17 edited tags | link edited Oct 13 '18 at 6:42 J. M. is away♦ 100k1010 gold badges316316 silver badges473473 bronze badges 16 added 96 characters in body edited Jan 24 '18 at 11:14 chris 12.7k44 gold badges4545 silver badges121121 bronze badges I would like to compute the torque that a  (thin) disc applies onto a ring. I.e. I would like to try to understand what is the impact of this outer ring on the inner disc in the simulation below. For this I would like to compute the gravitational potentiapotentiall generated by a (razor) thin disc and a ring. So the abstraction is the following (seen from 9 different angles) Once I know how to compute the potential it becomesshould become straightforward to compute the torque one feature applies on the other. IHere I want to use FEM here for flexibility, which I will use when I will account for a more realistic abstraction of the problem. (e.g. exponential surface density profile in disc). I would like to compute the torque that a  (thin) disc applies onto a ring. I.e. I try to understand what is the impact of this outer ring on the inner disc in the simulation below. For this I would like to compute the gravitational potential generated by a (razor) thin disc and a ring. So the abstraction is the following (seen from 9 different angles) Once I know how to compute the potential it becomes straightforward to compute the torque one feature applies on the other. I want to use FEM here for flexibility when I will account for a more realistic abstraction of the problem. I would like to compute the torque that a (thin) disc applies onto a ring. I.e. I would like to try to understand what is the impact of this outer ring on the inner disc in the simulation below. For this I would like to compute the gravitational potential generated by a (razor) thin disc and a ring. So the abstraction is the following (seen from 9 different angles) Once I know how to compute the potential it should become straightforward to compute the torque one feature applies on the other. Here I want to use FEM here for flexibility, which I will use when I will account for a more realistic abstraction of the problem. (e.g. exponential surface density profile in disc). 15 deleted 1 character in body edited Jan 21 '18 at 10:33 chris 12.7k44 gold badges4545 silver badges121121 bronze badges edge = {DirichletCondition[u[x, y] == 1, 0 <= x <= 1/2 && y == 0};0]; StreamPlot[-{D[#, x], D[#, y]} &@uD[x, y] // Evaluate, {x, y} \[Element] dom]dom,AspectRatio->2]  edge = {DirichletCondition[u[x, y] == 1, 0 <= x <= 1/2 && y == 0}; StreamPlot[-{D[#, x], D[#, y]} &@uD[x, y] // Evaluate, {x, y} \[Element] dom]  edge = DirichletCondition[u[x, y] == 1, 0 <= x <= 1/2 && y == 0]; StreamPlot[-{D[#, x], D[#, y]} &@uD[x, y] // Evaluate, {x, y} \[Element] dom,AspectRatio->2]  14 added 127 characters in body edited Jan 21 '18 at 8:22 chris 12.7k44 gold badges4545 silver badges121121 bronze badges 13 suggestion edited Jan 21 '18 at 7:50 chris 12.7k44 gold badges4545 silver badges121121 bronze badges Tweeted twitter.com/StackMma/status/954803461991919616 occurred Jan 20 '18 at 19:50 12 deleted 54 characters in body edited Jan 20 '18 at 18:47 chris 12.7k44 gold badges4545 silver badges121121 bronze badges 11 deleted 54 characters in body edited Jan 20 '18 at 18:41 chris 12.7k44 gold badges4545 silver badges121121 bronze badges 10 added 104 characters in body edited Jan 20 '18 at 18:13 chris 12.7k44 gold badges4545 silver badges121121 bronze badges 9 added 104 characters in body edited Jan 20 '18 at 18:08 chris 12.7k44 gold badges4545 silver badges121121 bronze badges 8 added 115 characters in body; added 1 character in body edited Jan 20 '18 at 17:10 chris 12.7k44 gold badges4545 silver badges121121 bronze badges 7 added 3 characters in body edited Jan 20 '18 at 17:00 chris 12.7k44 gold badges4545 silver badges121121 bronze badges 6 deleted 3 characters in body; edited title edited Jan 20 '18 at 16:47 chris 12.7k44 gold badges4545 silver badges121121 bronze badges 5 added 161 characters in body edited Jan 20 '18 at 16:34 chris 12.7k44 gold badges4545 silver badges121121 bronze badges 4 edited title edited Jan 20 '18 at 16:23 chris 12.7k44 gold badges4545 silver badges121121 bronze badges 3 edited title | link edited Jan 20 '18 at 16:21 chris 12.7k44 gold badges4545 silver badges121121 bronze badges 2 added 51 characters in body edited Jan 20 '18 at 16:00 chris 12.7k44 gold badges4545 silver badges121121 bronze badges 1 asked Jan 20 '18 at 15:51 chris 12.7k44 gold badges4545 silver badges121121 bronze badges