You have already tried our free simulation software QuickField Student Edition, but your problem requires more dense finite element mesh?.
Order the Professional Edition - and you will easily deal with meshes of several hundreds of thousands nodes. Of course you'd prefer to try it of no cost before buying. If you need to get full impression of QuickField capabilities prior to making a purchasing decision - you are welcome to request a free evaluation of QuickField Lite or Professional Editions.
Or, if you are not currently planning to purchase the Professional Edition, but still interested to check it - there is a simple way of doing it. You may describe the problem by QuickField Student Edition editors, and then send us the problem files. We will make more dense mesh and re-solve it by the Professional Edition, and then send you the results back. Freeware postprocessor can load the solution and you will be able to postprocess results by yourself.