\ **Last updated:** [10 March 2023 10:37 UTC](https://bempp.discourse.group/t/unbaffled-plate-acoustic-radiation/119 "2023-03-10T10:37:49Z")
Dear Bempp users, I would to simulate the radiation of an unbaffled rectangular thin plate under motion below 1Khz. To do so, I defined a velocity field on both rectangle faces, as follow: plate = bempp.api.shapes.cub… --- ## [Creation of empty grid](https://bempp.discourse.group/t/creation-of-empty-grid/170)
**Author:** [@marc.jofre](https://bempp.discourse.group/u/marc.jofre)\ **Replies:** 2\ **Last updated:** [24 January 2023 19:12 UTC](https://bempp.discourse.group/t/creation-of-empty-grid/170 "2023-01-24T19:12:02Z")
Hi all, Could it be possible to initialize and empty grid? For spaces like: grid=Empty ??? div\_space = bempp.api.function\_space(grid, “RWG”, 0) curl\_space = bempp.api.function\_space(grid, “SNC”, 0) --- ## [Can bempp-cl be used to solve large size Maxwell's problems?](https://bempp.discourse.group/t/can-bempp-cl-be-used-to-solve-large-size-maxwells-problems/166)
**Author:** [@jntu2023](https://bempp.discourse.group/u/jntu2023)\ **Replies:** 0\ **Last updated:** [6 January 2023 19:38 UTC](https://bempp.discourse.group/t/can-bempp-cl-be-used-to-solve-large-size-maxwells-problems/166 "2023-01-06T19:38:15Z")
While learning to use bempp-cl, I encountered a number of problems. I have posted segmentation faults problem when running EM tutorial example. One response is that using opencl to fix the problem. For large problem, sa… --- ## [Input impedance patch antenna vs. feed point - example](https://bempp.discourse.group/t/input-impedance-patch-antenna-vs-feed-point-example/164)
**Author:** [@marc.jofre](https://bempp.discourse.group/u/marc.jofre)\ **Replies:** 1\ **Last updated:** [4 January 2023 18:15 UTC](https://bempp.discourse.group/t/input-impedance-patch-antenna-vs-feed-point-example/164 "2023-01-04T18:15:53Z")
Hi, Below I attach the code and results (it can be improved) when experimenting with computing the input impedance of a patch antenna - assuming a feed point/probe model. The resistance part should follow cos^2(distance… --- ## [Source driven problem using Method of Moments](https://bempp.discourse.group/t/source-driven-problem-using-method-of-moments/40)
**Author:** [@rsends](https://bempp.discourse.group/u/rsends)\ **Replies:** 6\ **Last updated:** [31 December 2022 12:36 UTC](https://bempp.discourse.group/t/source-driven-problem-using-method-of-moments/40 "2022-12-31T12:36:32Z")
Hello, I am attempting to solve the following problem where I have a microstrip, and I excite the edge m using method of moments (MoM) . This is related to a previous post but it is a different question, which is why I … --- ## [Electromagnetic Source driven with dielectric - Patch antenna](https://bempp.discourse.group/t/electromagnetic-source-driven-with-dielectric-patch-antenna/160)
**Author:** [@marc.jofre](https://bempp.discourse.group/u/marc.jofre)\ **Replies:** 2\ **Last updated:** [28 December 2022 20:43 UTC](https://bempp.discourse.group/t/electromagnetic-source-driven-with-dielectric-patch-antenna/160 "2022-12-28T20:43:18Z")
Hi, I try to model electromagnetic radiation from a patch antenna. In particular, I am not sure on the considerations for computing correctly the fields when a dielectric is present. Would appreciate help on the defini… --- ## [How to use BEMPP for Source Driven EM Problems](https://bempp.discourse.group/t/how-to-use-bempp-for-source-driven-em-problems/25)
