Abstract: In this paper numerical simulations and theoreticalanalyses on complex flow with multi lateral jets interactions are presented.The NND scheme with high resolution is adopted to simulate the complexflow phenomena related to lateral jet interaction accurately and a LU-SGS implicit algorithm is usedto accelerate the converging process. A multi-block patched grid techniqueis introduced to obtain the suitable grids system, which can map the jetaccurately. The influences of the difference schemes, types of limiters,topologies of grids and flow models (laminar or turbulence) on interactionflow structures and pressure distribution are investigated, and the vortexstructures, wave structures and aerodynamic characteristic induced bylateral jet interaction are also studied. And then detailed flow simulationstudies for a typical vehicle with multi lateral jets interaction arecarried out. This highlights the complex nature of the three dimensionalinteraction phenomena and also provides insight into the physics of the flowmechanism. The influences of the jet parameters, such as the number andlocation of lateral jet, and the flow conditions, such as flight Machnumber, angle of attack, altitude on flow structures and aerodynamic forcesare analyzed. The good comparisons between the computational results and theexperimental data for the pressure distributions are obtained. It isdemonstrated that the numerical method developed in this paper can beavailable to simulate the complex flow field with multi lateral jetsinteractions and predict the aerodynamic forces in the flow.