The impact of inlet mach number and domain shape on subsonic nozzle flow via small disturbance equation

Abstract

Computational fluid dynamics (CFD) is a cross-disciplinary field that combines mathematics, fluid dynamics, and computer programming to simulate and analyze fluid flow problems using numerical methods. Nowadays, the use of CFD to conduct numerical simulations rather than costly and time-consuming ignition experiments has become an essential aspect of nozzle design. Therefore, it is significant to study the nozzle by numerical simulation. In this paper, a numerical method called small disturbance equation (SDE) is adopted to investigate the impact of inlet Mach number and domain shape on subsonic nozzle flow. Conducting the small disturbance equation via python code, the impact of the inlet Mach number and domain shape is revealed by comparing the different errors of the method, streamlines of the nozzle flow, velocity fields. It is found that with the increase of inlet Mach number, the error of the SDE method grows, and the velocity in x-direction increases while the velocity in y-direction stays the same. Besides, with the shrink of the domain shape, the error of the SDE method gets larger, meanwhile, the maximum of the velocity in each direction increases while the minimum of the velocity decreases. This research would make advantages to identify the optimal designs of a subsonic nozzle.