**Author:** [@rsends](https://bempp.discourse.group/u/rsends)\ **Replies:** 14\ **Last updated:** [15 October 2020 08:46 UTC](https://bempp.discourse.group/t/how-to-use-bempp-for-source-driven-em-problems/25 "2020-10-15T08:46:57Z")
Hey, I am new to BEMPP, and I am trying to solve a driven source problem. Specifically, I am trying to define a source at a specific edge of the mesh of my geometry. How would I go about and identifying the edge to fla… --- ## [How to monitor convergence?](https://bempp.discourse.group/t/how-to-monitor-convergence/148)
**Author:** [@chellia](https://bempp.discourse.group/u/chellia)\ **Replies:** 2\ **Last updated:** [28 October 2022 20:21 UTC](https://bempp.discourse.group/t/how-to-monitor-convergence/148 "2022-10-28T20:21:47Z")
Hi. Thanks for the wonderful software. I am wondering if there is a way to monitor the convergence of the solver. I am solving a quite large problem (just a plane wave scattering problem on an object at 8kHz - it takes a… --- ## [Memory utilization for large problems](https://bempp.discourse.group/t/memory-utilization-for-large-problems/120)
**Author:** [@Fabian](https://bempp.discourse.group/u/Fabian)\ **Replies:** 1\ **Last updated:** [8 March 2022 09:49 UTC](https://bempp.discourse.group/t/memory-utilization-for-large-problems/120 "2022-03-08T09:49:56Z")
Hi everyone! I’m currently struggling with large acoustic problems. The number of nodes/elements yields to an overload of RAM. Is there any way to write matrix entries, e.g. from boundary operators, block-wise in temp… --- ## [How to calculate grid function value at arbitrary points](https://bempp.discourse.group/t/how-to-calculate-grid-function-value-at-arbitrary-points/117)
**Author:** [@piman](https://bempp.discourse.group/u/piman)\ **Replies:** 1\ **Last updated:** [8 March 2022 09:29 UTC](https://bempp.discourse.group/t/how-to-calculate-grid-function-value-at-arbitrary-points/117 "2022-03-08T09:29:47Z")
Hi all, I see bempp.api.GridFunction.evaluate\_on\_element\_centers() and bempp.api.GridFunction.evaluate\_on\_vertices() functions that evaluate the grid function value at the grid element centers and at the grid vertices. … --- ## [Sound emission from a mesh triangle or vertex](https://bempp.discourse.group/t/sound-emission-from-a-mesh-triangle-or-vertex/113)
**Author:** [@Gustavo](https://bempp.discourse.group/u/Gustavo)\ **Replies:** 0\ **Last updated:** [21 January 2022 10:17 UTC](https://bempp.discourse.group/t/sound-emission-from-a-mesh-triangle-or-vertex/113 "2022-01-21T10:17:41Z")
Hi, I am pretty new to BEMP, and probably this is a silly question, but is better to ask the experts than to be stuck on a loop of trial and error indefinitely… In this tutorial: Jupyter Notebook Viewer we have scatter… --- ## ['Field' in Bistatic RCS tutorial](https://bempp.discourse.group/t/field-in-bistatic-rcs-tutorial/111)
**Author:** [@DAWardle](https://bempp.discourse.group/u/DAWardle)\ **Replies:** 5\ **Last updated:** [20 January 2022 12:32 UTC](https://bempp.discourse.group/t/field-in-bistatic-rcs-tutorial/111 "2022-01-20T12:32:50Z")
Hi Bempp. Near the end of the Bistatic RCS tutorial there’s a line of code: exterior\_values = -epot0\_ext \* sol\[1\] - mpot0\_ext \* sol\[0\] I think exterior\_values is an array of electric field (E) values in the host medi… --- ## [The cause of Asymmetric Matrix in Bempp](https://bempp.discourse.group/t/the-cause-of-asymmetric-matrix-in-bempp/109)
