http://www.FEA-Forums.com/ FEA Forums » Topic: comsol/capacitor simulation en Tue, 07 Feb 2012 23:15:56 +0000 http://www.FEA-Forums.com/topic/76#post-98 Fri, 20 Feb 2009 06:42:00 +0000 alienator 98@http://www.FEA-Forums.com/ <p>hi all ,</p> <p>am working with annular capacitors ,<br /> made a simulated annular plates capacitor in Comsol</p> <p>but my experimental results are not matching with the experimental results<br /> experimental capacitance's are far smaller than the simulated ones</p> <p>ex: actual capacitance for 3 mm distance is 1.4 pf<br /> by simulation we am getting around 14pf</p> <p>in Comsol i used : electrostatics module in AC/DC -3D module</p> <p>i made 2 annular plates and 2 guard rings around them , and one more big box surrounding all of them<br /> (guard rings are just 2 grounded rings surrounding both the capacitor plates , one with +ve potential other with -ve potential to reduce the effect of external disturbances on capacitance )</p> <p>in sub domain settings i have deactivated all except the big box in which i have put field and other stuff active , have put epsilon(relative) as 1 .</p> <p>now for boundary settings i gave zero charge or symmetry for the bigger box , ground for both guard rings , -1V for one plate , and set port as input for other plate ,</p> <p>when i simulate this i am getting results which are not matching with experimental values</p> <p>so somebody plzz help me out </p>