September 24, 2023 at 10:25 amty_jpnSubscriber
Hi,The following script was created to determine the fringe capacitance of parallel plate electrodes in MAPDL.
---------------------------------do,i,0,100,10 !変数，初値，終値，増幅度(ループの始まり)fini/cle/vie,1,1,1,1/sys,del file*.png/PREP7C*** Plate dimensions (um scale)eps0=8.854e-12 ! FREE SPACE PERMITTIVITYwidth = (100*1e-6) + (i*1e-6)height = 20*1e-6thickness = 3*1e-6separation = 10*1e-6d_dmn = 10*1e-6 ! DEPTH SURROUNDING DOMAIN EXTENDS BEYOND ELECTRODESd_inf = 5*1e-6 ! DEPTH OF INFINITE BOUNDARY ELEMENT MESHesz = 3*1e-6 ! MESH SIZEV = 0.01 ! APPLIED VOLTAGEC*** Configured for electrostatic analysis of 3D 8-node elementsET,1,SOLID123C*** Define infinite elementET,2,111,2,1C*** Material properties (relative dielectric constant in vacuum)!MP,PERX,1,8.854e-12 ! THIS IS ABSOLUTE PERMITTIVITY IN MKS, WHICH WORKS OK, BUT...MP,PERX,1,1 ! WE GENERALLY USE RELATIVE PERMITTIVITY INSTEADC*** Create your first plateBLOCK,0,width,0,height,0,-thicknesscm,electrode1_a,areaC*** Create second plateasel,noneBLOCK,0,width,0,height,separation,separation+thicknesscm,electrode2_a,areaC*** SURROUNDING DOMAINallscm,scrap1_v,volu*get,xmin,kp,,mnloc,x*get,xmax,kp,,mxloc,x*get,ymin,kp,,mnloc,y*get,ymax,kp,,mxloc,y*get,zmin,kp,,mnloc,z*get,zmax,kp,,mxloc,zvsel,nonebloc,xmin-d_dmn,xmax+d_dmn,ymin-d_dmn,ymax+d_dmn,zmin-d_dmn,zmax+d_dmncm,scrap2_v,voluallsvsbv,scrap2_v,scrap1_vC*** MESHesiz,eszvmes,allC*** ELECTRODE VOLTAGEda,electrode1_a,voltda,electrode2_a,volt,VfiniC*** SOLVE/soluallssavesolvfiniC*** POST PROCESS/post1set ! READ RESULTS INTO MADL DATABASEetab,w,sene ! BASED ON ENERGYssum*get,Wnet,ssum,,item,wC1 = 2*Wnet/(V**2)nsel,s,d,volt ! BASED ON CHARGE & VOLTAGEfsum*get,q,fsum,,item,chrgc2 = q/vC_nominal=eps0*(height*width)/separation ! NOMINAL FRINGE FREE VALUE/tla,-0.35,0.90,Capacitance (ANSYS, energy) = %C1% Fd ! ANNOTATION/tla,-0.35,0.85,Capacitance (ANSYS, Q/V) = %C2% Fd/tla,-0.35,0.80,Capacitance (nominal fringe-free) = %C_nominal% Fdalls ! CAPPED SECTION PLOTSwpro,,,90wpof,,,width/2/type,1,7/cpl,1*enddo !指定の値で終わりplns,volt/sho,png $plns,volt $/sho,close $/wait,2plve,ef,,,,vect,,on/sho,png $plve,ef,,,,vect,,on $/sho,close $/wait,2/eof----------------------------------------The capacitance of only the overlapping electrodes can be determined by a theoretical formula, but how should the capacitance be approached taking into account the electric field of the fringes?In this script, the do syntax is turned and parsed using the length of the electrode as a parameter.Best regards, and thank you.Takabayashi
September 25, 2023 at 3:33 pmBill BulatAnsys Employee
I'm sorry I don't quite understand your question. The input file creates annotated images such as the one below. The first two lines of annotation report the MAPDL-calulated capacitance including fringing deduced from results in two different ways. The third line reports the analytical fringe-free value, which is, as we expect, smaller.
Maybe I'm missing something, but I don't see how you are using loop variable "i" to vary the size or separation of the plates. Are you asking how to vary the geometry in a do loop to investigate the effect of geometry on fringing and capacitance?
Or are you asking for an analytical expression that accounts for field fringing so that you can validate the calculated value from the finite element model? You might have to search the internet for that. I don't think that this article is exactly what you want, but it might help give you an idea what kind of articles you might find if you look further:
September 25, 2023 at 8:10 pmty_jpnSubscriber
Thank you very much for reply.
The effect of the fringe electric field is simulated for each of the given capacitor dimension parameters, with the aim of deriving an approximate analytical expression. (e.g. the respective effects when looping the capacitor width in the do syntax from 0-200).
I understand about the annotations on theoretical values and fringe electric field estimation.
I want to output a list of the results when I loop through the results with the do syntax for this purpose.
Best regards, and thank you.
September 25, 2023 at 8:17 pmty_jpnSubscriber
I want to reproduce the article in the URL in MAPDL.
- You must be logged in to reply to this topic.
Boost Ansys Fluent Simulations with AWS
Computational Fluid Dynamics (CFD) helps engineers design products in which the flow of fluid components is a significant challenge. These different use cases often require large complex models to solve on a traditional workstation. Click here to join this event to learn how to leverage Ansys Fluids on the cloud, thanks to Ansys Gateway powered by AWS.
Earth Rescue – An Ansys Online Series
The climate crisis is here. But so is the human ingenuity to fight it. Earth Rescue reveals what visionary companies are doing today to engineer radical new ideas in the fight against climate change. Click here to watch the first episode.
Subscribe to the Ansys Blog to get great new content about the power of simulation delivered right to your email on a weekly basis. With content from Ansys experts, partners and customers you will learn about product development advances, thought leadership and trends and tips to better use Ansys tools. Sign up here.
- How to do the frequency response of the nonlinear vibration of a flexible PCB?
- Importing Line and Solid Bodies from SpaceClaim to Mechanical
- how to open SendCommand in Ansys
- problems facing during solution
- Still facing the same issue
- Failed to move file from solver directory to scratch directory: file.rst
- Adaptive Sizing
- Stiffness factor
- Import DAT file
- Import pressure data (coordinates and value) to ansys workbench through excel
© 2023 Copyright ANSYS, Inc. All rights reserved.