Recent content by Zoli

I couldn't solve it, so the post can be reworded.

Hi, Let us suppose we have three real matrices A, B, C and let \circ denote the Hadamard product, while AB is the conventional matrix product. Is this relation true for all A, B, C matrices: C \circ (AB) = A( C\circ B)? I looked at it more thoroughly and I realized that this assumption is...

Your code works for me. I got no error messages with MikTeX 2.9 using TeXStudio.

If I understand well, you want to make the counter smaller than the denominator. It can be done winthin an inline environment as eg. Let us see the following equation: $\frac{a}{\displaystyle a}$

I use the same math style in presentations as in articles because - in my opinion - it is much nicer.

Yes, I surmised that I changed the path of integration, since \mathrm{d}\,\varphi is negative. I forgot the idea of the potential function. Thank you.

Using this idea, I managed to perform what I wanted. Thank you!

I would like the determine the work done by gravity on a mass attached to a rod (see the attached image). The rod is assumed to be weightless and rigid. I start from the definition of work: W_{AB} = \int_{\mathbf{r}_A}^{\mathbf{r}_B} \mathbf{G}\cdot \mathrm{d}\,\mathbf{r}. In the x-y coordinate...

So if I am not mistaken I should do the following for each particle: 1. Solve the initial-value problem to gain \vec{r}(t,\vec{R}) at different time steps. For this I must solve an IVP consisting of 2 equations because of the 2D-problem. But I have \vec{v} at discrete points at each time. 2...

Dear all, I solved the Navier-Stokes equations in Eulerian description. I would like to illustrate it as follows: I thought to place particles in the domain which will characterize the fluid flow. However I must know the particle position in the Lagrangian specification. As I place the...

Thank you, now it is clear.

I do not know the finite difference approach, but I speak about the steady-state spectral or finite element solution of the problem. To prevent the checkerboard pressure distribution, one should use elements that satisfies the Babuska-Brezzi condition.

Spurious pressure values come up when we use the non-staggered approximation for the velocity and pressure. However programming spectral methods (as I deal with the spectral collocation of the Stokes-equations) is hard for staggered-grids except the case when we apply homogeneous boundary...

Hi, When we want to solve the Navier-Stokes equations coupled with the conservation of mass for incompressible fluids using the primitive-variable approach, we have to face to the problem that the equation for the continuity equation does not contain the pressure which leads to spurious...

1. Why are they linear PDEs? See http://encyclopedia2.thefreedictionary.com/Hamilton%27s+Canonical+Equations+of+Motion. I do not refer to the Hamilton-Jacobian equation: http://en.wikipedia.org/wiki/Hamilton%E2%80%93Jacobi_equation 2. So you mean that it has nice properties when we use apply...