**Author:** [@LCheng](https://bempp.discourse.group/u/LCheng)\ **Replies:** 5\ **Last updated:** [29 November 2021 13:09 UTC](https://bempp.discourse.group/t/the-cause-of-asymmetric-matrix-in-bempp/109 "2021-11-29T13:09:38Z")
I am studying the acoustic scattering simulation. I found that the assembled matrix is asymmetric for Bempp. But it is strange because the equation solved in \[BEM for Acoustic scattering \]((7) (PDF) Fast Methods applied … --- ## [Sound-hard Burton miller acoustic scattering](https://bempp.discourse.group/t/sound-hard-burton-miller-acoustic-scattering/45)
**Author:** [@Rasmus](https://bempp.discourse.group/u/Rasmus)\ **Replies:** 6\ **Last updated:** [10 November 2021 12:18 UTC](https://bempp.discourse.group/t/sound-hard-burton-miller-acoustic-scattering/45 "2021-11-10T12:18:44Z")
Hello First of all, thanks for making this software. I’m a masters student currently working with BEMPP to solve acoustic scattering problems off of a human head model to numerically calculate HRTF’s. As I have unders… --- ## [Restrict grid to particular segment](https://bempp.discourse.group/t/restrict-grid-to-particular-segment/97)
**Author:** [@DuncanvdH](https://bempp.discourse.group/u/DuncanvdH)\ **Replies:** 1\ **Last updated:** [16 September 2021 21:07 UTC](https://bempp.discourse.group/t/restrict-grid-to-particular-segment/97 "2021-09-16T21:07:57Z")
If I create a grid function for a particular function space on a segment of the grid, still the complete grid is visualized, although the grid function is only shown on the segment it is defined on. Is there a way to on… --- ## [Coefficients of composition of function and gridfunction](https://bempp.discourse.group/t/coefficients-of-composition-of-function-and-gridfunction/88)
**Author:** [@jnick](https://bempp.discourse.group/u/jnick)\ **Replies:** 2\ **Last updated:** [20 July 2021 13:04 UTC](https://bempp.discourse.group/t/coefficients-of-composition-of-function-and-gridfunction/88 "2021-07-20T13:04:29Z")
When implementing a solver for a nonlinear BIE formulation (by Newton’s method) I stumbled upon the following problem: Given a nonlinear function a:\\mathbb R^3\\rightarrow \\mathbb R^3 and coefficients c\\in \\mathbb R^{\\te… --- ## [The thread allocation issue related to the large-scale Problems](https://bempp.discourse.group/t/the-thread-allocation-issue-related-to-the-large-scale-problems/83)
**Author:** [@LCheng](https://bempp.discourse.group/u/LCheng)\ **Replies:** 2\ **Last updated:** [21 June 2021 03:34 UTC](https://bempp.discourse.group/t/the-thread-allocation-issue-related-to-the-large-scale-problems/83 "2021-06-21T03:34:10Z")
Hi, thanks for the very nice open source code. I am dealing with large-scale acoustic problems using Bempp-cl. Yesterday, when I tried the first benmark case with element number equal to 300 thousands, I am puzzled about… --- ## [Direction of RWG basis function in bempp](https://bempp.discourse.group/t/direction-of-rwg-basis-function-in-bempp/85)
**Author:** [@piman](https://bempp.discourse.group/u/piman)\ **Replies:** 1\ **Last updated:** [15 June 2021 08:30 UTC](https://bempp.discourse.group/t/direction-of-rwg-basis-function-in-bempp/85 "2021-06-15T08:30:59Z")
Hi all, To correlate RWG elements in bempp and in my own code, I’m interested in the order and direction of RWG basis function in bempp. As I can see, order of RWG elements is similar to the order of edges in grid.edges… --- ## [Well-conditioned formulation for open surfaces (Maxwell)](https://bempp.discourse.group/t/well-conditioned-formulation-for-open-surfaces-maxwell/75)
