Time Space dependent Interpolation function

Hello!
I want to use a velocity boundary solution u(x, t) from one physics in another physics. The timesteps, the mesh and the geometry are equal. I use the Laminar Two Phase Flow, level Set physics in COMSOL 4.3. I have red a lot of post, but I couldn't find a solution. Especially in 4.3. I followed two approaches:

1. I tried to use the dependent variable u from solution 1. With the solver notes I just can transmit one step from solution 1 to the initial conditions of solver 2. But I want the whole velocity over time used for computing.

2. I exported the solution 1 on the boundary as a 1D Line Graph at all times. Then I changed the exported txt file to the standard COMSOL spreadsheet column1=x column2=t and column3=u(x, t) It looks like:
0 0 0.34
0.2 0 0.16
0.3 0 0.31
0 0.1 0.28
0.2 0.1 0.19
0.3 0.1 0.23
0 0.2 0.29 and so on.
Then I imported it in the definitions (I tried global and local) note as a interpolation function int1 (x, y). When I call the function in the physic via u(x, t) no errors occur. But in the results I can see that that the function doesn't transmit time-dependent values.
Thanks for any help!