Air demand prediction and air duct design optimization method for spillway tunnel. Issue 3 (4th May 2021)

• Record Type: Journal Article
• Authors: Lian, Jijian; Wang, Xiaoqun; Liu, Dongming
• Is Part Of: Journal of hydraulic research. Volume 59:Issue 3(2021)
• Page Start: 448
• Page End: 461
• Publication Date: 2021-05-04
• Subjects: Air demand -- air–water stratified flow -- design optimization -- interfacial shear stress -- negative pressure -- spillway tunnel; Hydraulics -- Research -- Periodicals; Hydraulic engineering -- Periodicals; Hydraulic engineering; Electronic journals; Periodicals; 621.2
• DOI: 10.1080/00221686.2020.1780499
• Languages: English
• ISSNs: 0022-1686

Abstract

ABSTRACT: Accurate calculation of air demand is fundamental in the design of air ducts in a spillway tunnel. However, it was often underestimated by empirical formulas in previous studies. In this paper, an air–water stratified flow model, in which the air and water are coupled by a new interfacial shear stress formulation, is proposed. The model is verified by using prototype data and numerical CFD results and proved to give better prediction of air demand for the spillway tunnel of the Jinping-I hydraulic project in China. In order to reduce the unfavourable high velocity of air in the air ducts, the model is also applied to optimize the design of air ducts of the Jinping-I project. We conclude that the model proposed in this paper can give more accurate results than the previous empirical formulas for air demand and is more convenient than 3D numerical models for engineering designers.