Abstract

This study combined KOH anisotropic etching with laser machining to fabricate small sonic nozzles in the shape of a pyramidal convergent inlet followed by a conical diffuser with a divergent angle of 5°. The diffuser was made into three different lengths. The throat diameters were around 100 μm. Experiments were performed to obtain discharge coefficients and critical back pressure ratios in Reynolds numbers ranging from 5.8×102 to 4.5×103. The critical back pressure ratio for one of the nozzle types examined reached 0.486 at Re=4.4×103. Numerical simulations were also performed to obtain the flow fields at an upstream pressure of 203 kPa. The simulation results revealed that besides flow separation, the first set of oblique shocks appeared in the nozzle jet could also lead to tremendous pressure loss. The weaker the oblique shocks, the higher the critical back pressure ratio obtained.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.