Computational investigation of a venturi-type mixer for gaseous fuel application in a dual-fuel engine

Abstract

The combined application of biogas (BG) and producer gas (PG) in diesel engines is a challenge and has scarcely been addressed so far. The present contribution focused on designing a venturi-type mixer to regulate the flow of these gases in a diesel engine under the dual-fuel (DF) mode. The mixer is simulated using CFD software (ANSYS 15.0) with five combinations of BG-PG flow, viz. 80-20%, 60-40%, 50-50%, 40-60% and 20-80% to analyse the flow behaviour, distribution and mixing quality of these gases with the air. The results indicated significant pressure drops at the throat section, which increases the velocity and turbulence inside the mixer to achieve a homogeneous mixture of gases in the divergent section. Moreover, the study resulted in lean air–fuel mixture for all flow combinations in 1.23–1.51. The proposed mixer seem to be suitable for DF engine operation with the combined application of BG and PG.