Grooved cavity as a passive controller behind backward facing step

• Main Authors: Khan, Sher Afghan, Alrobaian, Abdul Rahman, Asad Ullah, Mohammed, Khan, Abdul Mohsin
• Format: Article
• Language: English; English
• Published: Penerbit Akademia Baru 2019
• Subjects: TL1 Motor vehicles
• Online Access: http://irep.iium.edu.my/69634/7/69634%20Grooved%20Cavity%20as%20a%20Passive%20Controller.pdf; http://irep.iium.edu.my/69634/8/69634%20Grooved%20Cavity%20as%20a%20Passive%20Controller%20%20SCOPUS.pdf; http://irep.iium.edu.my/69634/; http://www.akademiabaru.com/doc/ARFMTSV53_N2_P185_193.pdf
• Institution: Universiti Islam Antarabangsa Malaysia

A semicircular grooved cavity is designed for controlling the base pressure and hence the base drag in case of a backward facing step. This paper presents the effect of the continuous grooved cavity to control the base pressure for various compressible subsonic flow to minimize the base drag. The grooved cavity of 1.5 mm radius at 45o along a pitch circle diameter of 23 mm in the base region is employed as a passive controller. The test is conducted for Mach 0.6, 0.7, 0.8 and 0.9. The square nozzle of side 10 mm with an angle of incidence as 150 on all four sides from which the flow suddenly expands to a square duct of side 25 mm acts as backward facing step model. The experimental investigation is carried out for three ducts of length equivalent to 4, 6 and 8 times width. The results of this investigation provide grooved cavity at 45o as a very effective passive control mechanism to regulate the base flows, further at higher Mach numbers it may be associated with the minor effect on the main flow field.