Study of Three-Dimensional Wall Effects on Micro Nozzle’s Performance

Abstract

According to the lever moment equilibrium, the thrust test is performed for a flat micro convergent-divergent micro nozzle with 11.72 geometry expansion ratios. During the test process, since the distances between the Piezoelectric sensors point and the bearing point are much larger than the distance between the nozzle and the bearing point, thus the thrust signal is amplified. Compared with the test results, the FLUENT6.1 software is also applied to compute steady two-dimensional and three-dimensional Navier-stokes equations for numerical results by parallel computing. The numerical results and test results show that： for the flat micro nozzle with small ratio of throat depth and width, three-dimensional wall effects are not negligible. Three-dimensional numerical results agree well with the test results while there are large differences between two-dimensional numerical results and test results. With the throat Renaults being increased, the corresponding differences between two-dimensional numerical results and test results decreased accordingly