The current landscape of the New Space Economy dictates the development of cutting-edge propulsion technologies capable of combining high technical performance with a significant reduction in operational costs. Precisely from these stimuli arises the need to investigate in detail the physics governing the pintle injector. This technology is currently the subject of intense study precisely as a function of cost reduction, as it is perfectly suited for next-generation, fully reusable launchers, which require a wide thrust range to utilize the same engines for both the energetic ascent phase and the delicate landing maneuvers. Among the peculiarities of the pintle, the ability to operate with variable geometry stands out, allowing for thrust modulation (throttling) without drastically affecting the complexity of the feed system.