The flow field of single and twin-jet impingement was investigated using FLUENT. A single jet design having an inlet diameter of 2 m and an outlet diameter of 1 m was used with the boundary conditions given in such a way that the ratio of exit pressure to the ambient pressure was 1.41 thus creating a moderately under-expanded jet. The design and modeling were validated using shock length calculations and grid independency test. The twin jet impingement study was done by varying various design parameters such as the nozzle distance, deflector distance, deflector angle and the nozzle angle. In all the cases, the pressure and velocity distribution over the deflector was studied which gives an approximate magnitude of the fountain flow and the entrainment caused due to the flows moving in opposite direction.