Abstract : Nozzles are widely used in propulsion system. This paper presents a brief study on effect of spike geometry on Nozzle performance using Numerical techniques. Four geometry concepts are simulated for studying the effect of spike angle and truncation on the performance of spiked nozzle. One reference case is taken as base for comparison and results are discussed for other remaining cases. Grid independency study is made, system of fluid flow equations is solved using Ansys software. Mach contour plots, thrust force graphs, and velocity graphs are presented and discussed. © 2019 Author(s).