Numerical simulation of the influence of fuel temperature and injection parameters on biodiesel spray characteristics

Abstract

The purpose of this study is to investigate the effects of fuel temperature and nozzle length‐diameter ratio (L/D) on biodiesel spray characteristics, under high injection pressure and high ambient pressure, by numerical method. The analysis of spray characteristics is carried out in conjunction with the transient flow inside nozzle. To achieve this, three‐dimensional calculation grids of spray nozzle and spray domain were setup, and the needle movement was achieved by dynamic mesh technique. The reliability of spray models was validated by experimental results. It was established that the variation in spray tip penetration (STP) and Sauter mean diameter (SMD) is similar at different initial conditions. The STP increases at a faster rate initially and then slows down, whereas the SMD gradually decreases with time after the injection. In addition, a sensitivity analysis of the effects of injection parameters on biodiesel spray characteristics was conducted. Compared to the nozzle L/D, injection pressure and fuel temperature have a greater impact on biodiesel spray characteristics. The increase in injection pressure has a significant effect on the velocity distribution, STP and SMD. When the injection pressure is increased from 100 to 200 MPa, the maximum velocity of the spray core zone increases by 33.96%, the STP increases by 27.17%, and the SMD reduces by 14.81%. Furthermore, an increase in fuel temperature mainly affects the concentration distribution and the SMD of atomized droplets. When the fuel temperature is increased from 300 to 350 K, the maximum concentration of axial spray center lowers by 25.41%, and the SMD decreases by 17.19%. However, the increase of L/D chiefly impacts the concentration of axial spray center, but has little effect on other spray parameters. When the nozzle L/D is increased from 4 to 8, the maximum concentration of axial spray center increases by 20.29%.

Experimental study of spray analysis for Palmarosa biodiesel‐diesel blends in a constant volume chamber

“…33 The mixture was dissolved in the agitated flask, and the chemical reaction was continued. 34,35 The mixture was allowed in a separating funnel to segregate the glycerol layer. Finally, Palmorasa oil methyl ester was dried at 100 C. The Palmarosa oil methyl ester was blended with mineral diesel at room temperature.…”

“…Moreover, the smaller droplets are formed due to the poorer surface tension of test fuels that helps to break down the fuel droplets with ease. Mineral diesel fuel has lesser viscosity and surface tension at greater injection pressure, resulting in smaller droplets.. 35,37 4.5 | Spray area…”

Assessing fuel properties effects of 2,5-dimethylfuran on microscopic and macroscopic characteristics of oxygenated fuel/diesel blends spray

“…Density has an important relationship with weighted emission 23 . Because droplet lifetime hinges on the activity coefficient in heating and evaporation, the evaporation characteristics of fuel have a certain influence on the combustion process [24][25][26] . Latent heating reduces soot emissions via longer liquid penetration 27 .…”

Effect of Low ALR on the Spray Characteristics of a Pressure-swirl Duplex Nozzle

“…This affects the hydraulic behavior of the nozzle, namely the volumetric flow rate. Atomization characteristics are dependent on atomizers geometry, injection condition, and fuel physical properties (Vashahi and Lee 2018;Dafsari, Lee, et al 2019a;Dafsari et al 2017;Geng et al 2020). The main drawback of the simplex pressureswirl nozzle is that the turn-down ratio of the liquid flow is not enough to provide efficient combustion (Chen et al 1990).…”