Recent content by CIMP

Dear All, Thanks a lot to everybody for the advices. I learn a lot in this forum always... Yes! I see that this is a Ricatti equation and I think the best is to solve it with numerical methods... asssuming the initial conditions for each one the variables depending on "t". Thanks again...

Thanks a lot Mark44 and LCKurtz. C is also function of time. In that case, if there is not hope for explicit solution, should I try to solve it numerically? and if yes? which method could I use? I know how varies A, B and C as a function of another variable "Z". In other words: dV/dt=...

Dear all, Someone could help me to understand how I can resolve the following equation : dV/dt= A V^2 + B V + C Where V :V(t), A(t), B(t), C(t) Is there any method or indications about this ? Thanks in advance, Indira

Yes! :smile: Thanks! "Mathematics is the language of nature..."

Hello Mentallic, Thank you very much for your help. I really could advance more with your explanation. I made a plot as suggested by Jamma, and I could see that the function when X<5 it tend to -infinit and if X>5 it also tends to +infinit. Hello Jama, Thank you very much for your...

Mentallic, Thanks a lot for your reply. I mean, I want to know the value of "X" when "Y=5". Thanks in advance,

Hello All, Could you please indicate me how to resolve this equation: ln(y) (x^4 - y^4)+ ln(x) (y^4 - x^4) + (y^2 - x^2)^2 = 0 I am really struggling with it... Thanks in advance, C:)

I think that for the gradient of U, I should put each term of the matrix without sum as follows (I don't know how to put in LateX the brackets to the matrix): Grad(U) = [d/dx1 U1 d/dx2 U1 d/dx3 U1 d/dx1 U2 d/dx2 U2 d/dx3 U2 d/dx1 U3 d/dx2 U3 d/dx3 U3] I guess this part is Ok...

Dear Arildno, Thanks a lot for your reply. Is the following fine: Grad (u)= [d/dx1 U1 + d/dx2 U1 + d/dx3 U1 d/dx1 U2 + d/dx2 U2 + d/dx3 U2 d/dx1 U3 + d/dx2 U3 + d/dx3 U3] After this step, I need to calculate the magnitude and finally to multiply...

Thanks a lot for your reply. If I understood well, then the gradient of the velocity vector is going to be: Be V the velocity vector V=(Ux,Vy,Wz) Grad (V) = (d/dx Ux + d/dx Uy + d/dx Uz d/dy Ux + d/dy Uy + d/dy Uz d/dz Ux + d/dz Uy + d/dz Uz)...

Dear all, Someone could help me to understand how is mathermatically expressed the amplitude of the velocity gradient? For example if vector of velocity is V(Ux,Vy,Wz) The amplitude of the velocity gradient is? : grad(V)= d/dx(Ux) +d/dy(Uy) + d/dz(Uz) Is it fine? Thanks in...