The study of transient high pressure fuel sprays by X-ray based techniques is worldwide diffused. Synchrotron radiation is successfully exploited for this aim because of its high intensity and pulsed nature. However top-table application are unusual. This work reports the structure of a gasoline spray from an automotive GDI injection system obtained by X-ray Tomography desktop experiments using an 8 keV Cu Kα X-ray. Polycapillary semilens shaped the divergent X-ray beam into quasi-parallel one allowing to focus the radiation on the investigated spray region. High contrast focus images were collected by a CCD detector for X-radiation. A 6-hole GDI injector has been coupled to the high pressure pump by a specially designed rotating device able to work up to 25MPa. X-ray absorption measurements have been performed with angular steps Δθ = 1° at the injection pressure of 12.0 MPa. The sinogram reconstruction of the jets by slices permitted to get information about the inner structure of the fuel spray downstream the nozzle tip, where conventional optical techniques are inhibited. A 3D spatial distribution of the fuel emerging from the injector has been obtained. The data have been used to perform spray density measurements. The results concerning the absorption profile along the fuel jets axis and the cross section distribution at different distances from the nozzle have been reported.
Thin films of permanent magnetic material are very important for different electronics applications. Permanent
magnetic films are used also for micromechanical systems and for microwave integrate circuits. We present preliminary
results on SmCo thin films grown on commercial plastic substrates. X-Ray Fluorescence and Magnetic Scanning
measurements using GMR (Giant Magnetoresistive) sensors have been performed with the aim to study the functional
magnetic properties of the thin film.
Thin film of permanent magnetic material is very important for different electronics application1,2
We present here preliminary results on SmCo thin film grown on steel substrate. X-Ray diffraction data Magnetic
Scanning SQUID (Superconducting Quantum Interference Device) and Vibrating Sample Magnetometer (VSM)
analyses have been performed with the aim to study the functional magnetic properties of the deposited thin film.
In this paper UV-visible elastic light scattering and Planar Laser Induced Fluorescence (PLIF) have been applied for measuring the vaporization process of a diesel fuel in an optically accessible vessel at engine ambient conditions. The spray has been generated by an electronically controlled Common Rail injection system and emerged from an axial single-hole electroinjector, 0.18 mm in diameter (L/d = 5.55). The injected fluid has been a commercial Diesel fuel and a
single strategy (1.0 ms in duration) has been implemented at the injection pressure of 60.0 MPa. The measurements have been carried out in a quiescent bomb filled with SF6 gas at pressures of 0.39 MPa and temperature ranging between 293 to 533 K. The ambient gas densities has varied from 12.64 kg/m3 to 23.0 kg/m3, equivalent to the diesel engine conditions between the Start of Injection (SOI) and the Start of Combustion (SOC).
A Nd-YAG pulsed laser sheet has been used for excitation of the spray along its axis at two wavelengths: 532 and 355 nm; the sheet thickness and light pulse duration have been 0.10 mm and 12 ns, respectively. The scattered light has been collected and synchronized at different instant from the SOI. The comparison of the images of the fuel at different instant from the SOI has permitted the analysis of the spray characteristics in terms of tip penetration, cone angle and spray fragmentation. Elastic visible and UV scattering radiation
have allowed investigations on the size of the droplets along a plane centered on the spray axis. Planar Laser Induced Fluorescence (PLIF) measurements on the same plane have been carried out exciting the droplets at 355 nm and collecting the light through an interference filter centered at 430 nm. PLIF has allowed a correlation between the liquid and the vapor structures of the jets in all the examined ambient conditions.