Passive control of base pressure in a converging-diverging nozzle with area ratio 2.56 at mach 1.8

• Main Authors: Husnina, Nur, Khan, Sher Afghan, Aabid, Abdul, Baig, Muneer, Shaiq, Istiyaq Mudassir
• Format: Article
• Language: English; English; English
• Published: Tech Science Press 2023
• Subjects: TL Motor vehicles. Aeronautics. Astronautics; TL780 Rockets
• Online Access: http://irep.iium.edu.my/100351/7/100351_Passive%20control%20of%20base%20pressure.pdf; http://irep.iium.edu.my/100351/13/100351_Passive%20Control%20of%20Base%20Pressure%20in%20a%20Converging-Diverging%20Nozzle%20with%20Area%20Ratio%202.56%20at%20Mach%201.8%20_%20SCOPUS.pdf; http://irep.iium.edu.my/100351/14/100351_Passive%20Control%20of%20Base%20Pressure%20in%20a%20Converging-Diverging%20Nozzle%20with%20Area%20Ratio%202.56%20at%20Mach%201.8%20_WOS.pdf; http://irep.iium.edu.my/100351/; https://www.techscience.com/fdmp/v19n3/50053/pdf

In this study, a duct is considered and special attention is paid to a passive method for the control of the base pressure relying on the use of a cavity with a variable aspect ratio. The Mach number considered is 1.8, and the area ratio of the duct is 2.56. In particular, two cavities are examined, their sizes being 3:3 and 6:3. The used L/D spans the interval 1–10 while the NPRs (nozzle pressure ratio) range from 2 to 9. The results show that the control becomes effective once the nozzles are correctly expanded or under-expanded. The pressure contours at different NPR and L/D are presented. It is shown that the NPR and cavity location strongly influence the base pressure. The NPR, Mach number, and cavity aspect ratio have a strong effect on the base pressure in the wake region.