Large-Eddy Simulation Study of Ultra-High Fuel Injection Pressure on Gasoline Sprays

Abstract

The development of gasoline spray at ultra-high injection pressures was analyzed using Large-Eddy simulation (LES). Two different nozzle hole geometries, divergent and convergent shape, were considered to inject the fuel at injection pressures ranging from 200 to 1500 bar inside a constant volume spray chamber maintained at atmospheric conditions. The discrete droplet phase was treated using a Lagrangian formulation together with the standard spray sub-models. The numerical results were calibrated by reproducing experimentally observed liquid penetration length and efforts were made to understand the influence of ultra-high injection pressures on the spray development. The calibrated model was then used to investigate the impact of ultra-high injection pressures on mean droplet size and droplet size distribution. In addition, the spray-induced large-scale eddies and entrainment rate were evaluated at different ultra-high injection pressures. Overall, simulation results showed a good agreement with available measurement data. At ultra-high injection pressures mean droplet sizes were significantly reduced and comprised very high velocities. Integral length scales of spray-induced turbulence and air entrainment rate into the spray were larger at higher injection pressure compared to lower ones. Graphic abstract

Görüntü İşleme Yöntemi̇ İle Si̇nüzoi̇dal Atalet Kuvvetleri̇ Altinda Benzi̇n Atomi̇zasyon Kali̇tesi̇ni̇n Beli̇rlenmesi̇

“…When the examination of figure 10, the droplet performance of a piezo-driven injector with 200 bar spray pressure are similar to the droplet size of ultrasonic atomization examined in this study [24]. Wadekar et al [17] conducted a numerical study and studied the change of droplet size with pressure on a jet nozzle in Fig. 11.…”

“…Over the last decade, the injection pressure of the GDI technique is increased up to 250-800 bar due to recruitment better of fuel atomization [16]. The fuel injection pressure is expected that will increase to 1000 bar by 2025, as the reduction in the size of the fuel droplets increases the surface area required for the oxygen reaction [17]. To increase the pressure a lot of costly mechanical operations are required (smaller nozzle holes, higher pressure pump technology) [18].…”

Research on Abrasive Flow Polishing Technology and Quality Control of High Performance Impeller Surface

“…Large eddy simulation can well capture the changes of ow state and the characteristics of vortex, and is applicable to the complex ow on the wall [19]. Sandip Wadekar and other scholars used large eddy simulation technology to analyze the development process of gasoline spray under ultra-high injection pressure, and conducted fuel injection test under the injection pressure of 200 to 1500 bar [20]. In order to better understand the unsteady turbulent ow inside the aspirating and oscillating blowing actuators, Jeonglae Kim and other scholars used large eddy simulation to calculate the turbulent ow inside the actuator under three inlet pressures [21].…”

Numerical Analysis of GDI Flash Boiling Sprays Using Different Fuels

“…Alternatively, they used the internal nozzle flow simulations to estimate the main variables, such as the injector hydraulic coefficients and mass flow, and fed them to the DDM model. Other authors resort to solely utilizing the DDM approach which has proved to be an accurate method in predicting the spray macroscopic and microscopic parameters [13,14]. Paredi et al [15] simulated various operating conditions of the Spray G injector and implemented a specific flash boiling evaporation model to predict liquid evaporation under superheated conditions.…”