**Author:** [@piman](https://bempp.discourse.group/u/piman)\ **Replies:** 2\ **Last updated:** [28 May 2021 09:39 UTC](https://bempp.discourse.group/t/well-conditioned-formulation-for-open-surfaces-maxwell/75 "2021-05-28T09:39:11Z")
Hi all, I seek a well-conditioned formulation for electromagnetic scattering on a perfectly conductive screens. In \[1\] it is proposed several well-conditioned formulations, but as I can see they work only for closed sur… --- ## [Scattering by infinitely long bodies](https://bempp.discourse.group/t/scattering-by-infinitely-long-bodies/71)
**Author:** [@Varoloc](https://bempp.discourse.group/u/Varoloc)\ **Replies:** 0\ **Last updated:** [6 April 2021 16:42 UTC](https://bempp.discourse.group/t/scattering-by-infinitely-long-bodies/71 "2021-04-06T16:42:44Z")
Dear bempp-cl team, I have been trying to implement plane wave scattering by infinitely long bodies using G(x,y)=\\frac{j}{4}H\_{0}^{(2)}(k\_{b}|x-y|) instead of the Green’s function of a three-dimensional Helmholtz proble… --- ## [Alternative formulation of Maxwell equation](https://bempp.discourse.group/t/alternative-formulation-of-maxwell-equation/62)
**Author:** [@piman](https://bempp.discourse.group/u/piman)\ **Replies:** 2\ **Last updated:** [16 February 2021 11:56 UTC](https://bempp.discourse.group/t/alternative-formulation-of-maxwell-equation/62 "2021-02-16T11:56:42Z")
Hi everybody, I wonder, is it possible to apply bempp to solve Maxwell equation in alternative formulation I found in article “Overcoming Low-Frequency Breakdown of the Magnetic Field Integral Equation” https://doi.org/… --- ## [Placing monopole source at or near boundary](https://bempp.discourse.group/t/placing-monopole-source-at-or-near-boundary/47)
**Author:** [@Rasmus](https://bempp.discourse.group/u/Rasmus)\ **Replies:** 2\ **Last updated:** [30 November 2020 18:16 UTC](https://bempp.discourse.group/t/placing-monopole-source-at-or-near-boundary/47 "2020-11-30T18:16:47Z")
Hi I’m using BEMPP to solve the exterior Helmholtz problem a single point on a surface but for many incident directions. I would like to, instead of solving the linear system N times for all source position and keeping… --- ## [BEM-BEM coupling with complex wavenumber and density](https://bempp.discourse.group/t/bem-bem-coupling-with-complex-wavenumber-and-density/43)
**Author:** [@luizaugustoalvim](https://bempp.discourse.group/u/luizaugustoalvim)\ **Replies:** 8\ **Last updated:** [23 November 2020 15:58 UTC](https://bempp.discourse.group/t/bem-bem-coupling-with-complex-wavenumber-and-density/43 "2020-11-23T15:58:21Z")
Greetings everyone, To contextualize my question, I have asked on the previously used bempp group (https://groups.google.com/g/bempp/c/Tsslj2noIi4) about solving the Helmholtz transmission problem with Bempp and was ref… --- ## [Simple monopole source example gets a wrong result](https://bempp.discourse.group/t/simple-monopole-source-example-gets-a-wrong-result/41)
**Author:** [@hellojxt](https://bempp.discourse.group/u/hellojxt)\ **Replies:** 3\ **Last updated:** [22 October 2020 08:35 UTC](https://bempp.discourse.group/t/simple-monopole-source-example-gets-a-wrong-result/41 "2020-10-22T08:35:07Z")
I am learning to use bempp to solve acoustic problems. I test it with a simple monopole source example: p(x)=\\frac{e^{-i k r}}{4 \\pi r} I use the Fredholm integral equation of the first kind to calculate Dirichlet dat… [Previous page](https://bempp.discourse.group/c/applications/8.md)