Numerical and Experimental Spray Analysis of Castor and Jatropha Biodiesel under Non-Evaporating Conditions

Abstract

Fuel spray characteristics influence combustion, which in turn has a direct impact on engine performance and emissions. Recently, there has been an increasing interest in novel castor oil biodiesel. However, few investigations have been performed that combine both numerical and experimental biodiesel spray analyses. Hence, in this paper, we aim to explore the spray behavior of castor and jatropha biodiesel by employing numerical and experimental methods under non-evaporating, varying injection, and ambient conditions. The experimental study was carried out in a control volume vessel (CVV) at high injection and ambient pressures. The fuel atomization was modelled in ANSYS Fluent using a Lagrangian/Eulerian multiphase formulation. The results revealed that the Kelvin–Helmholtz and Rayleigh–Taylor (KHRT) model coupled with the Taylor Analogy Breakup (TAB) model provide a better estimation of the penetration length (PL) and spray cone angle (SCA) compared to the KH and TAB models. On average, Jatropha biodiesel (JB-20) and castor biodiesel (CB-20) showed a 10% to 22% longer PL, 8% to 10.6% narrower spray cone angles, and 3% to 6% less spray area, respectively, compared to diesel. The numerical predictions showed that JB-20 and CB-20 had an around 24.7–48.3% larger Sauter mean diameter (SMD) and a 38.6–73.3% average mean diameter (AMD).

Performance and Emission Characteristics of Second-Generation Biodiesel with Oxygenated Additives

“…On the other hand, when Jatropha biodiesel was blended with lower-chain alcohols such as ethanol, butanol and pentanol, it showed an increase in BSFC compared to the biodiesel blend (without oxygenated additives) and diesel [120,122]. This increased BSFC might be caused due to the poor atomization quality of Jatropha in contrast to diesel [140]. Calophyllum inophyllum biodiesel and rubber-seed biodiesel, when blended with lower-chain alcohols, i.e., 40% 1-Pentanol and 20% Butanol, showed the highest BSFC as compared to the biodiesel blend (without oxygenated additive) and diesel [106,133].…”

“…Therefore, to gain benefits in terms of NOx, it is suggested to blend oxygenated additive with biodiesel which can have a moderate oxygen content and cetane number to obtain an optimized engine performance in addition to better emission characteristics. [108][109][110][111][112][113][115][116][117][118][119][120]122,124,128,129,134,135,[137][138][139][140][141][142][143][144].…”

“…The impact of several oxygenated additive-based second-generation biodiesel blends on the performance and emissions of a diesel engine was investigated in this review article. In comparison to conventional diesel, changes in brake-specific fuel consumption and brake thermal efficiency, as well as changes in emissions such as carbon monoxide, carbon [108][109][110][111][112][113][115][116][117][118][119][120]122,124,128,129,134,135,[137][138][139][140][141][142][143][144].…”

“…Figure 2. Trends of brake-specific fuel consumption from the literature[108][109][110][111][112][113][114][115][116][117][118]120,122,124,125,128,132,133,135,138,140].…”