AMRFLEX3D -- flow simulation using a three-dimensional self-adaptive, structured multi-block grid system We describe a numerical procedure for integration of structured grid blocks. Such blocks are the basic elements of the self-adaptive grid structure. A hierarchically ordered level system, which reflects different refinement stages, serves as a scaffold. After a description of sensors used for refining interesting flow phenomena, an overview about the integration steps is given. The application of AMRFLEX3D to the case of a three-dimensional, inviscid, supersonic corner flow and of a delta wing under transonic flow conditions is presented. For the latter simulation, both Euler and Navier-Stokes equations are used. Conclusions that can be drawn from experiences with grid refinement are given.