Effects of Heavy Fuel Oil Blend with Ethanol, n-Butanol or Methanol Bioalcohols on the Spray Characteristics

Abstract

Blending of fossil fuels with alcohols is one of the most impressive strategies for emission control and enhancement of fuel efficiency. Accordingly, in the current paper, the effects of blend of Heavy Fuel Oil (HFO) with bioalcohols are numerically studied on the non-reacting spray characteristics. Three different fuels are considered by mixture of HFO with 20% of n-Butanol, Ethanol, and Methanol and compared against Pure HFO. For this purpose, the microscopic and macroscopic spray characteristics of the blended fuels are evaluated through the investigation of spray penetration, cone angle, spray volume, and Sauter Mean Diameter (SMD). Moreover, for detailed understanding of the spray characteristics, the non-dimensional numbers of Weber and Ohnesorge, and liquid spray morphology are analyzed. Also, the study of Histogram of density and droplet diameter is conducted. Eulerian-Lagrangian multiphase scheme is used for simulation of air-fuel interaction in OpenFOAM CFD toolbox. Lagrangian Particle Tracking method is utilized for fuel droplet tracking in Lagrangian scheme. A hybrid breakup model of KH-RT and standard model of k-ε in RANS is used respectively for breakup and turbulence modeling. The obtained numerical results are validated against existing experimental data with suitable accordance. Based on the computational results, longer spray penetration length, larger spray cone angle and greater spray volume are achieved for the blended fuels. It was also concluded that HFO-Ethanol improves the macroscopic characteristics compared to two other blended fuels, albeit the effect is very minimal. In addition, lower SMD value is obtained for the blended fuels compared to pure HFO.