A numerical study of the effect of the compression ratio on the biodiesel fuel spray characteristics at different blending ratios, 2020.

Abstract

In this thesis a Computational fluid dynamic study was done to study the influence of various compression ratios and various mixing ratios of biodiesel on the characteristics of the spray. A three dimensional numerical simulation was done using ANSYS-FLUENT by using internal combustion engine module. This simulation was done on a 4-stroke engine for a Ruggerini RD 270 engine. A cold flow simulation was carried for the engine with compression ratio 18 and it was validated against [31] . Another two cold flow simulations for compression ratios 17 and 16 were done upon this validation. After that a model for diesel spray was added to the cold flow engine with compression ratio 18 and it was validated against [31] by comparing the penetrating length for the two models. Upon that a models for sprays for Diesel and for various mixing ratios for Biodiesel 20% , 60% and 100 % were integrated to the three compression ratio engines 18 , 17 , and 16 respectively to study the effect of different compression ratios and the various biodiesel mixing ratios on the length of the penetrating spray of fuel and it is found that as the compression ratio increased the penetrating length decreased , the mass fraction increased the turbulent increased and the droplet size decreased which means that the high compression ratio enhance the performance of the biodiesel .