[hadiso]

Hi every one,
I'm solving a shock tube problem using a Roe scheme (structured grids) which works fine on first order accuracy. I want to improve the solution to higher order starting from second order.
I simply extrapolate the solution from the cell centers to faces using the gradients:

Uface=Ucenter+Grad_U*r

where r is the distance between the face and center. using this second order Taylor series I manage to improve the solution in the expansion region but the shock capturing is exactly the same as the first order solution. I use a MidMode slope limiter for the second order solution. I can's see where the problem is.
any experiences?