Randi Purnama Putra, Sutardi, Wawan Aries Widodo
Airduct system is not only a straight pipe, but there are also piping fittings/accessories such as 90°elbows. These pipe accessories work so air ducts can be installed as needed. However, the use of these piping accessories causes an increase in pressure drop due to friction loss, separation loss and secondary flow that occurs after the flow passes through the fittings. There is a considerable pressure drop on the ducting system, then the fluid flow will suffer a considerable energy loss as well. A method to reduce the pressure drop that occurs in the 90°elbow is by adding an inlet disturbance body (IDB). This study was conducted numerically and experimentally on a square duct with hydraulic diameter Dh = 125 mm and curvature ratio R/Dh = 1.5. Inlet disturbance body (IDB) is placed at the inner upstream side of the duct before the 90°inlet elbow with variation on distance l/Dh = 0.1 - 0.5, constant gap g/d = 0.2 and d/Dh = 0.1. Reynolds number (ReDh) is 3.97 × 104 < ReDh < 13.5 × 104. The turbulence model is k-ϵ realizable. From this research it can be obtained information that the use of IDB effectively recovers flows process and overcomes the negative effect of the secondary flow. IDB placement of the channel with distance l/Dh = 0.1 is the most effective distance to reduce pressure drop with decrease of 17.68%. While IDB with distance variation l/Dh = 0.5 has the highest pressure drop. © 2018 Author(s).
Department of Mechanical Engineering, Faculty of Industrial Technology, Institut Teknologi Sepuluh Nopember, Surabaya, 60111, Indonesia; Department of Automotive Engineering, Faculty of Engineering, Universitas Negeri Padang, Padang, 25171, Indonesia
