Recent experimental results have shown that the penetration length of the liquid phase in a Diesel spray under normal operating conditions is relatively short compared to the penetration length of the overall jet. In addition, the results indicate that, for a significant fraction of the injection duration, the mass and volume of the injected fuel that is in the liquid phase is relatively small compared to the total volume and mass of fuel injected. Based on these considerations, a Virtual Liquid Source (VLS) model for Diesel sprays has been developed which treats the liquid region of the spray as a source of mass, momentum and energy without directly computing the liquid phase. The penetration length of the liquid phase along the axis of injection is obtained from recent measurements. In this work, this model is described, comparisons are presented of computed and measured spray penetrations and spray dispersion angles and the sensitivity of the computed results to model input parameters is evaluated. It is shown that the model gives adequate agreement with the experimental results in the range of conditions considered.