Pressure evaluation of spray induced flow by means of URANS and time-resolved Stereo Particle Image Velocimetry

In the present work, pressure distributions of spray-induced flow are obtained by means of time-resolved stereo Particle Image Velocimetry. Revealing an extensive insight in the nature of spray transport, the characterization of pressure, material acceleration and instantaneous velocity provides a comprehensive description of spray induced flow dynamics. The pressure evaluation is conducted by an extended formulation based on the Unsteady Reynolds Averaged Navier-Stokes Equations and ensemble averaging. Assuming adiabatic flow and perfect gas the effect of compressibility is taken into account. In order to achieve phase discrimination and image contrast enhancement, optical filtering is applied by doping the gaseous phase with fluorescent tracer particles. The measurements are performed with gasoline direct injection 2-hole research samples. Demonstrating the capacity of pressure evaluation, pressure fields of spray-induced flow are successfully obtained. The investigations reveal characteristic flow patterns in accordance to air entrainment and fluid displacement. In respect to single spray plumes, high pressure regions are identified in front of the spray and the wake flow, whereas low pressure regions are present at central position. ... mehrThe pressure evaluation exposes minimal pressure differences.