A three-dimensional Euler flow analysis code for Fan-Jet Engine and Turbine Powered Simulator(T.P.S) wind tunnel testing was developed utilizing MacCormack's scheme in the finite volume form for the purpose of confirming the validity of the T.P.S testing method in the NAL2×2m Transonic Wind Tunnel. The present analysis is made for the preliminary single axisymmetric T.P.S configuration. The wind tunnel experimental data for this model was available. The result of the numerical computation was compared with this data. The pressure distributions on the inlet cowl surface and core-jet cowl surface showed excellent agreement between the experiment and the computation. Different engine conditions between the real fan-jet engine and T.P.S. simulation, i.e. difference of core-jet exhaust temperature and difference of mass flux relations, were analysed, simulating respective engine conditions. The result shows that the two flows do not differ much qualitatively in the external flow field surrounding the exhaust jet plume. This comes from the fact that the use of the Euler code and the coarse mesh precluded obtaining a result amenable to quantitative discussion including the effects of viscosity and the turbulence/shock wave interactions in the plume field. Nevertheless the present result shows that the T.P.S. testing method is a good full-configuration aerodynamic testing method for fan-jet engines. To extend the method, three-dimensional flow analysis was made and it revealed the angle of attack effects in the inlet flow field, such as the flow uniformity at the fan face and in the jet exhaust plume including the formation of a pair of longitudinal vortices in the shear layer between the jet plume and the external flow. The computation and the discussion of the details of such flow fields with vortices are left for future work.