Laser-Based Spatio-Temporal Characterisation of Port Fuel Injection (PFI) Sprays

Abstract

In the present work, detailed laser-based diagnostic experiments were conducted to characterise the spray from low pressure 2-hole and 4-hole Port Fuel Injection (PFI) injectors. The main objective of the work included obtaining quantitative information of the spatio-temporal spray structure of such low-pressure gasoline sprays. A novel approach involving a combination of techniques such as Mie scattering, Granulometry, and Laser Sheet Dropsizing (LSD) was used to study the spray structure. The droplet sizes, distributions with time, Sauter Mean Diameters (SMD), droplet velocities, cone angles and spray tip penetrations of the sprays from the injectors were determined. The spray from these injectors is found to be 'pencil like' and not dispersed as in high pressure sprays. The application of the above mentioned techniques provides two-dimensional SMD contours of the entire spray at different instants of time, with reasonable accuracy.

Planar Drop-Sizing in Dense Fuel Sprays Using Advanced Laser Diagnostic Techniques

“…It is also possible to use a single camera to record the fluorescence and elasticlight-scattering images in sequence [27,[42][43][44][45][46][47][48][49]. This approach provides reliable SMD measurements where there is reasonable confidence that the flow or spray characteristics do not change with time, steady spray [43,44].…”

“…Mie and PLIF signals were over separate injection events to obtain transient development of the ensemble averaged spray. Anand et al [42] reported time-resolved quantitative SMD distributions of PFI sprays from two-hole and fourhole plate-type injectors using the sequential imaging. In this work, calibration constant (K) was determined using granulometry with an accuracy of AE20%.…”

Modelling of mixture preparation in a small engine with port fuel injection

“…Experiments were performed on a low pressure PFI experimental facility, a schematic of which is shown in Figure 1. Only a brief description of the setup and results is presented here, as a more detailed description is available in Anand et al (2010). The setup consists of a low-pressure pump and fuel tank coupled with the PFI injector.…”

Imaging diagnostics of ethanol port fuel injection sprays for automobile engine applications

“…Many have studied important spray parameters such as the droplet diameter, spray tip penetration, and spray angle at port fuel injection (PFI) conditions [14][15][16][17][18][19][20]. For example, it is well known that increased injection pressure leads to increased turbulence levels and hence smaller droplet size [15,16].…”

“…Many have studied important spray parameters such as the droplet diameter, spray tip penetration, and spray angle at port fuel injection (PFI) conditions [14][15][16][17][18][19][20]. For example, it is well known that increased injection pressure leads to increased turbulence levels and hence smaller droplet size [15,16]. Another way to enhance the turbulence level has been to improve injector design by employing a multi-hole nozzle with a smaller hole-diameter or multi-disk orifice [16][17][18][19].…”