DivergenzDüsen

DivergenzDüsen, also known as diverging nozzles or expanding nozzles, are fluid dynamic devices designed to slow down a fluid and increase its pressure. Unlike converging nozzles, which accelerate a fluid by decreasing the flow area, diverging nozzles have a cross-sectional area that increases in the direction of flow. This expansion causes the fluid's velocity to decrease, and according to Bernoulli's principle, this decrease in kinetic energy is converted into an increase in potential energy, specifically pressure.

The operation of a diverging nozzle is highly dependent on the nature of the fluid and the flow conditions. For incompressible fluids or subsonic compressible flows, the diverging section will always result in a decrease in velocity and an increase in pressure. However, for supersonic compressible flows, the behavior is different. In a supersonic flow, a diverging nozzle will actually accelerate the fluid and decrease its pressure. This counterintuitive effect occurs because the compressibility of the fluid becomes the dominant factor.

This characteristic is crucial in the design of rocket engines and jet engines. Rocket nozzles, for instance, typically have a converging-diverging shape, often referred to as a de Laval nozzle. The converging section accelerates the hot, high-pressure gas from the combustion chamber to sonic speed (Mach 1) at the narrowest point, known as the throat. The diverging section then further accelerates the gas to supersonic speeds, generating significant thrust. Understanding the principles of diverging nozzles is fundamental to optimizing the performance of various propulsion systems and other fluid handling applications where pressure recovery or controlled expansion is required.