To sustain the arc in the arcjet, the swirl is thought to be necessary. This paper conducts a numerical study on various geometry and input conditions. The effect of swirl and wall temperature of a nozzle on the plasma flow, arc behavior, and performance parameter of low power arcjet has been studied. The physics behind the working of low power arcjet and behavior of swirl velocity has been plotted. Various aspect of swirl, which stabilizes the arc, is also discussed.