The individual effects of cetane number, oxygen content or fuel properties on performance efficiency, exhaust smoke and emissions of a turbocharged CRDI diesel engine – Part 2

•Diesel-HRD fuel blends involving ethanol (E) or biodiesel (B) were investigated in a turbocharged CRDI engine.•Bsfc was 0.9–1.3% lower when using fuel blends involving ethanol or biodiesel with CN=67.3 at λ=1.20 and 2500rpm.•The NOx increased by 15.8% (E) or 2.7% (B) with enhanced CN rating and more with ethanol-oxygen at all speeds.•The NOx emissions increased by 10.6% or 5.0% when using oxygenated blends OE2 or OB5 at λ=1.20 and speed of 2500rpm.•Smoke, CO, and THC emissions decreased with the most oxygenated fuels OE5 or OB5 at λ=1.20 and speed of 2500rpm. The paper presents the individual effects made by the variation of cetane number, fuel-oxygen content, or widely differing properties of diesel-HRD fuel blends involving ethanol (E) or biodiesel (B) on the performance efficiency, brake specific fuel consumption, exhaust smoke and NOx, CO, HC emissions of a turbocharged CRDI diesel engine. The dominant factors one after another operated separately to reveal their contribution to changes in operational parameters. Load characteristics were taken with a straight diesel and various (18 in total) fuel blends at maximum torque mode of 2000rpm and additional speeds of 1500 and 2500rpm to improve interpretation of the test results. The (bmep) characteristics were plotted as a function of relative air-fuel ratio (λ) to analyse performance and engine out emissions for relative ‘lambda’ values of=1.30, 1.25 and 1.20, at the respective speeds of 1500, 2000 and 2500rpm. Parameters obtained when using fuel blends of both E and B origins were compared with those measured with ‘base-line’ blends possessing normal CN rating or zero content of oxygen and a straight diesel to reveal the resulting development trends. The combustion characteristics (Part 1) were used to properly interpret the resulting changes in engine performance and emissions. The brake thermal efficiency equally increased by 0.5%, NOx emissions by 15.8% or 2.7%, smoke and CO decreased 1.7 times or by 34.9% and 7.2 times or increased by 18.8% when running with the most flammable (CN=67.3) fuel blends E or B at λ=1.20 and the high speed of 2500rpm. The engine efficiency increased by 2.9% or 0.5%, NOx emissions by 10.6% (1.81wt%) or 5.0%, smoke and CO emissions decreased 3.0 times or by 46.7% and by 63.3% (3.61wt%) or 49.5% when using the most oxygenated (4.52wt%) fuel blends series E or B under given test conditions.