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An experimental and numerical study of GDI sprays from a Common Rail injection system has been performed. A non-evaporative gasoline-like fuel has been injected into a high-pressure test chamber, at room temperature and quiescent gaseous environment, from a single hole VCO high pressure electronic controlled injector. Sprays have been lightened by a pulsed laser sheet from a Nd-YAG at 532 nm (100 micro m thickness and 12 ns duration) and acquired by a CCD camera at different time from the SOI. Image processing techniques have enabled to get detailed informations about shape, temporal and spatial evolution of the spray, at different operating conditions. Some preliminary results of a work aiming to select and validate breakup sub-models have also been reported. Four different models (TCH, WH, KH-RT, TAB) have been tested in order to find out the one that better simulates the spray features. The analysis of results points out the following considerations: 1. the experimental set up and the used image processing technique have enabled to obtain detailed information about shape, structure and morphology of the spray, allowing also their quantitative description, in terms of spray cone angle, tip penetration and velocity; 2. backpressure effects on the sprays are analogous to Diesel sprays ones. Increasing the backpressure, spray penetration and \elocity reduce, spray cone angle increases. The fluid-dynamic interactions between gas and liquid produce disturbance waves with decreasing wavelength at increasing backpressures; 3. increasing injection pressure, tip penetration slightly increases, being jet morphology and evolution quite similar; 4. the agreement between experiments and calculations, in terms of tip penetration, is quite good for all the tested models at atmospheric backpressure but, if this one increases, only the TCH and WH models keep satisfactory predictions; 5. only the TCH model seems to show a good agreement in terms of spray morphology. Some important phenomena are captured in its computations: the shape and structure of the spray, the spray variations due to the different values of the injection pressure, the fuel-gas fluid-dynamic interaction with the formation of finely atomized droplets, the reduction of droplets momentum, the penetration decrease; on the other hand, there is a slight underestimation of the breakup process location, particularly at higher backpressures. WH model needs further work to better evaluate and improve its morphology predictive skills The numerical code, set up for single-hole injectors and single injection strategies, has now to be tested with multi-hole injectors and multiple injection strategies.