Open AccessEffect of Ribs as Passive Control on Base Pressure at Sonic Mach Numbers
Author(s) -
Aijaz Ahmed Khan,
Nurul Musfirah Mazlan,
Erwin Sulaeman
Publication year - 2022
Publication title -
cfd letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.288
H-Index - 13
ISSN - 2811-3969
DOI - 10.37934/cfdl.14.1.140151
Subject(s) - mach number , nozzle , duct (anatomy) , mechanics , rib cage , materials science , pressure drop , base (topology) , flow (mathematics) , static pressure , structural engineering , acoustics , engineering , physics , mathematics , aerospace engineering , anatomy , medicine , mathematical analysis
Passive control is a method used to control the base pressure of the convergent-divergent nozzle for high speed vehicles. The passive control contributes significant reduction of base pressure which mainly depending on many factors such as number of ribs, flow Mach number and rib’s size. The flow behaviour inside the nozzle at the respected factors still unknown. Therefore, this study aims to assess the effect of ribs in a suddenly expanded flow to control the base pressure at sonic Mach numbers. The study is performed using ANSYS Fluent. The flow expands in a duct with 18 mm diameter and 108 mm length. The ribs have aspect ratios of 3:1 to 3:3 which were fixed to the duct circumferentially. The position of the rib varies from 1D (duct diameter) to 4D and having different aspect ratios. The level of expansion varies from 1.5 to 5 while the rib is fixed at a 3:3 aspect ratio. The variation of pressure and velocity contours of the flow inside the nozzle are presented. The simulation analysis indicates that the flow expansion with the presence of ribs considerably improves the base pressure. It is concluded that at the flow with sonic Mach number, the rib with a 3:3 aspect ratio located at 4D has shown the highest improvement in base pressure.