A multiblock structured grid solver for 3D Euler/Navier-Stokes equations is developed in this study. The solver employs the finite difference method together with the lower-upper scheme to provide fast solutions, while the use of multiblock structured grids allows the algorithm to be applied to complex geometries.
 The developed solver is then put to the test on a "body-only" axisymmetric model with a single-engine fighter aft-end and convergent divergent nozzles, which was previously investigated experimentally. The numerical results of the pressure distributions on the model's body obtained by the solver are compared to these experimental results. The numerical and experimental results were found to be in agreement, indicating that the solver can sufficiently solve the flow equations, and represent the physical properties of the flow.