Computational analysis of mixing characteristics of port-injected bioCNG with air for different designs of intake manifold

Abstract

The bioCNG with 90% of methane makes a potential renewable alternative of CNG for the application in dual-fuel diesel engine. The bioCNG is to be inducted in the manifold through port injection. The work is aimed to find the optimum port length and port-injector diameter. The objective is to mix bioCNG homogenously with air, before entering the engine. This would create an opportunity for major replacement of diesel to reduce the running cost of the vehicle. The two injector diameters (7 mm and 10 mm) and four port lengths (0 mm, 100 mm, 150 mm and 200 mm) are investigated. The manifold has a diameter of 28.5 mm and the port-injector is inclined at 35° to the manifold axis. The geometries are simulated in ANSYS Workbench 19.2, and post-processed in Tecplot. The results show that the port length of 200 mm with an injector diameter of 7 mm delivered homogeneous mixture in dual-fuel mode.